Broccoli pests and diseases

How to Stop Bugs From Eating Your Plants

Springtime is here, and we’re all itching to get outside and get busy bringing our gardens back to life for the year. We’re excited to see our favorite perennials pop back up, and maybe we’ve got some new plants that we want to introduce as well. Even our indoor plants are perking back up again, bolstered by the lengthened hours of sunshine.

Of course, as delightful as this season is for experiencing the full beauty of your garden, it isn’t without its challenges. Weather and temperatures can be unpredictable. Diseases can creep into your garden. And of course, what would springtime be without the sudden appearance of tiny little holes in your plant leaves?

But what causes these holes? How can you prevent them, and how can you stop them from worsening? Today, we’re going to talk all about it.

Why Do Your Plants Have Holes in Their Leaves?

While the occasional hole in a leaf might be because the leaf was malformed or perhaps your kids thought it would be fun to poke holes, it’s easy to tell when there’s something much more serious going on. If every leaf on your plant is covered in regular holes, there’s clearly a systematic problem. In most cases, that problem is bugs.

Whether you’re working with indoor plants or an outdoor garden, you’ll find that both are susceptible to developing bug problems. These bugs are capable of burrowing through the soil to eat at roots, climbing the leaves to chew away flowers and buds and, of course, biting holes right through the center of new green leaves.

There isn’t just one type of bug that’s solely responsible for eating away at your plants, either. Instead, many different insect species are attracted to your plants and eager to begin eating them. For the most effective anti-pest measures, you’ll need to learn about each type of bug and how to guard against them.

Why Do Bugs Keep Eating Your Plants?

Bugs eat your plants because they’re hungry and your plants are likely the best option around at the moment. While it’s unfortunate for you as the gardener, it’s also easy enough to understand why it happens. Bugs are like any other living creature, and they’re usually just looking for their next meal.

Another related question you might be wondering is why the bugs are only going for specific plants in your garden while avoiding the others. It’s because, like most of us, bugs have preferences for what they eat. If you have an infestation of aphids, for example, they’re likely to head for one type of plants. An infestation of Japanese beetles will go for something different.

Why do you suddenly have bugs this year when you’ve never had a problem in years past? Think back to what’s different about your garden this year. Did you make any new additions? Add any unusual plants? The odds are good that these new plants are responsible for attracting your new visitors.

Wondering how to stop insects from eating plant leaves? It’s possible, but it takes planning and dedication. The reward will be worth it, however, when you see your plants begin to thrive once you’ve successfully removed all the bugs. Today, we want to walk you through the process of naturally getting rid of bugs that are eating your plants without hurting the plants in the process.

What Are the Most Common Plant-Eating Bugs and Insects?

Curious which bugs are likely responsible for the holes in your leaves and the droopy-looking plants in your garden? Take a look at our list of likely candidates.

Indoor Pests

Some of the bugs that might be causing your indoor plants to droop include:

These bugs are easy to pick out for their unique pale-green color. Unless you’re looking closely, aphids are almost easy to mistake for very tiny leaves. Closer inspection will reveal them to be very small, pear-shaped bugs with long antennae and two tubes pointing backward from their abdomen. These pests are frustratingly common and enjoy eating everything from fruits and vegetables to flowers and outdoor trees. Rather than chewing holes in leaves, however, they prefer to suck the sap out of plants, causing the leaves to droop and spreading disease in their wake.

2. Mealybugs

These little white bugs are especially attracted to houseplants, and you’re most likely to find them at the small joint where the leaf meets the stem in your plants, as well as on the stems and leaves themselves. Like aphids, they feed on the plant’s sap instead of chewing on the leaves directly, causing the plant to wilt and eventually die if left unchecked.

3. Spider Mites

While these pests are technically arachnids instead of insects, there’s effectively no difference when it comes to how destructive they can be. These mites look like tiny red dots that collect on the underside of leaves, where they eat plant fluids and leave tiny dots at any location where they’ve been munching. While they can infest any household plant, they’re especially common in ivy and can cause a plant to yellow, wither and die.

Outdoor Pests

While some of the indoor bugs, like aphids, can occur outdoors as well, you’ll likely have a new set of insects to worry about in your outside garden. A few of the important ones to keep an eye out for include:

1. Japanese Beetles

Japanese beetles are pests that you can find in almost every state east of the Mississippi, where they feed on many different flowers, fruits and vegetables. You can easily tell where they’ve been by the way they turn leaves into patchy skeletons, eat away at flowers and, in some cases, strip a plant entirely bare of any foliage. Adults are a metallic bluish-green with metallic red wing covers, while the larvae are white grubs.

2. Tarnished Plant Bugs

These bugs move extremely quickly, and you’ll recognize them by their green-and-brown coloring, as well as the yellow triangles with black tips located on their forewings. They’re not extremely picky about their food and will eat plenty of different vegetables, fruits and flowers. Rather than chewing on the leaves, they suck out the plant juices, leaving the plant wilted, drooping and often stunted.

3. Flea Beetles

Flea beetles are another pest that you’ll find on vegetable plants throughout North America. The adults will chew round holes right into the center of leaves, which can be particularly damaging to young plants. Larvae are more likely to chew at roots. You can identify this bug by its dark coloring and its unique ability to hop like a flea when startled.

4. Caterpillars

There are many different types of caterpillars, and none of them spell good news for your garden. These insects are larvae that will one day hatch into moths, flies, butterflies and other insects, but until then, their sole purpose in life is mostly to eat. Unfortunately for gardeners, their preferred food is usually garden leaves.

