Petunia annual or perennial

Overwintering Petunias: Growing Petunia Indoors Over Winter

Gardeners with a bed full of inexpensive bedding petunias may not find it worthwhile to overwinter petunias, but if you are growing one of the fancy hybrids, they can cost more than $4 for a small pot. This means that you might not be able to use them as freely as you’d like. You can save money by bringing your petunia indoors over winter.

Care of Petunias During Winter

Cut the petunias back to about 2 inches above the soil and plant them in pots before the first fall frost. Check them over carefully to make sure they aren’t infested with insects. If you find insects, treat the plants before bringing them indoors.

Water the plants thoroughly and place them in a cool but above freezing location. Look for a spot in your garage or basement where they’ll be out of the way. Check overwintering petunias every three to four weeks. If the soil has dried out, give them just enough water to moisten the soil. Otherwise, leave them undisturbed until spring when you can transplant them back outdoors.

Can You Overwinter a Petunia Plant as Cuttings?

Taking 2- to 3-inch cuttings before the first fall frost is a great way to overwinter them. They root readily, even in a glass of plain water; however, the roots become a tangled mess if you put more than one cutting in a glass. If you are rooting several plants, you’ll probably want to start them in small pots.

The cuttings root so easily that you won’t have to cover them or start them in a greenhouse. Just remove the lower leaves from the cutting and insert them 1.5 to two inches into the soil. Keep the soil moist and they will have roots in two or three weeks.

You’ll know the cuttings have rooted when a gentle tug doesn’t dislodge them. As soon as they root, move them to a sunny window. They won’t need fertilizer over winter if you’ve planted them in a good commercial potting soil. Otherwise, feed them occasionally with liquid houseplant fertilizer and water them often enough to keep the soil lightly moist.

Caution About Patented Plants

Check the plant tag to make sure it isn’t a patented plant before taking cuttings. Propagating patented plants by vegetative methods (such as cuttings and divisions) is illegal. It’s fine to store the plant over winter or harvest and grow seeds; however, the seeds from fancy petunias don’t resemble the parent plants. You’ll get a petunia if you plant the seeds, but it will probably be a plain variety.

If you love that gorgeous fresh color that petunias can add to any garden, you may be wondernig – just how long would it take you to achieve the same look in yours? Once you seed or plant them – how long does it take to grow petunias and enjoy that wonderful array of colorful blooms?

Petunia seeds will germinate within one week if they are sown in ¼ deep potting soil that is both moist and fertilized. The soil temperature should be between 65 and 75 degrees Fahrenheit for optimum germination. The plants will grow fairly quickly if the proper growing conditions are met and should produce flower buds in as little as 6 to 8 weeks. Expect plants to take 10 to 12 weeks from seed sowing to flowering.

Now that you know the rate at which petunias grow, let’s take a look at this in more detail below. We will discuss how long it takes for petunias to grow from seeds as opposed to transplants. We will also explore the time it takes for the plant to bloom, what effect temperature has on their rate of growth, how long petunias last and whether or not they grow back each year.

So, if you’re ready to learn more about how long it takes to grow petunias, then let’s get started!

How Quickly Do Petunias Grow?

Petunias are a very popular flower that originated in Argentina, South America. There are many different types of petunias (over 35 known species) that come in a variety of colors, patterns, and sizes. They fill in space around plants in a garden and look beautiful against a backdrop of green foliage.

The speed at which you can get to that burst of color depends on how you grow them. Growing petunias from seed as opposed to transplants takes much longer, with more care and effort required.

Growing Petunias from Seeds

It takes approximately 7 to 10 days for petunia seeds to germinate, begin to grow and sprout. This is quite slow by growing standards. Begin indoors in late winter and sow petunia seeds in moist, fertile soil for about 10 to 12 weeks before the intended outdoor planting date in the spring.

To maintain consistent moisture levels, place a clear plastic dome, or some plastic wrap, over the planter or pot. Do not set the pot in direct sunlight at this time. The intense heat could inhibit or even prevent germination.

As soon as germinations occur, remove the dome or plastic wrap. Place the seedlings in a sunny window or under fluorescent lighting. Make sure the fluorescent lights are at least 4 to 6 inches above the plants and left on for 12 to 16 hours daily.

