- Companion Plants For Geraniums – Plants That Grow Next To Geraniums
- Plants that Grow Next to Geraniums
- Using Geranium Plant Companions
- Pretty planters – 20 flower container gardens
- Functional Companion Planting with Geranium Rozanne
- Geranium Overview
- All About Geraniums
- Types of Geraniums
- Care of Geraniums
- Geranium Problems
- Pelargoniums vs geraniums: can you tell the difference?
Companion Plants For Geraniums – Plants That Grow Next To Geraniums
Geraniums are beautiful and extremely popular flowering plants that grow well both in the garden and in containers. They’re popular for their bright and sometimes fragrant flowers, but they bring with them the extra bonus of being especially good companion plants. Keep reading to learn more about companion planting with geraniums and what to plant with geranium flowers.
Plants that Grow Next to Geraniums
Companion planting with geraniums is so beneficial because they deter some very common and destructive pests. Geraniums are known to repel earworms, cabbageworms, and Japanese beetles. Because of this, the best companion plants for geraniums are those that are prone to suffering from them, like corn, roses, grapes, and cabbage.
Scented geraniums are also believed to deter spider mites, leafhoppers and cotton aphids, meaning good scented geranium plant companions are almost any vegetable in your garden. Spider mites, in particular, can devastate most vegetable crops in the heat of summer, so most plants will benefit from having geraniums blooming nearby.
Using Geranium Plant Companions
For effective pest control, plant a border of geraniums around your vegetable garden or simply plant them interspersed among the vegetables, especially near plants that have suffered from pests in the past.
Plant them near rose bushes to keep the bugs at bay and to create an attractive floral accent. Even if you’re not looking for pest control, geraniums are stunning in their own right and can be paired effectively with complimentary colors.
Geraniums come in a wide range of colors, and it’s up to you how you’d like to complement them. Chrysanthemums, for example, are a great choice for geranium plant companions if you want a show-stopping bed of big blossoms in lots of hues. Most any annual or perennial sharing similar growing conditions will make an exception neighbor to geraniums.
Pretty planters – 20 flower container gardens
My neighbors and friends have a green thumb! Many green thumbs! Their hard work deserves to be shared. Take a look at what they have done to brighten up their outdoor spaces. It makes my efforts look feeble but I’ll keep on trying :). Let me show you their pretty planters – they are just delightful to look at!
Amy’s pretty planter by her walkway
Don’t you just love the gorgeous green of Amy’s sweet potato vine in her planter? Every year her vine look gorgeous!
Another planter of Amy’s on her back deck.
Some people are not only good at putting a planter together but at staging it as well! I’m on the lookout for a cut log now. I’m in love with the way this planter has been featured in Diane’s backyard!
Diane’s planter – behind a rock, perched on an upright log.
Diane’s front door planter
And oh, the pretty window boxes I’ve seen!
Angie’s gorgeous window-box.
And another one:
Another of Angie’s window boxes!
About two minutes from my house is a local restaurant. I have stopped to admire the flowers (red geraniums) numerous times! I’ve actually thought about asking how they keep their geraniums blooming so profusely all summer long.
Window boxes of geraniums. Gorgeous!
Here’s a closer look at them:
I get so envious when I see these. Mine don’t do nearly as well.
On the other wall, another type of geraniums are growing in the window boxes.
A closer look!
I love the cascading flowers, so bright and cheery! They greeting you at the front door at Mary’s house.
A cascade of flower’s on Mary’s front step. Look how gorgeous this is and it’s only one type of flower but different colors!
And then some planters hung high to add some height to the flower display.
Hanging basket to add some height to the flower garden.
Happy Fourth of July! A festive planter on Erica’s front step! More of the cascading I love.
And then there are some non-traditional planters. So beautiful for their uniqueness!
Marigolds! They look so fresh and pretty now. Look at the burst of yellow color!
Jo’s flowers in her planter are almost as tall as I am!
Love the marigolds!
I got caught snooping in this planter, trying to figure out how those marigolds were propped up to be so high. Ummmmmmm, they aren’t propped up, they just grow happily that way. Sorry for snooping Jo!!
And of course a tomato planter! Nothing better than fresh tomatoes!
Oh, and if your summer flowers run out of oomph, just squeeze in a fall flower for some new color and height. I confess, I cheat sometimes 🙂 .
My tired planter got a new bright plant to revive it.
My simple planter to add a splash of color on my driveway:
Red pot with red geranium.
I’m going to be in trouble because I was asked not to put these planters in this blog. But, it was so cutely photobombed by one of my favorite four legged friends! Hi Annie!!