Caterpillars aren’t picky about their food, which means they’ll eat away at fruits, vegetables and trees, often chewing along the edges of leaves. The good news is that these pests are usually easy to spot and recognize, making it simple to diagnose the problem.

How to Keep Bugs From Eating Your Plants

Once you’ve noticed that your plants are suffering from an invasion of insects, and once you’ve identified or at least suspect which bugs are to blame, your next step is to figure out how to keep bugs from indoor and outdoor plants alike. And while there are plenty of synthetic pest-killers out there that you can purchase for yourself by heading to the local plant nursery or home improvement store, many of us prefer a more natural alternative.

That said, let’s look at some homemade bug sprays for indoor and outdoor plants.

How to Get Rid of Bugs on Indoor Plants

Are bugs getting into your houseplants? Try a few of these homemade solutions.

The first step to getting rid of aphids is to avoid attracting them in the first place. They’re attracted to moist soil, so if you have a tendency to overwater your plants, it could explain your aphid problem. Avoid this practice, and you may have better luck staying clear of aphids in the future. If you’ve already attracted them, however, try wiping down the leaves of the infested plant with a solution of a few drops of dish soap and water. It’s also a good idea to pinch the aphids off the plant directly, especially in cases of extreme infestation.

One of the best homemade bug killers for the house, particularly where mealybugs are concerned, is a Q-tip dipped in rubbing alcohol. Simply dab it on every bug you see for a quick and efficient removal system. You may need to complete several sessions of this procedure before the infestation is under control, but it should eventually prove effective. Once the bugs are gone, prevent them from returning by not over-watering or over-fertilizing your houseplants.

Spider mites do their best work in dry conditions, meaning they love it when you let your plant go for a while without watering it. One of the best ways you can fight this pest off is by regularly misting the leaves to keep them moist. You should also dust and clean the leaves often to prevent these mites from laying eggs on them. For extreme cases, try a homemade bug spray made of water and neem oil for indoor plants.

How to Get Rid of Bugs on Outdoor Plants

Are your concerns centered more on your outdoor garden? If so, try a few of these home fixes.

Start by shaking the bugs off the plants in the early morning, before they’re at their most active. Once they’re gone for the moment, spray down the plants with a homemade insecticidal soap. A great recipe for a homemade bug spray for vegetable plants is to use one tablespoon of dish soap, one cup of vegetable oil, one quart of water and one cup of rubbing alcohol. For best results, apply this spray in the morning and be prepared to spray the plants again with water if they seem to start drooping after the treatment.

Avoid attracting these bugs in the first place by keeping your garden free of weeds all spring, at least as much as possible. Doing so means giving the bugs fewer places to hide and making your garden a less attractive spot for them. If you find yourself with a tarnished plant bug problem, however, control it by locating the nymphs and spraying them with neem oil. Finally, one of your best bets is to encourage natural predators of these bugs, as they’ll do a big part of your job for you.

A great natural bug repellent for flea beetles is garlic-based. For this remedy, you’ll need a head of garlic, one tablespoon of a dish soap that doesn’t contain bleach, two tablespoons of vegetable oil and two cups of water. Make the spray by peeling the garlic and pureeing the cloves along with the oil and water. Let this mixture sit overnight before straining it. Add the soap and mix it together thoroughly. Then, just pour it into a spray bottle and use it to cover the infected plants.

To deter caterpillars, you can try several different methods. The first is to encourage natural predators that will eat the caterpillars and thus clear them out for you. Another method is to spray the plants with a solution of neem oil and water.

Finally, you might try mixing together a homemade chili spray. To make this spray, grind three and a half ounces of dried chilies in a blender. Throw this powder into a half gallon of boiling water and let it boil for five minutes before adding half a gallon of cold water and a few drops of dish soap. Spray this mixture on the caterpillars every morning until you no longer see them.

Call in the Professionals

When it comes to bug infestations either in your garden or among your houseplants, home remedies are a great first course of action. Oftentimes, they’ll be just the trick you need to banish the bugs and get your plants looking great again.

Contact Us Today

In other situations, the bugs may persist despite your best efforts. In cases like these, it might be time to set the home remedies aside and call in professionals. If you’re based in or around the Phoenix area, we want to invite you to reach out to us here at Green Home Termite & Pest Control.

We’re a locally owned and operated pest control company, serving the area surrounding Phoenix. Because we’re a local business, we have the freedom to treat you like family, providing you with the very best in personalized services as well as the highest quality and safest products in the business. Together, our technicians have more than 30 years of combined experience, giving us the background necessary to make your pest problem a thing of the past.

Are you ready to get started finding a solution to your bug problem? Contact us today to tell us a little bit about your situation, and in return, you’ll receive a free quote.

CALL (480) 525-PEST (7378) OR TO GET A FREE ONLINE QUOTE, TO START SERVICE TODAY!

Broccoli Pests and Diseases

Keep your eyes peeled for broccoli pests and diseases as they can quickly rob you of your future veggie profits.

Can’t help you with tax, but below is a list of all the broccoli pests and diseases you’re likely to come across. For general garden problems with pests, animals, birds and diseases, see Organic garden pest control.

You might get no broccoli pests and will probably grow marvelous disease-free plants, but just in case, here are some possible challenges:

Caterpillars, which include cabbage worms, cabbage loopers and army worms:

Watch for these as they tend to invite themselves to dinner on your broccoli leaves. Your plants are goners if caterpillars eat out the growing tips.

