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Dahlias in pots over winter


How To Overwinter Dahlias (Storing Dahlia Tubers & Winter Care Tips)

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Overwintering dahlias is not hard, and it’s well worth the effort to keep them year after year. In this post, I’ll show you three methods to try, as well as when and how to dig up the tubers, instructions for storing them, winter care tips, and much more.

No matter where you live, you can easily keep dahlias over winter, and regrow them every year. Even if you live in a frozen tundra like I do here in Minnesota.

Thank goodness, because I love dahlias. They are a gorgeous addition to my summer garden, and they add such a cool tropical feel.

 

Overwintering dahlias is not only convenient, it’s a huge money saver too. It means that you don’t have to buy new ones every spring. Woohoo!

Below I’m going to walk to you through three different methods of saving dahlias tubers over winter. I’ll tell you everything you need to know, and make it super simple for you.

Table of Contents

Will Dahlias Survive The Winter?

Believe it or not, dahlias can survive the winter as long as you use the right method to overwinter them.

Though most people buy them as annuals, they are tender perennials. That means they can live for many years in the warmer areas of zones 8 and above.

But if you live in a cold climate like I do, they won’t survive through the winter outside. So we must bring them indoors if we want to keep them.

Related Post: How To Overwinter Plants: The Complete Guide

Dahlias blooming in my summer garden

Methods Of Overwintering Dahlias

When it comes to overwintering dahlias, you have three options to choose from. I will describe each method in detail in the section below.

  1. Leaving dahlias in the ground over winter
  2. Overwintering dahlias in pots
  3. Digging and storing dahlia tubers for winter

How To Overwinter Dahlias

Deciding which method to use for keeping dahlias over winter will depend on where you live, and also where you planted them.

1. Leaving Dahlias In The Ground Over Winter

If you live in zone 8 or higher, then you can leave your dahlias in the ground over winter. They will stay alive and continue to bloom year round in frost-free areas.

But the foliage will die back and the tubers will go dormant if the air temperature gets below freezing. In that case, cut the plant all the way down to the ground once it dies.

Some people in as low as zone 7 have been able to leave them in the ground in either a warm microclimate in their yard, or by giving them extra winter protection. They will survive long as the ground never freezes.

2. Overwintering Dahlias In Pots

You can leave dahlias in pots over winter too. If you want to try this method, then leave them outside until frost has killed the foliage.

Leaving them outside when the weather cools down in the fall will trigger dormancy. Once the leaves die, cut them back to the soil level, and move the container indoors before freezing temperatures arrive.

If a hard freeze is in the forecast, move the container into an unheated garage or shed to protect them.

The goal is to keep the pot cool enough so that the plant will go dormant before bringing it inside, but the bulbs won’t freeze.

3. Digging & Storing Dahlia Tubers For Winter

The most popular method of overwintering dahlias is digging up and storing the tubers. If yours are planted in the garden, then this is the method you’ll need to use. Don’t worry, it’s simple.

As the weather cools down in the fall, they will start to naturally go dormant. You can leave them in the ground until they are completely dormant, or wait until the first hard frost kills the plant.

There’s no rush to get them out, which is part of what I love about them. However, you’ll definitely need to lift them before the ground freezes.

Related Post: How To Store Bulbs For The Winter

Dahlia Rigletto planted in the ground

Preparing Dahlias For Winter Storage

If your dahlias are in the ground, then follow these tips for when and how to dig them up and prepare them for winter storage.

When To Dig Up Dahlias

The good news is that you have a lot of time to dig up your dahlias. They are very forgiving, and the tubers won’t be hurt by frost.

The best time to lift the bulbs is after frost has killed the plant, but before the ground freezes. Exposing them to cold temps will trigger them to naturally go dormant, so it’s much easier to store them.

How To Lift Dahlia Tubers

To lift dahlia tubers, I like to use a garden fork, but a spade shovel would work too. In order to avoid cutting or damaging the bulbs, start digging at least a foot away from the center stem.

After you pop them out, gently shake off any excess dirt, and then cut off the stem and leaves.

There’s no need to rinse the dirt off or split the bulbs apart. Just leave them in one large clump with a little bit of soil, and they’re ready for winter storage.

Drying Dahlia Tubers Before Overwintering

Before storing dahlia tubers for winter, you should cure (dry them) first. That way there’s less risk of them rotting or molding.

Allow large clumps to dry for at least a week, and smaller bulbs only for a few days. To do that, spread them out on a shelf or the ground in a cool, dry location – I cure mine in the garage.