Growing Petunias from Transplants

Petunia transplants are easier to grow than petunia seeds with less time and effort on your part. You do not need to start them indoors and cuttings can be planted directly into a pot, hanging basket or garden bed immediately after purchasing. This saves you approximately 10 to 12 weeks of growing time.

Do Pelleted Petunia Seeds Grow Faster?

Pelleted seeds are seeds that are coated with a material to make them larger and easier to handle. Germination time can be up to 50 percent faster with pelleted (or primed) petunia seeds. The only downside is that they do not have the same storage life as unprimed seeds.

How Long Does it Take for Petunia Seeds to Grow?

Germination takes anywhere from 5 to 15 days for petunias that start indoors at average room temperature, which is 68 to 72 degrees Fahrenheit. If you are lucky enough to have a greenhouse and can keep them in a slightly warmer temperature (75 to 85 degrees Fahrenheit), they will germinate in as little as 3 or 4 days.

How Long Before Petunias Bloom?

Petunia seeds are very small and need a lot of light to germinate. They take anywhere from 6 to 8 weeks to flower. You should start them indoors in moist, fertilized soil and then move them outside after 10 to 12 weeks. Do not place them outdoors until the plants have a least 3 leaves. It is often easier and quicker to grow them from transplants.

Does Temperature Affect the Growth Rate of Petunias?

As the temperature rises, plants will grow faster. This goes for petunias as well. For the quickest flowering of petunias, they must be in areas with warm temperatures (65 to 75 degrees Fahrenheit) and long days with up to 16 hours of sunlight.

If petunias are planted in cooler temperatures (less than 65 degrees Fahrenheit), longer days will have less of an effect on their growth. They need heat to survive and to thrive. Therefore, if petunias are grown in very warm regions where the temperature reaches 75 degrees or higher consistently, they will continue to grow even in shorter days with 8 hours of sunlight or less, but not as well.

Where Do Petunias Grow the Fastest?

Petunias will grow the fastest in regions with warmer climates and hot, humid summers that are similar to Argentina, their place of origin. Long days and mild evenings (free of frost) provide the fastest growing conditions for these flowers.

How Long Do Petunias Last?

Petunias are perennials in warmer climates. They typically bloom during spring and summer, die back in autumn or winter and return again the following spring. Petunias have a natural limit to their lifespan and will eventually die back for good after 3 or 4 years. In cooler climates, they grow as annuals.

In regions where the climate is warm year-round, they often continue to bloom throughout the autumn and early winter months. It is usually recommended to keep petunias indoors during the winter if you want them to return again in the spring. Rarely will a petunia grow longer than 12 to 18 months.

Do Petunias Grow Back Every Year?

Petunias are often considered half-hardy annuals, even though they are actually perennials. They will usually survive the first frost, as long as it is light. They will not, however, survive a heavy frost and once frozen will die. Frost-injured plants can be cut back and what remains should outgrow the damage, thus allowing the plant to return again the following spring.

Summary

In summation, petunia seeds will germinate within one week, if they are sown in ¼ deep potting soil that is both moist and fertilized. The warmer the temperature, the quicker the petunias will grow. Therefore, soil temperature must be between 65 and 75 degrees Fahrenheit for optimal germination to occur.

If the proper growing conditions are met, the petunia plants should produce flower buds in as little as 6 to 8 weeks. It takes 10 to 12 weeks of indoor growing before petunias can be planted outside. Good luck and happy gardening!

George WeigelRooted cuttings in a tray ready to go inside for the winter.

Q: Last year at this time, I brought a bunch of annuals inside — geraniums, ivy geranium, a beautiful lantana, a sun fuchsia and a ‘Dragon Wing’ begonia. All did beautifully this year and saved me a lot of money. The problem is they take up so much space in the house. Is it possible to just stick all of these plants in my unheated garage for the winter? There is some sunlight there from a few windows, but it still gets plenty cold in January. Do you know if some of these “annuals” can take more cold than others?