Here’s a handy hint or two for caterpillars: Before broccoli and cabbages form heads, sprinkle the leaves with cayenne pepper powder. This should deter the little blighters.

Also of course, as well as picking caterpillars off, an organic solution is Bt (Bacillus thuringiensis). By dusting or spraying this every 7-10 days, it controls caterpillars, especially cabbage worms, the nastiest of the broccoli pests. More solutions at Organic garden pest control.

There are two types of cabbage white butterflies — large and small. Both types overwinter as pupae and in springtime they emerge as white butterflies, mate and lay their eggs which hatch into leaf chewing caterpillars about 2 weeks later.

The large cabbage white butterfly caterpillar lays a cluster of yellow eggs usually on the underside of a leaf, and the more common and destructive small white butterfly lays single white eggs.

Cabbage looper moths mainly fly at dusk and are brown with a light silver spot on each main wing. They lay many single dome-shaped eggs on the underside of leaves. The eggs hatch around 3 days and the caterpillars move by arching their middle or looping along.

Army worms are pale green when young, darkening and developing stripes and patterns after about 10 days. The moths are mottled brown and lay fuzzy pale eggs in a mass. These hatch out in 2-4 days and the worm eat holes in the leaves or burrow into the growing tips of plants.

Cabbage root maggots:
Sound awful don’t they? Broccoli think so too, as they collapse in their death throes. These broccoli pests are fly larvae the size of a grain of rice which feed on the roots.

Any sign of them, particularly if you’ve had previous trouble, make sure you firm the soil well around each seedling. This stops the larvae hatching.

Also before you mulch, make sure you put paper layers or cloth close to the stem of each plant to prevent adult flies from laying eggs in the soil.

Aphids:
Damp, humid weather seems to encourage aphids, especially in the spring. It only takes a few warm days and suddenly the crowds have arrived. Tackle aphids immediately because they can suck the sap and stop the new growth. Garlic fire spray is a winner, see Organic garden pest control.

Clubroot:
This broccoli problem is caused by a fungus in the soil. Growing your own plants from seed helps, as most clubroot fungus is introduced from brought in plants with infected roots.

Clubroot symptoms are wilted, discoloured leaves, and when you pull out a plant, its roots will be a tortured, thick mass of… well, clubroots. It’s no wonder the plant looks sick, as the roots simply are unable to do what roots normally do.

There is no effective organic treatment for clubroot fungus once it gets into your garden, so there are not many options unfortunately. Most importantly avoid planting broccoli or any brassicas in the same patch for another 4 years at least, and from then on, make sure you rotate brassicas leaving three years inbetween crops. If feasible, replace your soil.

If your soil is acidic, add lime at least 2 months before planting, because clubroot prefers acid soil conditions.

Mildew:
One of the irritating broccoli pests and diseases is mildew.

It takes a lot to kill a plant, but it will if it gets out of hand. Springtime with milder, but damp weather encourages mildew.
There are two types of mildew:
Downy mildew: is the most common and forms greyish, powdery patches, mostly on the leaves and new shoots at first. Downy mildew will invade the plant’s insides eventually, and lethally.

Powdery mildew: This is more a surface mildew, and appears in scattered patches.

Botrytis or Grey mould:
This is another one of the common broccoli pests and diseases which is caused by damp conditions. Botrytis often attacks very new seedlings, especially if the soil is highly fertilised. It starts off often on the stems as brown spots or patches which change into a greyish furry mould. Young plants especially keel over and die pretty quickly once afflicted.

Conditions that encourage mildew and moulds are over-watering, over-crowding and over-feeding. Putting seedlings that are in pots or trays outside in a breeze or good air flow will help.

Bacterial soft rot:
Wet and warm conditions can bring on this rotten problem. It’s usually in the middle of a broccoli head and starts as a small darker, soft patch. Within a week the whole head can be infected and looks, as the name says, softly rotten, sunken and brown.

If you are getting long spells of warm temperatures along with rain, then keep an eye out and remove any infected plants before it spread to your whole crop. If you need to water, do so in the morning or when the heads can dry quickly.

Some broccoli varieties are more resistant than others, and flat-headed types are naturally more susceptible to broccoli soft rot where water can sit. Dome shaped types and sprouting varieties are less likely to succumb as the water can run off easily.

For solutions to all the above broccoli pests and diseases, see Organic Garden Pest Control.

Growing Broccoli — Main page with every broccoli thing you need to know.

Useful Success Tips on How to Grow Broccoli — Extra wise tips on how to grow broccoli. Don’t miss these.

List of Vegetables — For more vegetables to grow.


Cabbage, Broccoli & Other Cole Crop Insect Pests

Aphids

Cabbage aphids (Brevicoryne brassicae).
Whitney Cranshaw, Colorado State University, www.insectimages.org

Two primary species of aphids (plant lice) attack cole crops: the cabbage aphid (Brevicoryne brassicae) and the turnip aphid (Lipaphis erysimi). Because they are similar in life habits and response to treatments, they will be considered together. Plants in all stages of growth are frequently covered with dense clusters of whitish-green plant lice. Each is about the size of a pinhead. They suck plant sap from the leaf. The a-ffected leaves curl and crinkle or form cups, completely lined with the aphids. In severe infestations, the plants wilt and die. The plants, if not killed, are dwarfed, grow slowly and form small light heads. Badly infested plants become covered with a mass of the small soggy aphids, and the dying leaves and plants rapidly decay.