Curing my dahlia tubers before storing and overwintering them

How To Store Dahlia Tubers Over Winter

Below I’ll give you the steps for how to overwinter dahlia tubers, and where to store them. If yours is in a pot, then you can skip the section about packing them, and just store them right in their container.

Packing Dahlia Bulbs For Storage

After digging and curing your dahlia tubers, it’s time to pack them up for storage. Some people have great success just tossing them into a paper bag, or loosely wrapping them in newspaper.

But smaller ones can dry out that way. So instead, I pack mine in a cardboard box filled with peat moss or coco coir.

You could use a similar packing material like pet bedding, sawdust, or a mix of vermiculite and perlite if you prefer. Any of those would work great too.

Place individual bulbs or clumps into the box so they aren’t touching each other, then completely cover them with packing material. As long as they aren’t touching, you can layer several tubers in one box.

Whatever you do, don’t use plastic bags or containers to store them. If they are kept too wet they will likely rot or get moldy.

Where To Store Dahlia Tubers

Where you store dahlia tubers for winter is important. Keep them in a cool, dark, and dry location that stays above freezing.

Ideally, the temperature range should stay between 50-60°F. If it’s too warm or cold, your bulbs could rot. Good options are a heated garage, unfinished basement, a cool closet, or root cellar if you have one.

My dahlia tubers packed in a box and ready for winter storage

Dahlia Winter Care Tips

Besides keeping them from getting too hot or cold, there’s not much you need to do to care for dormant dahlias over winter.

It’s a good idea to check on them every so often to make sure they aren’t drying out too much, or staying too wet. If you find any that are molding, then discard them so it won’t spread to the others.

On the other hand, if they seem to be drying out too much, then you can spritz them with water to rehydrate them a bit. Just make sure they aren’t too wet.

Replanting Dahlia Tubers After Overwintering

When you successfully overwinter dahlias, you might find that you’re very antsy to get them replanted in the spring. But hold on! In order for them to survive, you must do it at the right time.

When To Plant Dahlias

You should wait to plant dahlia bulbs until after all chance of frost is gone, and the ground has warmed up in spring or early summer.

Take care not to plant them too early, or they may not grow. Ideally the ground temperature should be at least 60°F (you can use a soil thermometer to check it).

How To Prepare Dahlia Bulbs For Planting

There isn’t anything special you need to do to prepare dahlia bulbs for planting. Many people have success pulling the dormant tubers out of storage, and planting them directly into the ground.

However, to wake them up faster, you could soak them in warm water first. I like to soak mine in a compost tea solution to help break dormancy, and give them a little extra boost. But this step is completely optional.

Starting Dahlia Tubers Indoors

If you’re too impatient to wait until it’s warm enough outside, you can start dahlia tubers indoors 4-6 weeks before you want to plant them.

Pot them up into a container that has drainage holes, give them a good drink of water, and place them in a warm and sunny location. Using a heat mat will help them break dormancy faster.

A magenta dahlia flower in my garden

FAQs About Overwintering Dahlias

Below I will answer some of the most frequently asked questions about overwintering dahlias. If you can’t find your answer here, ask about it in the comments below.

Can dahlias grow indoors over winter?

While you certainly can grow dahlias indoors over winter, it’s fairly difficult to keep them thriving. They need a lot of sunlight, and are prone to bugs infestations.

You’ll likely find that it’s much easier to overwinter dahlias in their dormant state, rather than trying to keep them alive indoors.

Can you overwinter dahlias in pots?

Yes, you can overwinter dahlias in pots, and it is very easy. Once frost has killed the plant, simply cut it back, bring the container inside, and store it in a cool, dry place until spring.

Can you leave dahlias in the ground over winter?

Yes, you can leave dahlias in the ground over winter if you live in zones 8 or higher. As long as the ground doesn’t freeze, they will survive just fine outside.

How long can you store dahlia tubers?

You can store dahlia tubers for several months without any problem. However, if you store them for too long, they will eventually dry out and die. So it’s best to replant them every year, even if you can’t get to it until later in the summer.

Overwintering dahlias and storing the tubers is very easy, and a great way to save yourself some cash. Plus you’ll be able to keep your favorite varieties for many years to come.

If you want to learn all you need to know in order to successfully keep plants alive thorough the darkest and coldest months of the year, then you need my Winter Houseplant Care eBook. It will show you exactly how to keep indoor plants thriving no matter what the weather is outside. Download your copy today.

Most Posts About Overwintering Plants

Share your tips for overwintering dahlia tubers in the comments below.