Annie photobombing Lori’s petunia planter photo-shoot.
As I was taking pictures at Lori’s, I looked across the street and had to share Magaly’s planter with you! It was such a fun pop of color beside the driveway closer to the street. It wasn’t tucked right by the house and that’s why I think I noticed and loved it. I’ll have to try to do that. With a log that I need to find. Oh, these planters are inspiring me for next year already!
Planter closer to the end of the driveway.
I have had planters on my mind for a while now. Even when I drop off my kid’s at their friends homes, I check out what kind of planters there are. I LOVE, LOVE what Karyn did with her planters on the red bench. It’s a very shady area but she managed to make it so bright and inviting. I was told that Liz may have helped :).
Red bench with planters
Thank you for letting me share the beautiful flower planters I’ve seen in the last couple of weeks. I hope our summer lasts just a little longer so we can enjoy them just a little more!
Want to see some more? I went around my neighborhood again! More flower planters for you if you click through on the button below!
When I first wrote this post, the main comment I received were comments looking for advice on how to plant containers!
Other planter and container garden posts with lots of ideas and inspiration!
How I plant my front door flower container.
Make your own unique large planter (inexpensive).
Ideas from Planters in my Neighborhood.
Friends, family, and companions – everyone needs them. Our own beloved Geranium Rozanne®, too!
We’ve talked about companion planting before – a garden planting technique that involves using different species of plants in the same area for the benefit and increased productivity of all plants and flowers. One advantage of using various colours, species, growing seasons and aromas as guides to choosing companion plants is that they can help to confuse pests, making your garden more resilient than if it were to only have one plant varietay
For reasons beyond simply aesthetics (the oohs and aahs of stunningly gorgeous flowers), there are many motives behind companion planting: think function!
The “function” of plants – the actual job, role or purpose a plant has – varies and can greatly benefit one another if properly teamed up with others.
Functional Companion Planting with Geranium Rozanne
Geranium Rozanne has been well known to work hard for her companions. One of her top attractions for companion planting is that she attracts honeybees that help pollinate other plants, like vegetables and fruits. Simply choose your favorite foods – peas, beans, apples or berries – and match them up with Rozanne for a useful and tasty garden next season.
Think about aesthetics, of course, along with function as you plan for your upcoming garden. Pair Geranium Rozanne with her companions for a stunning landscape full of useful and gorgeous foliage. Plants that compliment the beautiful and functional Geranium Rozanne include Catmint (Nepeta), Lilies, Gas Plant (Dictamnus), Delphinium and Shasta Daisies (Leucanthemum x superba).
What is your favorite companion plant for Geranium Rozanne? Share with us on social media using hashtag #GeraniumRozanne.
Latin Name Pronunciation: jer-ay’nee-um
Geranium is a variable genus of hardy perennials that offers up profusely blooming plants for many situations. The lobed foliage can be as interesting as the flowers, which come in vibrant as well as more subdued shades of true blue, lavender, pinks and white. These plants bear little resemblance to the tender container plants known as Scented Geraniums, Zonal Geraniums, and Martha Washington Geraniums (these belong to the same family, but a different genus, Pelargonium).
Light/Watering: Light shade to full sun in the North and part shade in the South will allow these plants to reach peak performance. Most adapt well to short periods of dry conditions, and all respond to regular watering. Geranium sanguineum and its varieties tolerate drought, especially in cooler climates.
Fertilizer/Soil and pH: Geraniums thrive in average, well-drained soils that are slightly acid to neutral and will benefit from a light application of balanced, granular fertilizer in early spring. Short, dry periods are tolerated by most.
Pests/Diseases: No serious pests or diseases occur in this hardy group.
Reflowering: With the exception of Bigroot Geranium (G. macrorrhizum) and Bloody Cranesbill (G. sanguineum) varieties, Geraniums have a tendency to sprawl after bloom. Cut plants back hard, to 2-3 inches above soil level, after the first wave of bloom. They will respond with a fresh crop of foliage that looks attractive through the season, and possible sporadic reblooming depending on variety.
Dividing/Transplanting: Cranesbill rarely needs dividing; it is possible with some plants to separate out divisions and replant in spring or early fall. Transplant with care in early spring.
End-of-Season Care: Cut back in autumn after several killing frosts, if desired.
Calendar of Care — Geranium
Early Spring: Apply a light application of balanced or slow-release fertilizer or side-dress with compost and organic amendments when new growth appears. Supplement nitrogen during periods of prolonged rain to counter natural leaching. Water well if it is unseasonably dry as most prefer an evenly moist soil. Transplant now, if needed, and in some varieties, small pieces with roots may be removed from the edges of the plant for propagation.