Aphids are more troublesome during cool, dry weather. Because these pests are difficult to control, treatments should be applied early. On a smaller scale, as in a vegetable garden, spray foliage with soapy water, then rinse with clear water or use insecticidal soaps. Planting in aluminum foil-covered beds and filling yellow pans with water to trap the aphids are both helpful as control measures.

Turnip aphids (Lipaphis erysimi). The large, swollen aphids have been parasitized by beneficial insects.
Alton N. Sparks, Jr., University of Georgia, www.insectimages.org

On a larger scale, two or three insecticide treatments at five-day intervals may be needed to clean up plants. When 2 percent of the plants are infested with aphids, an insecticide application should be made with high spray volume and adequate pressure to thoroughly wet foliage. Because of the waxy powder that covers the bodies of the aphids and the tendency of leaves to form pockets or cups which protect aphids, it is essential to add spreader-stickers (liquid detergent, which breaks the surface tension of the spray droplets) to the spray mix. Destroy old stalks of cabbage as soon as the crop is harvested to help prevent destructive outbreaks of these aphids.

Cabbage Looper

The cabbage looper (Trichoplusia ni) is a very destructive and difficult-to-control pest of cabbage and other cole crops. It is the larva (an immature insect stage that in this case is a caterpillar) of a medium-sized grayish brown moth. The moths have a figure-8-shaped silver spot near the middle of each of the front wings. They have a wingspread of 1¼ to 1½ inches (3.2 to 3.8 cm). The moths are most active at night and fly about at plant height while they are laying eggs.

Cabbage looper larva (Trichoplusia ni) and feeding damage.
David Cappaert, Michigan State University, www.insectimages.org

The moths lay their greenish-white eggs singly and mainly on the lower surfaces of the outer leaves of the plants. The eggs are smaller than a pinhead, ridged and almost round. Newly hatched larvae (caterpillars) have dark heads and almost clear bodies. They later become pale green and have several white lengthwise stripes. Mature larvae are about 1½ inches (3.8 cm) long. They move with a looping motion, like an inchworm.

Newly hatched larvae usually eat out small areas on the undersides of leaves. As they grow, they move to the center of the plant, eating through the leaves between the veins. Large larvae are heavy feeders and may cause serious damage to cabbage heads especially when numerous. Damage, however, may at times be restricted to wrapper leaves.

In a vegetable garden, you can handpick the caterpillars. Bacillus thuringiensis (B.t.) (see Control of Cole Crop Insects section) works very well. The larvae or caterpillars do not die immediately, but they stop feeding shortly after ingesting B.t. spores.

With a larger planting, after cupping (early head formation), insecticide treatments should be made when there is an average of one larva or one new hole per 10 plants.

Cabbage Webworm

The cabbage webworm (Hellula rogatalis) is the larva (caterpillar) of a moth that has brownish-yellow front wings mottled with darker brown and pale gray rear wings. The moths have a wingspread of a little more than ½ inch (1.27 cm). When disturbed in the field, moths make short, erratic flights and come to rest quickly among the leaves of a plant or on the ground, where their color blends with that of the soil.

Cabbage webworm (Hellula rogatalis) showing lengthwise stripes.
Alton N. Sparks, Jr., University of Georgia, www.insectimages.org

Moths lay grayish-white eggs near the buds of young host plants. As the plants mature, moths begin to lay their eggs on the underside of leaves in the angle along the leaf stems.

Larval webworms are about ½-inch (1.27 cm) long when mature. They are dull, grayish yellow and marked with five conspicuous brownish-purple lengthwise stripes. Their heads are black and bear a V-shaped mark.

When they first hatch, larvae feed on either side of the partly folded leaves of the plant buds. After a few days, they begin to feed beneath a protective web made from silk-like threads that they form. Sometimes the larvae are found on the outer leaves or in the angle between the main plant stalk and the leaf. They can be detected by debris and webs at the point of feeding.

Cabbage webworms tunnel into and kill the buds of young plants. Destruction of the original bud causes the production of secondary buds that cannot mature by harvest-time. Less severe injury may disfigure the head produced from the original bud. Feeding on the outer leaves of older plants usually does little harm. Treatments applied for other pests usually keep the webworm under control.

Cross-Striped Cabbageworm

The moth of the cross-striped cabbageworm (Evergestis rimosalis) has a wingspread of about 1 inch (2.54 cm). The front wings are mottled yellowish-brown to brown and are marked with zigzag lines of dark brown. The rear wings are lighter, being almost transparent at the base, darker at the front and marked across the free end with a row of five or six small, indistinct dusky spots.

Yellow striped cabbagworm larva (Evergestis rimosalis).
Zachary Boone Snipes, ©2015, Clemson Extension

The eggs are laid in masses of 20 to 30 on the undersides of leaves of cole crops. They are light yellow, semi-transparent and overlap one another as shingles on a roof.

When first hatched, the larvae are gray. When full-grown, they are about 3/5-inch (1.5 cm) long and have numerous horizontal black stripes across bluish-gray backs. Along each side of the back is a longitudinal black stripe and below that, a bright yellow stripe. The underside of the body is light green, mottled with yellow.

Cross-striped cabbageworms prefer the tender terminal buds and the heads of cole crop plants and riddle them with holes. Eggs are laid in clusters, and large numbers of the larvae hatch on individual plants.

In a vegetable garden, you can handpick the caterpillars. In addition, treatments made for other larvae generally keep these pests in check.