How to overwinter dahlias | Homes & Gardens

(Image credit: Getty Images)

As the first frost heralds, it is time to figure out how to overwinter dahlias. Dahlias will continue to flower with their beautiful blooms right up until the temperature drops and the frost arrives. At this point, any remaining flowers, buds and foliage will die immediately. So it is time to start the process of protecting your dahlias from the cold winter weather so that they can regrow next year. 

Just like when learning how to grow dahlias, figuring out how to overwinter dahlias can seem quite daunting – especially if it's your first time. Should you dig them up or leave them in situ? How should you store the tubers? Will they regrow next year? All these questions are very important and the answers depend on both your area and personal preferences.

There are lots of different methods available for overwintering dahlias, which means there will be a little bit of trial and error as you figure out the best way in your specific part of the world. Why not try several different approaches to see which works best for you and your winter garden ideas?

(Image credit: Getty Images)

How to overwinter dahlias: step-by-step

Planning a winter garden does involve preparing more tender plants for dormancy during cold weather. The key thing to remember when learning how to overwinter dahlias is that the tubers should not be left to totally dry out, as you would with bulbs. 'Dahlias require a cool climate, ample air circulation, and being placed in a dark area if they are not being stored in soil media,' says Tammy Sons,  owner of  Tennessee Online Plant Nursery .

  1. The first frost marks the start of the overwintering period. 'Wait until a frost has turned the foliage black, then cut the plant down to about 6 inches,' advises Tamsin Hope Thomson from Amateur Gardening Magazine , 'Then lift the tubers and use your hands to get rid of the soil.'
  2. Having lifted your tubers, the next step is to remove any rotten or dead matter. The tuberous roots should feel firm to the touch and not squishy when pressed. If they don't feel firm or if they look rotten, then remove the rotten material with a clean knife until only healthy tuber remains. Dispose of any unhealthy material on your compost heap.
  3. Some of the tuberous roots may have become detached from the main body – this is okay. The loose tubers can either be disposed of or you can store them with the rest of the dahlia to see if they might make a viable plant the following summer.
  4. Dead tubers appear withered and wrinkled. These also need removing and can go on the compost heap.
  5. 'Do not clean the tubers under a tap; to get water on a tuber at this time of year often spells disaster. Turn the tubers upside down in a crate and leave to dry for a couple of weeks,' advises plantswoman and dahlia expert Sarah Raven in her blog.
  6. Next, label your tubers, recommends Megan Foster, category manager of bulbs & perennials at American Meadows . 'As you build your collection of varieties, you will want to remember which is which come planting time in the spring. Use a marker or tie on a label with old twist ties.'
  7. Once the tubers have dried out sufficiently, it is time to store them for the winter. There are several methods for storing dahlias. The best method for how to overwinter dahlias primarily depends on where you a storing them. If you are storing them in a slightly moist environment opt for paper bags or cardboard boxes as these will absorb the moisture from the air. If you are storing them in somewhere that is drier, then a plastic box or bin bag is a better option as these can be occasionally spritzed with water.
  8. Unlike bulbs they also need to be insulated to keep them warm and prevent them from drying out. You can either cover them in loose, dry compost, sand, vermiculite or straw, or you can wrap each tuber in newspaper. 
  9. Place your tubers in a dry and cool place – unheated greenhouses, sheds, porches or the cellar are all great options. 
  10. Check on your tubers throughout winter looking for signs of rot or severe dehydration. If you spot signs of rot, cut away the compromised material until you are back to the healthy tuberous material. It is also worth moving your dahlias to a drier location to prevent further rot from taking hold. 
  11. Dehydrated tubers are the other challenge when learning how to overwinter dahlias. It is quite easy to tell if your dahlias are dehydrated as they will look shrivelled. If this is the case, occasionally spritz the dahlias with water to help them absorb more moisture.

(Image credit: Getty Images)

Should I split my dahlia tubers before overwintering?

Whether you split your dahlia all comes down to a matter of confidence and knowledge about how to overwinter dahlias. 'If you’re not sure where the eyes are, don’t break apart your tuber clump in the fall before storage. The tuberous fingers of the dahlia are winter sugar and moisture survival supplies for the eyes which are the source of new growth for next spring. If you disconnect the two accidentally, you’ll be disappointed with lack of growth,' advises Megan Foster, category manager bulbs & perennials at American Meadows .

However, if you are certain where the eyes are and that they are still connected to plenty of tuberous fingers, then you can separate the two before overwintering. To do this use a clean knife to cut away the eye and tuber. Then overwinter in the same way you would a non-separated dahlia.

(Image credit: Getty Images)

Can you leave dahlias in the ground?

If you live in an area that have milder winters and very free-draining soil then you can leave your dahlia tubers in the ground. However, this is only suggested for hardiness zones 7 to 10. If you are leaving your tubers in the ground, then there are some steps you must follow to protect them during the cooler months. 