Mid-Spring: Taller or sprawling varieties benefit by support with brushy twigs or interwoven, slender stakes.
Late Spring: Water if extended dry periods occur.
Summer: Groom plants by removing yellow or dead leaves. If plants are overtaking their allotted space, cut back to three inches; the new foliage will look lovely for the rest of the season.
Fall: Cut foliage back to soil level. After the ground is frozen, mulch to protect plants from heaving out of the soil in winter.
Brightly-colored in shades ranging from common pinks and reds through deep dusky blues and violets, geraniums are a common sight in most gardens today.
The term “geranium” itself is a bit misleading, because there’s actually two separate genuses that are considered geraniums. But we’ll go into that in more detail shortly!
Whether you are simply looking for a plant which can create a plethora of bright and wildly-colored flowers, or a plant that smells like cinnamon or spices, you can find a geranium that will suit you. So let’s explore this aromatic and beautiful plant at length!
Products To Eliminate Geranium Pests/Diseases:
- Neem Oil
- Safer Soap
- Monterey BT
- Garden Dust
- Hydrogen Peroxide
- Microbe-Lift BMC Fertilizer
- Mosquito Bits
- Beneficial Nematodes
- Beneficial Parasitic Wasps
- Bonide Copper Fungicide
Garden geraniums. Source: Starr Environmental
|Common Name(s)||Geranium, pelargonium, garden geranium, zonal geranium, malva, malvon, ivy geranium, ivy-leaf geranium, scented-leaf geranium, stork’s bill, rose geranium, sweet-scented geranium, Martha Washington geranium, regal geranium, show geranium, angel geranium, dusky crane’s bill, mourning widow, black widow, wild geranium, wood geranium, spotted geranium, spotted cranesbill, old maid’s nightcap, meadow cranesbill, meadow crane’s-bill, meadow geranium, plus many cultivar names|
|Scientific Name||Pelargonium x hortorum, Pelargonium peltatum, Pelargonium graveolens, Pelargonium domesticum, Pelargonium crispum, Geranium phaeum, Geranium maculatum|
|Origin||Depends on variety, but either North America, Europe, Asia, or Africa|
|Height||Anywhere from 10 inches to 2 feet|
|Light||Full sun, tolerant of partial shade|
|Water||Only when soil is dry, then a deep soaking|
|Temperature||Most cultivars prefer temperatures of 50+ degrees Fahrenheit|
|Humidity||Barely tolerates humidity but can rapidly develop diseases if too wet|
|Soil||Dry, acidic soil|
|Fertilizer||Balanced fertilizer every few weeks|
|Propagation||By cutting or by seed|
|Pests||Many sucking insects including aphids, thrips, scale insects, spider mites, and whiteflies. Also caterpillars such as armyworms, bollworms, cabbage loopers, tobacco budworm, geranium plume moth, oblique-banded leafroller, cutworms, strawberry fruitworm. Finally, Fuller rose beetles and dark-winged fungus gnats.
Geraniums are also susceptible to an extremely wide range of fungal, bacterial, and viral diseases (see article for complete list). Most common are botrytis cinerea, various leaf spots, various root rots, galls, rusts, and mosaic viruses.
All About Geraniums
A day is never wasted if you had fun. Custom art for Epic Gardening by Seb Westcott.
There are two types of plants that are called geraniums: true geraniums that are part of the Geranium genus and plants which are Pelargonium genus. Both are part of the Geraniaceae family, and are related if not identical.
Both of these plants are often confused for one another.
The majority of what gardeners consider to be geraniums are actually Pelargonium genus plants. True Geraniums are often referred to as crane’s bill or wild geraniums, and sometimes as hardy geraniums as they’re a bit more cold-resistant.
We’ll cover a bit of both here!
Types of Geraniums
The majority of plants grown in the average garden bed are going to fall into the pelargonium category, simply because that’s the category which has become most known as geranium. But we’ll cover a few true geraniums as well.
Here’s a short list of some of the different types. Between the two categories, there’s nearly 700 types of plants, but we’ll list some of the most popular!
Pelargonium x hortorum
‘Garden Geranium’, ‘Zonal Geranium’, ‘Malva’, ‘Malvon’
Pelargonium x hortorum. Source: Starr Environmental
These are the most common geranium type found at your local garden center. They create large clumps of pink, red, or white flowers atop a tall stem that rises above its fan-shaped leaves.