Diamondback Moth Caterpillars

Diamondback moths (Plutella xylostella) are gray, about 1/3-inch (8.5 mm) long, and have a wingspread of less than 1 inch (2.54 cm). The males have three light yellow diamond-shaped markings on their wings. The moths move rapidly when disturbed. They fly short distances from plant to plant during the daytime.

The moths lay eggs singly or in groups of two or three on the leaves. Eggs are small, nearly round and yellowish white.

Life stages of the Diamondback moth larva (Plutella xylostella).
Zachary Boone Snipes, ©2015, Clemson Extension

The larvae are light green and pointed at each end. Their bodies are covered by tiny, erect black hairs. When mature they are about 1/3-inch (8.5 mm) long. They wiggle rapidly when disturbed, often dropping from the plant and hanging by silk-like threads. The larvae feed on all parts of the plant but prefer places around the bud of a young plant, crevices between loose leaves of a firm head, and the undersides of wrapper leaves. Larvae will often not eat completely through the leaf, leaving tiny “windows” of thin foliage. Their feeding may disfigure the bud of a young plant so that the cabbage head will not develop properly.

In a vegetable garden, control early infestations with Bacillus thuringiensis (see Control section) because it is not toxic to helpful insects. For larger plantings, after cupping (early head formation), apply insecticides when there is an average of one larva or one new hole per 10 plants.

Imported Cabbageworm

The imported cabbageworm (Pieris rapae) is the larva (caterpillar) of a yellowish-white butterfly. The butterflies have several black spots on their wings and a wingspread of about 1 inch (2.54 cm). They fly around cabbage plants during the day.

The butterflies lay eggs singly on either side of the leaves. Eggs are yellow, oblong, bluntly pointed at the ends, deeply ridged lengthwise and attached to the leaf by one end.

Imported cabbageworm larva (Pieris rapae).
Zachary Boone Snipes, ©2015, Clemson Extension

The larvae are velvety green. They have a narrow orange stripe down the middle of the back and a yellowish stripe along each side of the body. When mature, larvae are about 1¼-inches (3.2 cm) long. Larvae are sluggish when disturbed.

Imported cabbageworm damage is similar to cabbage looper injury. Imported cabbageworms feed near the center of plants and do more damage to the cabbage head. They do not limit feeding to areas between leaf veins, but chew through leaves indiscriminately.

In a vegetable garden, Bacillus thuringiensis adequately controls cabbageworms. Tiny parasitic wasps and predatory insects provide common natural controls. For larger plantings, after cupping (early head formation), apply insecticides when there is an average of one larva or one new hole per 10 plants.

Cabbage Maggot

Plants attacked by the cabbage maggot (Delia radicum) appear sickly, off-color and stunted. If the attack is severe, plants wilt suddenly during the heat of the day and die. Cabbage roots show brownish grooves over their surface and slimy winding channels running through the flesh.

Damage caused by cabbage maggot (Delia radicum).
Mary Ann Hansen, Virginia Polytechnic Institute and State University, www.insectimages.org

Many of the small fibrous roots are eaten off. Larvae of this insect are legless, white maggots from ¼- to 1/3-inch (6.4 mm to 8.5 mm) long, blunt at the rear end and pointed in front. They can often be found in the burrowed-out channels within the roots. Spring cabbage after transplanting and fall cabbage while still very young are the most severely injured by this insect.

The adult stage of the cabbage maggot is a fly similar in general appearance to the common housefly but only about half as long (¼-inch or 6.4 mm in length). They are dark ashy gray with black stripes on the thorax (chest region) and many black bristles over the body.

Flies are attracted to fields which are high in decomposing organic matter, i.e., fields recently turned, new ground, weedy areas or fields recently treated with postemergence herbicides. Any rotting vegetation is likely to attract flies. As flies enter a field, they fly close to the ground and deposit their small white, finely ridged eggs on the plants near where the stem meets the ground or in cracks and crevices in the soil. The eggs hatch and the very small maggots promptly seek the roots and eat into them. Each maggot feeds for three to four weeks, and the roots often become riddled with their tunnels. When the maggots are abundant, underground parts of the plants soon become honeycombed and rot. Over 125 maggots have been taken from the roots of a single plant.

The cabbage maggot can be controlled by cultural means. Any cultural practice that will reduce the decaying organic matter content of soil will reduce the chances of an infestation becoming established. Any plant material left in the garden can attract flies. If possible, till the soil four to six weeks before planting. This allows sufficient time for rotting of vegetation and may reduce the need for an insecticide treatment. Floating row covers with the edges buried well may prevent infestation.

Postemergence herbicides also contribute to cabbage maggot problems. Weedy fields where postemergence herbicide treatments are used often become infested with maggots as dead weeds decompose. Inspect these fields daily for flies and maggots a couple of weeks after herbicide use.

Harlequin Bug

Harlequin bug adult (Murgantia histrionica).
Zachary Boone Snipes, ©2015, Clemson Extension

The harlequin bug (Murgantia histrionica) is a flat, shield-shaped stink bug (3/8- inch or 9.5 mm long) with red and black spotted markings on its back. The immature stage known as a nymph has the same markings but is smaller and more round. The eggs stand on end in double rows and appear as tiny white kegs with black hoops.

The harlequin bug can cause serious damage to crucifers and other vegetable crops. Both the adult and nymph suck sap from the collard/cabbage plant, causing it to wilt, turn brown and die. Younger plants are more susceptible to the feeding. Larger plants can withstand higher populations but show reduced growth and yellowing.