A: A few so-called annuals go dormant over winter and survive in an unheated garage. I’ve done that myself with ‘Black and Blue’ salvia, geraniums and agapanthus.

I keep the plants in their pots, move the pots into the garage and cut back the foliage once it browns. I give them just a bit of water about twice over winter — enough to keep the roots from totally drying but not enough to stimulate new growth. Light isn’t necessary.

I’m sure the temperatures go below freezing in my garage, but it’s never been cold enough to kill these more cold-tolerant species. To be on safe side, it helps to store the pots against a heated wall — or at least away from the garage door where it’s probably coldest.

You can probably get away with this with some other annuals that can stand at least a light frost, such as lantana, dusty miller and salvia. I’ve even had dusty millers overwinter outside in the ground the past two winters.

But the majority of “annuals” are either 1.) warm-climate perennials that will die at or near frost or 2.) “true” annuals that die at the end of year one after producing new seed.

Species such as begonias, coleus, fuchsia, Persian shield and most houseplants will overwinter if you keep them above freezing. A few start to suffer when temperatures drop below 40. So get them inside in the next couple of weeks.

True annuals such as vinca, zinnias and marigolds are eventually going to croak even if you try to milk them through winter.

If you’re light on space inside, take in the most tender plants that you really don’t want to risk losing and then store the rest in pots, in soil, in the garage. Especially with a warm winter like we had last year, I think there’s a good chance a lot of species would survive.

One thing I do to save space on the tender things is take cuttings late in the season so I’ll be storing smaller “babies” over winter instead of full-sized plants.

Can annual plants live more than one year in controlled environments or in the wild, and if so, what’s the oldest living annual?

Almost any plant can go to seed and grow again the next year. Many varieties of Petunia, if allowed to go to seed, will grow as ‘volunteers’ the following season. (‘Volunteer’ is the term for an annual which has grown again the following year.) However, almost always any hybrid properties are lost in this next generation, leaving a small, single petaled pale purple blossom, instead of anything fancy.
Tomatoes, usually considered ‘annuals’, will also come up as ‘volunteers’. However, usually ‘volunteer’ tomatoes will not bear fruit, or if they do, they bear too late in the season to ripen.
It is worth remembering that the only plants which will not voluntarily grow again the following year without replanting are plants which have been engineered by humans. Hybrids, grafts, etc. Plants which did not occur naturally. The natural or native cousins of these altered plants will continue to flower year after year. Its just the way plants work. If a plant couldn’t reproduce, it wouldn’t still be here.

Make Your Annual Flowers Perennials

There’s a freeze warning out tonight in Grumpy’s neighborhood, which means his annual flowers are doomed. Or are they? Four years ago, Grumpy’s wife bought a one-gallon, coral-pink geranium and planted it in a concrete planter by our front steps. It’s still blooming. How can that be?

It’s because there are two kinds of “annuals.” The first are true annuals, like cosmos, larkspur, bachelor’s-button, celosia, and common sunflower. After they flower, they set seed and die. This is genetic programming you can’t change. The second are tender perennials we treat like annuals because of our cold winters. Remove the cold, give them winter sun, and they become perennials that you can enjoy for years. This is what we did with our geranium.

Come Inside, My Pretty

Image zoom emThe dang planter weighs a ton, so moving it takes a hand-truck. Photo by Steve Bender./em

Fortunately, our garage has windows to let in sun and it stays about 55-60 degrees in the winter. So the geranium does fine. Oh, it’ll shed some leaves because of the dimmer light, but I just pluck them off. Common geranium (Pelargonium x hortorum) has succulent stems that become woody over time. I’ve seen older specimens pruned into small trees. It needs very little water in winter — just enough to keep it from wilting — and zero fertilizer.

Achtung! Very important! (Turn off Hoda and Kathy Lee — trust me, you won’t miss a thing.) Before bringing any plant indoors that’s spent the summer outside, closely inspect it for any pests, like aphids, spider mites, scales, mealybugs, or white flies. In close quarters, one infested plant could quickly infest them all. So spray the foliage thoroughly — both upper and lower leaf surfaces — with paraffinic horticultural oil or insecticidal soap (both are natural and very safe) to kill hitchhiking pests, their larvae, and eggs. When it dries, bring the plant indoors.