Once your dahlia has succumbed to the frost, leave it for about two weeks to let the sugars go back into the tuber, then cut the stem back to around 6 inches tall. Dispose of the foliage on your compost heap. After this, cover with a mound of deep mulch to insulate the tubers throughout the winter months.  

(Image credit: Getty Images)

Can you leave dahlias in pots over winter?

Although dahlias aren't candidates for the best winter plants for pots and borders, yes, you can leave dahlias in pots over winter. One of the beauties of growing dahlias in a pot is the flexibility that it offers. When in bloom, you are able to move your plants around your garden so that the most show-stopping displays are always front and center. 

This flexibility continues when figuring out how to overwinter dahlias that you have grown in pots. When overwintering pot grown dahlias, it is vital that they are sufficiently protected from the cold weather. 'It is important to create storage conditions that somewhat mimic dahlia tuber’s natural habitat under earth in a drier climate and non freezing latitudes,' advises Megan Foster. 

If you can move your pots inside, into a cool but frost-free, dark and dry place – like a garage, unheated greenhouse or shed – then do so. If you do not have a space to move your pots to, then cover with a mound of compost or manure, as you would with dahlias left in the ground. You can then cover your pot with frost-fleece to help protect it and move it to an area where it will be protected from rainfall.

Allow the pot to partially dry out. It is important to not let them dry out completely, but equally don't water regularly as you would during the growing period. Water as frequently as you would a cactus – a cup of water every month or so is sufficient. 

(Image credit: Getty Images)

How to overwinter dahlias in Saran wrap

Overwintering dahlias in Saran wrap is a fairly new method for overwintering dahlias, however, it has received a great response. In fact, it is now the go-to method for the American Dahlia Society, having moved away from vermiculite and plastic bags.

Start by lifting your dahlias, as you would for any other method, and clear them of soil. Whether you treat your dahlias with an anti-fungal treatment to ward off rot is a personal choice, and should you not wish to, you can simply skip this step. However, it will offer greater protection for your dahlias over the colder months.  

'Add a very small amount (around a tablespoon) of powdered sulfur to 3 cups of dry vermiculite in a gallon size ZipLock bag and mix thoroughly' suggests Marian Mandella, Bernard Mandella, and Richard W. Peters, M.D, experts at The American Dahlias Society . Then add your tuber and shake lightly so that your dahlia tuber is coated – 'a very, very light coating should be best.' 

Having done this, set your dahlias aside in a crate to dry overnight before wrapping. 'Tear off a sheet of plastic wrap about 20 or more inches long and lay it flat on a level surface. Place a tuber on one end and roll the plastic wrap over one complete turn. Lay another along side and roll again. Be certain that no tuber is touching another; plastic wrap must separate all tubers.' Once you've wrapped your dahlias, fasten with masking tape and label with the dahlias's name before storing in a dark and dry place at around 40°F for winter.

(Image credit: Getty Images)

What month do you cut back dahlias?

Cut back dahlias in late fall – October and November, however don't cut them back immediately. 'Leave the stems to go black from the first frost for approximately a two weeks to allow the sugars to go back down the stems to feed the tuber. Then cut the stems off just below ground level,' advises PL gardening expert Leigh Clapp.

You need to do this however you are overwintering your dahlia tubers as it will increase their likelihood of survival and the extra energy it provides will help them to restart growing in the following spring. 

(Image credit: Getty Images)

Having graduated with a first class degree in English Literature four years ago, Holly started her career as a features writer and sub-editor at Period Living magazine, Homes & Gardens' sister title. Working on Period Living brought with it insight into the complexities of owning and caring for period homes, from interior decorating through to choosing the right windows and the challenges of extending. This has led to a passion for traditional interiors, particularly the country-look. Writing for the Homes & Gardens website as a content editor, alongside regular features for Period Living and Country Homes & Interiors magazines, has enabled her to broaden her writing to incorporate her interests in gardening, wildlife and nature. 

How to keep dahlias in a pot from autumn to spring

09/29/2020

This way to keep dahlias in a pot from autumn to spring is suitable for annual undersized plants.

I decided to save the 'Figaro' dahlia that I cherished and nurtured by planting it with seeds in the spring. And since you can keep begonias in a pot, why not try to keep dahlias in the same way.

Dahlia tubers can also be preserved in the usual way by digging immediately after the first frost. But I wanted to prolong the flowering at home, so I chose a different way of overexposure of the plant in a pot.

Dahlia 'Figaro' is a small, potted plant with beautiful double bright red flowers. Due to the cold cloudy summer, the plant did not give full expressive flowering.