Control of Cole Crop Insects

All of the caterpillars (larvae of moths and butterflies) infesting cole crops can be effectively controlled using Bacillus thuringiensis (B.t.), spinosad, or pyrethrin. B.t. is a microbial insecticide that contains spores of these bacteria and is used to control caterpillars when they feed on leaves containing the spores. B.t. works best while the caterpillars are small. B.t., spinosad, and pyrethrin are all less toxic control options. Spray B.t. early or late in the day.

Aphids may be controlled by using a commercially prepared insecticidal soap product, neem oil extract or pyrethrin, which are all less toxic control options. Harlequin bugs, stink bugs, flea beetles and whiteflies, as well as aphids and caterpillars may be controlled using cyfluthrin, cyhalothrin or bifenthrin. Bifenthrin is not labeled for use on Brussels sprouts. Read and follow all label directions on recommended pesticides. See Table 1 for a list of both natural and conventional contact insecticides for use on cole crops. Table 2 lists examples of brands and products for each insecticide, along with the pre-harvest interval (PHI). The pre-harvest interval is the time to wait between spraying and harvesting.

Table 1. Insecticides for Control of Insect Pests of Cole Crops.

Cabbage Cauliflower Broccoli Brussels
Sprouts
Aphids
insecticidal soap
neem oil extract
pyrethrin
neem oil extract
permethrin
bifenthrin
cyhalothrin
cypermethrin
insecticidal soap
neem oil extract
pyrethrin
neem oil extract
permethrin
bifenthrin
cyhalothrin
cypermethrin
insecticidal soap
neem oil extract
pyrethrin
neem oil extract
permethrin
bifenthrin
cyhalothrin
cypermethrin
insecticidal soap
neem oil extract
pyrethrin
neem oil extract
permethrin
cyhalothrin
cypermethrin
Caterpillars
Bacillus thuringiensis (B.t.)
spinosad
pyrethrin
permethrin
bifenthrin
cyfluthrin
cypermethrin
Bacillus thuringiensis (B.t.)
spinosad
pyrethrin
permethrin
bifenthrin
cyfluthrin|
cypermethrin
Bacillus thuringiensis (B.t.)
spinosad
pyrethrin
permethrin
bifenthrin
cyfluthrin
cypermethrin
Bacillus thuringiensis (B.t.)
spinosad
pyrethrin
permethrin
cyfluthrin
cypermethrin
Harlequin Bugs & Stink Bugs
permethrin
bifenthrin
cyfluthrin
cypermethrin
permethrin
bifenthrin
cyfluthrin
cypermethrin
permethrin
bifenthrin
cyfluthrin
cypermethrin
permethrin

cyfluthrin
cypermethrin

Flea Beetles
neem oil extract
permethrin
bifenthrin
cyfluthrin
cyhalothrin
cypermethrin
neem oil extract
permethrin
bifenthrin
cyfluthrin
cyhalothrin
cypermethrin
neem oil extract
permethrin
bifenthrin
cyfluthrin
cyhalothrin
cypermethrin
neem oil extract
permethrin
cyfluthrin
cyhalothrin
cypermethrin
Whiteflies
insecticidal soap
neem oil extract
pyrethrin
cyfluthrin
bifenthrin
cyhalothrin
cypermethrin
insecticidal soap
neem oil extract
pyrethrin
cyfluthrin
bifenthrin
cyhalothrin
cypermethrin
insecticidal soap
neem oil extract
pyrethrin
cyfluthrin
bifenthrin
cyhalothrin
cypermethrin
insecticidal soap
neem oil extract
pyrethrin
cyfluthrin
cyhalothrin
cypermethrin

Table 2. Insecticide Products Labeled to Control Cole Crop Insect Pests.

Insecticides & Fungicides Examples of Brand Names & Products
Bacillus thuringiensis (B.t.)
(0 days PHI)
Bonide Thuricide B.t. Concentrate
Monterey B.t. Concentrate
Natural Guard Caterpillar Killer Spray with Bt Concentrate
Safer Caterpillar Killer with B.t. Concentrate
Garden Safe B.t. Worm & Caterpillar Killer Concentrate
Southern Ag Thuricide Spray Concentrate
Tiger Brand Worm Killer Concentrate
Bifenthrin (7 days PHI) Ferti-lome Broad Spectrum Insecticide Concentrate
Cyfluthrin (1 day PHI) Bayer Bio Advanced Vegetable & Garden Insect Spray Conc.; & RTS; & RTU
Cyhalothrin (1 day PHI) Martin’s Cyonara Lawn & Garden Concentrate
Spectracide Triazicide Insect Killer for Lawns & Landscapes Conc.; & RTS2
Cypermethrin (1 day PHI) GardenTech Sevin Insect Killer Concentrate; & RTS1
Insecticidal Soap (0 day PHI) Bonide Insecticidal Soap Multi-Purpose Insect Control Conc.; & RTU1
Espoma Earth-tone Insecticidal Soap Concentrate; & RTU1
Natural Guard Insecticidal Soap Concentrate; & RTU1
Safer Brand Insect Killing Soap Concentrate; & RTU1
Garden Safe Insecticidal Soap Insect Killer Concentrate; & RTU1
Whitney Farms Insecticidal Soap RTU1
Neem Oil Extract (0 day PHI) Concern Garden Defense Multi-Purpose Spray Concentrate
Ferti-lome Rose, Flower & Vegetable Spray Concentrate
Garden Safe Fungicide 3 Concentrate; & RTU1
Monterey 70% Neem Oil Fungicide, Insecticide/Miticide Conc.; & RTS2
Natural Guard Neem Concentrate
Southern Ag Triple Action Neem Oil Concentrate
Safer BioNeem Insecticide & Repellent Concentrate
Permethrin (1 day PHI) Bonide Eight Insect Control Vegetable Fruit & Flower Concentrate
Bonide Eight Insect Control Yard & Garden RTS2
Pyrethrin (0 day PHI) Bonide Pyrethrin Garden Insect Spray Concentrate
Southern Ag Natural Pyrethrin Concentrate
Spectracide Garden Insect Killer Concentrate (with Pipernyl Butoxide)
Monterey Bug Buster-O
Monterey Take Down Garden Spary Conc. (with canola oil)
Spinosad (1 day PHI) Bonide Captain Jack’s Dead Bug Brew Concentrate; & RTS2; & RTU1
Bonide Colorado Potato Beetle Beater Concentrate
Ferti-lome Borer, Bagworm & Leafminer Spray Concentrate
Monterey Garden Insect Spray Concentrate
Natural Guard Spinosad Landscape & Garden Insecticide RTS2
Southern Ag Conserve Naturalyte Insect Control Concentrate
Note: The PHI (pre-harvest interval) is time to wait in days between spraying and harvesting.
1RTU = Ready to use (a premixed spray bottle). 2 RTS = Ready to spray (a hose-end applicator).
To protect pollinating insects, always spray as late in the evening as possible.