A hybrid, Pelargonium x hortorum is a cross between Pelargonium zonale and Pelargonium inquinans.
‘Ivy Geranium’, ‘Ivy-Leaf Geranium’, ‘Cascading Geranium’
Pelargonium peltatum. Source: nicolamikie
Fleshy, rounded leaves create a base from which stems rise, each holding 8-9 pink or streaked pink flowers in a clump. The ivy geranium is a popular variety especially in areas prone to wildfires, as it tends to be less flammable than other flowering plants.
The flowers tend to have five petals, some varieties streaked from the center of the flower up along the petals. Ivy geraniums tend to be more susceptible to some forms of disease, but can make for beautiful garden plants.
‘Scented-Leaf Geranium’, ‘Stork’s Bill’, ‘Rose Geranium’, ‘Sweet-Scented Geranium’
Pelargonum graveolens. Source: Eric Hunt
This species is known for the rose-like aroma which its leaves produce. Velvety and soft, the leaves themselves are coated in fine downy ‘hairs’ which help hold their scent.
The flowers tend to bloom with the upper two petals being much more dramatic than the lower three, almost reminiscent of some forms of pansy. However, it is the scent which continues to draw people back, and Pelargonium graveolens var. graveolens is heavily used in the perfume industry.
‘Martha Washington Geranium’, ‘Regal Geranium’, ‘Show Geranium’
Pelargonum domesticum. Source: Flowersabc
These bushy evergreens make up another large segment of the American plant market’s geranium supply. Popularized here by the varieties known as “Martha Washington”, they are heavily-flowering specimens which create large and attractive border plants.
However, not all Pelargonium domesticum are larger plants. There are some very attractive miniature-type geraniums in this category as well. Their main popularity stems from the heavy production of flowers which these plants do each year.
Pelargonium crispum. Source: Dingilingi
Sometimes referred to as ‘pansy-faced geraniums’ in the United States, the angel geranium tends to be a popular bicolored species. Similar in growth habits to Pelargonium domesticum, Pelargonium crispum has been bred to become more bushy and compact with smaller flowers.
Some cultivars may have a citrus-like scent to their leaves. They can be cultivated to produce an oil that is used for perfuming.
Other Scented Pelargoniums
Pelargonium tomentosum, the peppermint geranium. Source: Eric Hunt
There’s a huge selection of scented pelargonium species, all of which are grown heavily for perfuming purposes. Scents range from almond and apple through mints, citrus scents, nuts such as hazelnut, spices like cinnamon or nutmeg, and even celery.
While there’s simply too many species to mention that fall into the scented category, these can be extremely popular amongst growers for those unique aromas.
‘Dusky Crane’s Bill’, ‘Mourning Widow’, ‘Black Widow’
Geranium phaeum. Source: Joan Simon
Native to Europe, the dusky crane’s bill has a deep violet flower with a protruding stamen cluster emerging from petals that are turned back. This gives it a bill-like look, leading to its name.
Popular varieties of this species include “Lily Lovell” and “Samobor”, both of which are commonly cultivated in European gardens.
‘Wild Geranium’, ‘Wood Geranium’, ‘Spotted Geranium’, ‘Spotted Cranesbill’, ‘Old Maid’s Nightcap’
Geranium maculatum. Source: alice_knitter
This wild plant has its origins in and around the plains regions of the United States, but has been successfully cultivated in gardens as well. Its roots are used in herbal medicine, especially among tribal groups.
One popular variety which has won the Award of Garden Merit from the Royal Horticultural Society is the “Elizabeth Ann” cultivar.
‘Meadow Cranesbill’, ‘Meadow Crane’s-Bill’, ‘Meadow Geranium’
Geranium pratense. Source: herbslariushin
With varieties such as ‘Mrs. Kendall Clark’ having received the RHS Award of Garden Merit, the meadow cranesbill is another popular geranium variety. Native to Europe and Asia, it is widely cultivated worldwide.
This species is extremely cold-hardy, and can tolerate temperatures that dip into the single-digit negatives. That makes it much more popular as a garden plant in the snowier regions of the world.
Care of Geraniums
Overall, geraniums are pretty easy to care for. Most of your work will be comprised of deadheading hundreds of spent flowers to encourage more blossoming. The tips below will show you the best conditions for your plant to thrive in.
Light and Temperature
Geraniums are typically a full-sun plant in most conditions. They require lots of light to create all of their vibrant flowers! However, they’re surprisingly adaptable, and can be in partially-sunny conditions. For best flower production, aim for 6-7 hours of sunlight per day.