Other Annuals You Can Make Perennial

Image zoom emCommon waxleaf begonias are easy to overwinter indoors in a sunny window. Photo: kafka4/em

1. Angelonia 2. Begonia 3. Coleus 4. Common heliotrope 5. Copper leaf 6. Dusty Miller 7. Impatiens 8. Lantana 9. Madagascar periwinkle 10. Pentas 11. Persian shield 12. Polka-dot plant

Petunia

Traits

  • Sun
  • Container

Flowering Season

Summer, Autumn, Winter, Spring

Genus

Best known for their showy annual and perennial hybrids, these attractive plants are members of the nightshade (Solanaceae) family, though they are more closely allied to tobacco (Nicotiana), with the leaves having a similar narcotic effect. The genus name comes from petun, a Tupian Indian name for tobacco. There are some 35 species in this tropical South American genus, and most are low spreading plants with simple, rounded, downy leaves and large 5-lobed flowers. Modern petunias are remarkably tough plants their flowers are weather resistant and in mild climates many will flower year-round.

Appearance

Most petunias are low spreading plants with simple, rounded, downy, dark green leaves and large, trumpet-shaped, 5-lobed flowers. The species come in a range in colours from white, pink, and red to blue and purple, often with a variety of multicoloured markings. The wild species are often aromatic, with scented flowers, but as is often the case the fancy garden forms have lost these charms, though they compensate with an abundance of blooms and a wealth of colour.

Cultivation

Plant petunias in a sunny position with moist well-drained soil and deadhead frequently to keep the plants flowering. While the plants need watering, the flowers are easily damaged when sprayed too heavily with water. Modern strains of the plant are more resistant to this, as well as wet-weather damage. Most petunias are raised from seed; the more reliably perennial forms all grow well from cuttings.

Gardening Australia suggests you check with your local authorities regarding the weed potential of any plants for your particular area.

© Global Book Publishing (Australia) Pty Ltd from Flora’s Gardening Cards

© MrBrownThumb Lantana.

Just about all of the decorative annuals you buy in the spring from your local garden center are tender tropical plants. In warmer zones they can be perennials–or at least live for a couple of years–but in colder zones these are plants are usually allowed to die with the first frost.

One benefit of overwintering annuals is saving money. Annuals you successfully overwinter don’t have too be bought again the following spring. If you have an annual that you absolutely loved this season you should overwinter it. Cultivars fall in and out of favor and there’s no guarantee they will be available the next year. But the biggest benefit of overwintering annuals is that they give you something to fuss over during the cold, dreary days of winter.

Here are 12 annuals I have successfully overwintered in the past.

1. Lantana
2. Coleus
3. Fuchsias
4. New Guinea impatiens
5. Begonias
6. Chenille plant
7. Mandevilla
8. Oxalis
9. Tradescantia pallida
10. Tradescantia zebrina
11. Ornamental sweet potato
12. Geraniums

Cuttings or Potted Plants?

If you are blessed with a greenhouse or have ample window space, the easiest way to overwinter your annuals is to bring them indoors before they are killed by frost. If, like me, you only have a few windows you can take cuttings of these plants (except for Oxalis) and root them on your windowsills. You don’t need any fancy equipment. An empty canning jar like the one in the post on taking tomato cuttings works fine.

Bugs

Sometimes bugs can hitch a ride indoors through potted plants. Rinse off the foliage (paying close attention to the underside of leaves) with the garden hose before bringing them indoors. Bugs aren’t really a problem with cuttings, but give them a blast from the hose just in case.

Lighting, Watering and Fertilizing

Ideal placing for your annuals is in a south-facing window. The second best window in your house is an east-facing window. Water your plants when the soil becomes dry. This will depend a lot on how warm and dry you keep your home during the winter. Change the water your cuttings are rooting in about once per week. Fertilizing annuals you are overwintering is not necessary as they are not actively growing during the winter months.

Don’t forget about those decorative peppers in fall planters. They too can be brought indoors for the winter. Did your favorite decorative annual not make my list? What annual do you overwinter every year?

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