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PHOTO: Kevin Fogleby Kevin Fogle July 28, 2015

When growing broccoli there are a number of diseases and pests that frequently give backyard gardeners fits. The following list is not exhaustive, but it provides a general overview of some common issues impacting broccoli and other cole crops, as well as organic solutions to keep them under control.

1. Cabbage Loopers (Trichoplusia ni)


USDA/Flickr

A major pest for broccoli and other crops, cabbage loopers are ravenous leaf consumers. cabbage looper is a small, smooth, green caterpillar with very thin white lines on its back and side, and it moves in a inch-worm like motion. This larvae matures into a medium-sized, gray-brown moth that lays eggs at night. Depending on the population of caterpillars in your garden, damage can range from purely cosmetic to lethal for broccoli plants.

Pest Control:

For small-scale broccoli crops with a light infestation, hand-picking individual caterpillars is the best solution for the environment. For heavier infestations, the most effective treatment is an application of Bacillus thuringiensis (Bt) when the caterpillars are still small. Bt is also effective on a number of other caterpillar pests common to the brassica family, such as the imported cabbageworm and the cabbage webworm. For nearly complete exclusion, floating row covers can also be used to prevent the adult looper moths and other species from laying eggs among your broccoli plantings.

2. Aphids (Brevicoryne brassicae) and (Lipaphis erysimi)

Eran Finkle/Flickr

Two species of aphids, turnip aphids and cabbage aphids, are commonly found on brassicas. As sap-sucking insects, large aphid infestations can kill young plants or significantly retard growth on mature plants. To determine if aphids are an issue, lift up several leaves and look for clusters of tiny white- to light-green insects on the underside of the vegetation.

The best organic treatment for aphid infestations on your broccoli crop is spraying the plants with soapy water followed by clear water. An alternative is using insecticidal soaps. You can help lower the population of aphids in your plantings by removing old vegetation and stalks from the garden immediately after the harvest and by encouraging beneficial insects, like lady bird beetles or green lacewings.

3. Harlequin Bug (Murgantia histrionica)

Kevin Fogle

The harlequin bug is a cousin of the stink bug and an invasive species from the South that is currently working its way north across the United States. The pretty orange-and-black coloration belies the destructive nature of these shield-shaped, sap-sucking insects that can wipe out an entire crop when left uncontrolled. Symptoms of harlequin-bug infestation include visible adult insects and the wilting of leaves that turn brown and quickly die, which is caused by saliva injected into leaves, liquefying plant-based tissue so that the insects can feed on it.

Handpicking harlequin bugs early in the season will help limit population growth that occurs later in the season. One of the best organic controls is cultivating the ground in fall and early spring, which can kill a large percentage of the overwintering adult bugs. Another method that may be successful is planting a trap crop of mustard or kale to coax the insects away from the broccoli crop you wish to harvest. Floating row covers are also effective.

4. Downy Mildew

Gerald Holms/California Polytechnic State University at San Luis

A common issue with broccoli, downy mildew is caused by the fungus Peronospora parasitica and exacerbated by moist growing conditions. External signs of downy mildew include a gray mold on the lower surface of the leaves, while the upper leaves will often show signs of yellowing and will turn brown and die back. Internal damage isn’t visible until harvest, when you’ll find darkened florets.

Disease Control:

The best ways to prevent downy mildew is to grow a broccoli cultivar resistant to downy mildew, such as Green Magic or Windsor. Cultural practices are also essential to fight downy mildew:

  • Provide adequate spacing between plants to encourage good airflow.
  • Water at the base of the plant to keep moisture off leaves.
  • Remove all plant debris after harvest.
  • Regularly rotate crops to lower the incidents of downy mildew.

Some organic fungicides are also available on the market, but effectiveness of these treatments varies compared to conventional fungicides.

5. Clubroot

Rasbak/Wikimedia

Clubroot is a fungal infection that causes the root system to grow into poorly developed misshapen knots, which will eventually crack and allow secondary rot diseases to set in. This will either kill young plants or prevent mature plants from developing proper heads. Growers will first notice broccoli leaves starting wilt during warm days but bounce back at night. The daytime wilting will continue to worsen, and the leaves will likely start to yellow. To confirm the clubroot diagnosis, pull up a suspect plant and examine the root system for the characteristic root deformations.