Most geraniums are quite tolerant of warm weather, but in desert climates, shade during the hottest part of the day is recommended. When the weather’s over 90 degrees, try to ensure they get a nice break from the scorching sun.
If growing your geranium indoors, aim for 6-7 hours of sunlight per day and supplement with a grow light if needed. Ideal growing conditions for indoor plants are 65-70 degree temperatures, but they’ll accept up to 85 degrees without any significant slowing of growth.
Pelargonium graveolens leaves, close-up. Avoid getting water on geranium leaves! Source: John Poulakis
All plants require water, but geraniums tend to be especially sensitive to over-watering and under-watering conditions. If the soil is right, they’re not difficult to maintain.
Water your geraniums only when the soil is dry to the touch. Just stick your finger into the soil a few inches, and if it seems a bit on the dry side, go ahead and water. If you find moisture about an inch below the surface, wait a little longer before watering.
Outdoor plants usually have a minimum of one deep watering weekly, but may require more watering during the hot summer months.
Plants in pots (both indoor and outdoor) should be given a deep watering once the soil has dried out. Allow the water to flow through all the soil until it comes out the bottom of the pot, then stop.
Hanging pots or outdoor ones may require more frequent watering, so be sure to check these regularly. Indoor plants often require less watering than outdoor ones, but will need more watering if the humidity level indoors is low or during the hotter months.
There’s no doubt that geraniums like a drier soil. Don’t use bark-based or coir-based soil as it generally holds too much water around the roots.
I recommend a blend of equal parts potting soil, compost, and perlite for your geraniums. This ensures that there’s plenty of perlite there to provide airflow in the soil and keep it from being too soggy.
If you’re lacking potting soil, don’t panic! You can make a potting mix out of equal parts garden soil, peat moss, and perlite, and then use that to blend your geranium soil.
In addition, most geraniums prefer an acidic pH level. Something in the 5.5 range will make your geraniums quite happy.
A good, balanced fertilizer is what’s recommended by most geranium societies, applied every 4-6 weeks. If you’d like to fertilize more often, make a half-strength dilution of your fertilizer and fertilize every 2-3 weeks.
Trying to encourage heavy flowering? You can switch to a 5-10-5 fertilizer and add fresh compost over the surface of the soil each fertilization. The compost provides additional nutrition, but that extra phosphorous encourages the plant to flower rapidly.
A “Mary Washington” variety pelargonium. Source: Starr Environmental
Geraniums can be propagated from both cuttings or from seed.
We all know how to plant seeds, so I won’t get into huge detail there. But geranium seeds don’t need to be planted deeply. Just enough soil to cover them is fine! And they germinate best with soil temperatures of 75 degrees Fahrenheit.
Cuttings can be taken year-round, but it’s best to wait until the plant’s not currently blooming.
To take a cutting, find a healthy stem and cut it just above a leaf node (a swollen place on the stem). Remove all but the tip leaves, and then make a second cut at the base just below a leaf node, leaving yourself with a 4-6″ long cutting.
Place your cutting into a sterile container of warm, damp potting soil. Water it thoroughly, then place it in a bright location, but not in direct sunlight. You do not have to cover geranium cuttings, as that can cause them to rot.
Water when the soil dries out, and your plant should take root within a couple weeks.
It’s surprisingly easy to repot geraniums, although older plants require a bit of pruning first.
Begin by preparing your growing medium. I recommend a mix of potting soil, compost, and perlite to ensure it’s well-draining and nutrient-dense. Moisten it slightly, just enough to make it damp to the touch but not muddy.
Trim back the branches and stems of your geranium plant to a 4″ length, trying to be sure that you cut just above a node on the branch. It will grow back quickly!
Gently tilt the old pot and slide the geranium out. Unwind any roots that have started to circle around the rest of the root clump, and trim if necessary. If any roots show signs of rot, trim those out as well.
Set your plant into its new pot at about the same height it was planted before. Hold it in place with one hand, and fill around it with fresh growing medium. Then, give it a good watering, being sure that you water until you have water freely flowing out the base of the new pot.
Be sure to place a couple inches of mulch on top of the soil to slow down water evaporation, and water when the soil beneath the mulch feels dry.
Half of your pruning for your geraniums will be spend deadheading spent flowers. It seems like a neverending task, but to encourage more flowering, you should absolutely do it!
To deadhead flowers, look at the stem beneath the flower, and trim back to just above a leaf node. That way, the plant will produce new growth at that node area and continue to blossom.