Once your plot has been infected with clubroot, time is the only cure. Avoid planting any brassica crops, including cauliflower, cabbage and kale, in the area until the disease has disappeared. Take care not to transfer the spores to new plots via shoes, tools or irrigation water. Fortunately, clubroot can be prevented with regular crop rotation and amending your soil with lime to keep the pH slightly above 7.2, which is generally too alkaline for clubroot.

Seedling Bird Protection: How To Keep Birds From Eating Seedlings

Growing a vegetable garden is about more than sticking some seeds in the ground and eating whatever springs up. Unfortunately, no matter how hard you worked on that garden, there’s always someone waiting to help themselves to your bounty. Birds can bring a lot of color to the drab winter, but when spring comes, they may turn around and become serious garden pests. Birds are especially notorious party crashers, and often eat seedlings as they pop up from the soil.

Seedling bird protection can be frustrating, but you’ve got several options when it comes to protecting garden seeds from birds.

How to Protect Seedlings from Birds

Gardeners have devised a number of ways to keep birds from eating seedlings, ranging from the complicated to the impractical. Although you can pick up tools like artificial owls and bird scare items at your hardware store, these tricks lose their power over time. The only sure-fire way to keep the birds out of your seedlings is to exclude your feathery friends completely.

You can start by moving any food source far away from your garden. Keep your feeder stocked as an alternative source of food for birds that may be picking at your seedlings simply because they’re hungry. Once your seedlings have reached about eight inches, you can relax a little – most birds won’t bother them at this point.

When birds are eating seedlings, most gardeners will end up running for the bird netting or chicken wire. These can both serve as great exclusionary materials, provided you’ve built a sturdy frame to support them. Arches made from PVC, bamboo or soft hose can provide the support these materials need and will withstand a great deal of wind if driven deeply into the ground. Once you’ve got your material of choice stretched over the frame, pull it tightly and weight it down with rocks or secure it to the ground with landscape staples to prevent sagging.

Another option that’s still under investigation is using monofilament line to deter birds from landing in your garden in the first place. Scientists aren’t sure what it is that birds find so displeasing about fishing line, but there’s solid evidence that they want nothing to do with this material. For row crops, you can suspend a single piece of fishing line above the seedlings and secure it to stakes at both ends of the row. Thickly bedded seedlings will benefit from filament run at 12-inch intervals. Choose a 20 pound or greater line for best results.

Something is Eating My Annuals, Vegetables, and Seedlings

A Gardening Life – June 11
See of this sounds familiar: you planted small annuals and within three days their fresh, green leaves are tattered and torn. Or the vegetable seeds you planted last week poked out of the ground only to disappear.

One day that little bean plant was poking out of the soil and the day, poof! It was gone. And those small annual zinnias and marigolds that were planted over the weekend pull a similar vanishing act. Here on Sunday, stripped to the veins or totally gone by Wednesday.

In the Northeast the culprits who cause this damage are earwigs, slugs and snails. I can tell which of these has gone after my plants by looking for the slightly shiny residue that slugs and snails leave behind. If I don’t see those slime trails, the offenders were probably earwigs.

Earwigs are the insect that people love to hate. They are creepy looking with pincers that appear much more menacing than they really are. They sneak under flowerpots and drop out of the dahlias we cut for bouquets. These creepy crawlies are most problematic early in the season because they cause substantial damage on new foliage, seedlings and flowers.

Here are the two things I’d like to convey in this post. 1. Earwigs are beneficial insects. And 2. Earwigs are pretty easy to control organically.
Later in the season earwigs will be chomping on decaying plant matter. They are one of the insects that break down organic matter and return it to the soil. Early in the summer there isn’t as much for them to eat, however, so they go after your zinnia seedlings, your butterfly bush foliage, or the emerging shoots of dahlias.

Tonight I went outside and saw signs that the earwigs were shredding some of my annuals. Out came the bag of diatomaceous earth, my favorite way to stop the early damage to annuals and vegetables caused by earwigs, slugs and snails. A quick sprinkling over and around the plants is very effective. Normally I just have to do it once.

Dear Earwigs and Slugs;
Once summer is well underway there is enough for everyone. You, Earwigs, can have my dead leaves and stems and you slugs are the perfect meal for the toads. In the meantime, however, I need to protect these tender plants with a quick dusting. I hope you understand, C.L.

Here are the Profusion Zinnias with light earwig damage.

My Sedona Coleus (one of my must-have annuals) look a bit sad here…they got some cold damage shortly after I planted them, and then the earwigs started on them. Dusting time!

For a couple of days the plants look like they were sprinkled with confectioners sugar. Later the dust disappears and I forget that it was ever there.

Sharing The Wealth
Tips for Using Diatomaceous Earth
• The skeletons of diatoms are sharp so product kills the insects and slugs by cutting into them.
• You can scatter it with your hands (I usually wear garden gloves) or with a duster, but be sure not to breath in the dust. Here are instructions for making a duster out of a plastic water bottle.
• Diatomaceous earth is most effective when it’s dry so apply it after a rain and don’t turn on the sprinklers for a couple of days. If it should happen to rain right after you put the dust down, do it again once the foliage is dry.
• I usually dust my annuals immediately after planting and the dahlia shoots as soon as they poke out of the soil. I dust bean plants once the first set of leaves open up and the squash plants as soon as they sprout. Once the plants are larger you can stop dusting.

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