In late summer or into the fall, once the plant has begun to die back, it’s time to prune perennial geraniums. Trim the plant to 2-3″ above the soil’s surface. Whenever possible, cut just above a leaf node to encourage future growth, but shape it down low.
Mulch around the base of the autumn-pruned plant for winter root warmth, and it will grow back slowly during the winter and much more rapidly come springtime.
Pelargonium peltatum. Source: Futureman1
There’s quite a few pests that geraniums have to contend with, as well as a number of diseases. While you’re not likely to experience these problems constantly, here’s how to handle them if and when you do!
Geraniums are warmth-loving plants. If the weather gets too cold and the plant is not protected, it can cause yellowing or reddening of the leaves, wilting, and possibly even plant death.
To prevent these problems, be sure your geranium is kept warm during the winter. If it’s under 50 degrees, consider using a cold frame or other outdoor protection, place it in a greenhouse, or bring your plant indoors if it’s in a pot.
Oedema, also known as edema or corky scab, is another problem that primarily affects ivy geraniums. When the air is cooler than the soil temperature but humidity both in the soil and air are high, it can cause oedema.
This condition creates watery blisters on leaves that rupture and turn yellow or brown, and can be mistaken for forms of rust. To prevent oedema, keep the air humidity low and don’t overwater. Air temperature should be kept at or above the soil temperature as well.
Speaking of overwatering, improper irrigation is a regular issue for geraniums. Overwatering can cause leaf yellowing, but so can underwatering. Check the soil if your plant starts developing yellowed leaves, and if it’s too wet, reduce your watering frequency.
Underwatering can cause reddening of leaves, or crisped edges of leaves. Again, check the soil and if it’s dry, water your plant.
Some nutrient disorders or deficiencies may also cause reddening or yellowing of leaves, but checking your irrigation status first is usually the best choice. If your irrigation level is good, then move on to having the soil analyzed and checking for signs of plant disease.
Geranium phaeum flower closeup. Source: Joan Simon
There are a number of sucking-type pests that go after geraniums for their inner juices.
Aphids are quite common in gardens, and they like geraniums almost as much as they like our edible plants. They group on the underside of leaves and along stems.
Scale insects, especially two types of mealybug (the citrus mealybug and Mexican mealybug) and the cottony cushion scale, are also prone to attack your geranium plants. These can create little fluffy, cottony masses on the leaves and are easy to identify.
The twospotted spider mite will also attack geraniums, although they typically only go after plants in drier conditions. These can create web-like masses on the leaves.
Thrips, especially western flower thrips, can often be found on the flowers or buds of geraniums. These may also be found on the leaves.
And finally, there’s whiteflies. You may find clouds of tiny white bugs flying above your plants, and that’s a sure sign that they’re present. Their larvae will be hiding on the underside of leaves, sucking the juices out of them.
On the bright side, there’s a couple things you can do to conquer all of these pests. Spray your geraniums regularly with neem oil to keep them at bay and to smother their eggs. Release ladybugs and lacewings around your garden during spring and summer to help kill them off.
You can also use insecticidal soaps like Safer Soap against these pests, if neem oil isn’t available. But I honestly recommend keeping neem oil at hand for the sucking pests at all times! A weekly or biweekly application of neem keeps them at bay.
A huge list of moth larvae feast upon geraniums, too. And unless we want a plant’s leaves to look like Swiss cheese, they need to be controlled quickly and effectively.
Armyworms, particularly the beet armyworm, are quite fond of geraniums. While they’ll go towards edible plants first, they’re more than willing to feast upon your geraniums next if they’re not dealt with.
The bollworm may be more of a curse to cotton growers than to home gardeners, but if you live anywhere near cotton farms, you’re susceptible. These hungry little caterpillars will chew through your leaves.
Cabbage loopers are common throughout the United States and in many other countries. Like armyworms, geraniums are not their primary choice, but they’re certainly not unwilling to chew huge holes in your leaves.
The geranium or tobacco budworm is a moth larvae who specifically targets both geraniums and tobacco, along with petunias and other common flowering plants. Widespread through the western United States, it’s found in lesser numbers worldwide.
Another larval pest that targets geraniums is the geranium plume moth, which is also widespread throughout the western USA. The adult moth has frilled wings and looks like a cross between a moth and a butterfly. Their caterpillar form is particularly destructive to flowering plants.
The oblique-banded leafroller is a moth that’s native to North America. Its larvae feed on an extensive range of plants. While geraniums are one of their targets, so are roses, rhododendrons, strawberries, carnations, honeysuckle, and azaleas. These also attack trees like willow and pine!
The omnivorous leaftier is sometimes called strawberry fruitworm because it attacks strawberries. But it will happily consume geraniums as well, and it’s best to keep a watchful eye out for this moth and its caterpillars.
And finally, there is the variegated cutworm. Like all caterpillars, these small larvae feed on plants. However, they’ve earned their name by eating through stems, causing the stem to topple over as if it were cut. These can be absolutely deadly to young geranium plants.
Like the sucking insects, there’s one primary control method that I recommend for all of these. Spraying or powdering your plants with bacillus thurigiensis, also known as BT, will eradicate a couple hundred species of caterpillars.
I recommend Monterey BT as a spray, or Garden Dust as a powdered form. Both will work quite effectively without harming beneficial insects.
Geranium maculatum. Source: amy_buthod
The Fuller rose beetle, aka the rose weevil, is as inclined to consume geranium plant matter as it is to go after roses. The adults will eat the plant’s leaves, where larvae go after the plant’s roots. A bad infestation can easily kill your geranium plants.
It’s important to control these beetles in their adult form, before they can lay eggs. Neem oil is considered to be an effective deterrent against the Fuller rose beetle, and can smother their eggs.
Once larvae form, beneficial nematodes in the soil will also attack the weevils, as will parasitic wasps.
And at the end of this long pest list, we have the sciarid fly, known as the dark-winged fungus gnat. While the adults are mostly just an irritant, their larvae will live within your soil and do root damage to your geranium plants.
Using the common household version of hydrogen peroxide as a soil drench is quite effective at killing the larvae of fungus gnats, as is neem oil.
A species of BT that’s not in most commercial sprays or powders, Bacillus thurigiensis var. israelensis, can also be used to kill fungus gnat larvae. You can find this in Microbe-Lift BMC Fertilizer if you need to fertilize your plants. Alternately, water in some Mosquito Bits to get it in your soil.
Fungal issues like Armillaria root rot, botrytis blight, Alternaria leaf spot and other leaf spots, pelargonium wilt, and verticillium wilt are common problems for geraniums.
Armillaria root rot is caused by the fungus Armillaria mellea. It causes stunted growth and wilting on geraniums, as well as leaf drop. Honey-colored mushrooms may form at the base of infected plants, although that’s more common on trees. Destroy infected plants and remove all root material.
Botrytis cinerea creates greyish, mold-looking spore infestation across leaves and can be fatal to plants over time. Treatment is a bit complex, so I recommend you read my article on how to handle botrytis cinerea infestation.
A variety of leaf spots tend to be caused by fungal growths, and many of them cause damage to geraniums. The worst of these is alternaria leaf spot, which causes brown spots with a yellowish halo around them. Use a liquid copper fungicide to treat these conditions.
Geranium rust, occasionally referred to as pelargonium rust, can cause yellow spotting with dark brown pustules filled with fungal spores. Neem oil can help protect your plants’ foliage from developing this disease.
Finally, we come to the last fungal issue for geraniums, verticillium wilt. Wedge-shaped yellow patches on leaves will form. Quickly thereafter, the entire leaf may yellow, wilt, or simply fall off. Plants will become stunted and may have limp branches.
Geraniums showing the symptoms of verticillium wilt should be removed completely and destroyed. This fungus lives in the soil, so new plants susceptible to verticillium should not be placed in that soil unless it’s fully heat-sterilized.
Geranium pratense. Source: CameliaTWU
Bacterial infection for geraniums tends to be uncurable. Prevention is your best defense.
Bacterial leaf spot or bacterial blight are some of the most common diseases of geraniums. There are multiple bacteria, but the most prevalent are Xanthomonas campestris pv. pelargoni, the Psuedomonas species Pseudomonas cichorii and Pseudomonas syringae pv. syringae, and Ralstonia solanacearum.
Most of the bacterial leaf spots and blights are spread by water splashing onto the leaves or through infected soil. While there are some chemical bactericides which may be partially effective, these bacteria are notoriously hard to wipe out. Destroy infected plants.
Blackleg is a common infection for geraniums which turns the stems a distinctive black color and causes them to wilt, as well as causing root rot. Plants infected with blackleg will not recover, and should be destroyed.
A pair of gall types also tend to strike geraniums.
Leafy gall causes a cluster of strangely-shaped leaves to appear right at the soil line. This bacteria is transmitted through the soil, and infected plants should be destroyed. Avoid planting new geraniums in that spot.
Crown gall causes distorted growths or galls directly on the plant’s stem. These galls make it difficult for the plant to take up water or nutrients. Plants with galls should also be destroyed, and again, avoid planting geraniums in that spot.
There is also a long list of viral diseases which can affect geraniums. Like the bacterial diseases, these have no known remedy. Infected plants should be destroyed to prevent viral spread.
Two mosaic viruses, the cucumber mosaic virus and tobacco mosaic virus, can spread via aphids, virally-infected seed, or via human hand on tools. These cause mottling and streaking of the geranium leaves, as well as blistering or crinkling of the leaves.
Curly top, also referred to as beet curly top virus, causes thickening of the leaves and twisting and deformation. Leaves may yellow, as well. Younger plants often will die off quickly, while older plants may hold on for a while.
Impatiens necrotic spot virus and tomato spotted wilt virus were originally considered different strains of the same virus, but now are viewed separately. Both cause a wide variety of symptoms including yellowing, spotting, discoloration, stunting, wilting, and stem death among others.
Pelargonium flower break causes stippled yellowing of leaves, leaf edge browning, and yellow veining. This disease is widespread in greenhouse environments.
Finally, there is the tobacco ringspot virus. Transmitted by everything from nematodes to honeybees, this virus causes irregular yellow splotches on leaves, crook-shaped stems with drooping flower heads, browning and rolling of leaves, and other symptoms.
Most of these viruses are transmitted by pest populations. If you keep your plants free of pests, you will greatly reduce your chances of plants developing these viral infections. Destroy any plants which are infected to prevent spread of the diseases.
Whether you’re growing them for their luscious scent or their showy blooms, geraniums are definitely worth growing! What’s your favorite variety of geranium? Let me know in the comment section!
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Pelargoniums vs geraniums: can you tell the difference?
Often classed as a separate group are Angel pelargoniums (mostly derived from Pelargonium crispum) but they are very similar to Regals, just more compact and bushy. Flowers have a pansy-like appearance.
As their name suggests, this group of shrubby evergreen perennials are mainly grown for their fragrant foliage. The scent is emitted when the leaves are touched or bruised.
Flowers, although small, have a delicate beauty ranging from deep crimson to pale pink.
Heights are variable: some grow to over a metre; others only reach 30cm. Tip pruning can easily help control height.
Scented-leaved pelargoniums are very drought- and heat-tolerant. Over 400 years of plant breeding has produced 140 varieties with an impressive range of perfumes. These include rose, lime, lemon, nutmeg, peach, lemon, cinnamon, eucalyptus, grapefruit, almond ginger, nutmeg, oak, peppermint, strawberry, balsam, apricot, coconut and apple. Not surprisingly, many are grown commercially for their oil, which is used by the perfume industry.
Leaves can also be used medicinally as well as for potpourri, cooking, jams, even popped into a cold drink. Many are great plants for attracting pollinators to the garden.
PARKS WHOLESALE PLANTS Interspecific pelargonium ‘Caliente’.
In recent years, plant breeders in the US have created a new class of pelargonium by crossing Ivy-leafed geraniums with Zonal types. Said to provide new forms and colours as well as better performance, these interspecific pelargoniums, such as the Caliente and Calliope series, combine the heat tolerance of Zonals with the superior flowering ability of Ivy-leaved types (up to a third more blooms than Zonals).
Zealandia Horticulture supplies ‘Big Red’, one of the US-developed Calliope series to New Zealand retailers. “We have found this to be a superb growing plant which produces masses of beautiful, deep red flowers with the most intense colouring you will find in the market,” says its national sales coordinator Aaron Blackmore. “The plant itself has good vigour and will form a decent-sized bush that, at maturity, will produce more quality flowers than any conventional varieties that we have grown. “
Another red-flowering interspecific called ‘Cassiopeia’ will be released this year by Invercargill-based Hayes Wholesale. Founded by Barry Hayes 35 years ago, the company is the largest supplier of pelargoniums in the country as well as the New Zealand representative for ‘PAC’ varieties from Germany.
The best way to ensure you have a continuous supply of strong, healthy plants as your pelargoniums age is to take cuttings. Most gardeners know they are among the easiest plants to propagate from cuttings, but for best results:
• Take cuttings while plants are actively growing, which can be year round in many parts of the country.
• Make cuttings about 4-8cm long using a sharp knife. Cut just above a leaf joint on the main stem and strip off most of the leaves.
• Fill pots with a mixture of two-thirds potting mix to one-third vermiculite or crushed pumice.
• Leave uncovered but don’t let them dry out. Cuttings should root within a few weeks if positioned in a light, dry location.
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