I understood that night frosts and cold matinees were about to come, and I would have to dig up bushes, cut stems, without waiting for numerous flowers.

Then the decision came to keep the flowers at home and, if possible, to admire the flowers, and then put the dahlia for winter storage.

There may be something similar on the Internet, but I am writing an article based on my own experience.

Potted flowers can be preserved, for example, by placing them in garden-like soil. In this case, you need to cut off the tops of the stems.

My goal was to have the dahlia bloom for some time at home. Therefore, I dug up the bushes without waiting for frost. I freed the roots (tubers) from the soil, washed them so as not to inadvertently grab earthworms, and brought them home.

I allocated a pot for each flower (ordinary plastic ones, you can use any opaque buckets for mayonnaise, salads), filled it with earth and planted it like an ordinary houseplant.

I did not plant one bush in the ground, but lowered the roots into a vase filled with swollen hydrogel. I did it on purpose so that the flower could decorate the room for a while, like a bouquet in a vase. When the buds faded, I transplanted the dahlia from the vase into the ground into a pot, cutting the tops of the stem a little.

The flowers are doing great, they have released the last buds, which I have already cut. Plants are slowly preparing for winter dormancy.

In the future, the leaves will wither and fall off, which means it's time to reduce watering and stop feeding. I cut off the extra stems, and then wrapped each plant pot in thick paper. Flowers removed in a cool place in the bathroom. But for example, it is possible under a wardrobe or a bed.

During the winter the soil was lightly sprayed from above. In February, I removed the excess soil from the tubers so that light fell on them. Moved the pots to the windowsill. And in early March, the first green sprout appeared.

Cared for like a houseplant. Before being taken out to the garden, dahlias in a pot must be hardened. For example, I took them to a cold greenhouse for additional shelter.

Keeping the dahlias in the pot proved to be an easy task. True, you can’t put a lot of pots at home. Therefore, I collect the seeds of an annual dahlia in the fall and sow them in early spring in a cold greenhouse.

Growing dahlias in pots - Gardening World

10/30/2020

Do you like container gardens? Then try growing dahlias in pots. Of course, planting an annual dahlia in a flowerpot or other container is no different than planting it in a flower garden. But this post is about perennial tuberous dahlias in containers.

It can be difficult to choose the right place for dahlias. After all, they need a lot of land, and for full flowering, fertile soil is needed, prepared in advance in the fall. Planting dahlias in pots is a good way to make it easier for yourself to grow them and to occupy (beautify!) a piece of land that is not suitable for cultivation.

In order for dahlias in flowerpots to look beautiful and organically fit into the landscape of your site, choose plants that are not too tall, up to 80 cm in height.

Together with dahlias in tightness, but not offended, canna (almost the only tuberous flower that endures tightness), pelargonium, petunia and other annual flowers and plants coexist well.

Growing dahlias in pots

Basic planting rules

Do not plant dahlias in too large nests, divide them. Each nest must have a root collar, otherwise the plant will never germinate. All thin root hairs should be trimmed. Think about how many tubers you want to plant at once - this will affect further flowering.

Select planting material healthy and without decay. A spoiled tuber does not have to be thrown away! Cut off the affected area, sprinkle with ashes or cover with brilliant green and plant. Keep an eye on this plant - it will need more nutrition.

Not all tubers can be viable and in order not to form voids in a large flowerpot, it is better to plant them in small peat pots or cardboard juice boxes, or ordinary plastic bags in March-April. And approximately, in May, transfer together with a clod of earth into large containers. This planting will give another plus: early flowering.

When planting in a box, do not forget about drainage holes and do not bury the dahlia too much, it is enough to cover the neck of the tuber with dry soil 5-6 cm.

Place plantings on a bright window. At the first time of growth at home, keep an eye on the temperature, 12-15 ° C and do not overmoisten the ground.

Choosing a pot and soil

Choose the size of large pots and flowerpots based on this recommendation: one dahlia bush needs at least 20-25 cm in circumference. And the minimum height of the pot should be 35-40 cm.

To avoid damage to the plant from strong winds, when planting in flowerpots, stick a small skewer nearby, indicating the location of the tuber, then you can, if necessary, install a support.

Mix potting soil with hydrogel to keep potting soil from drying out. If this is not possible, then water only when the top layer of soil dries up half the length of the index finger.

Buy potting soil or make your own: light and breathable. Dahlias, according to my observations, are not too picky in the choice of soil, but the best soil for them is sandy fertilized or, for example, garden soil with leaf humus; with neutral acidity pH 6-7. Pour large expanded clay or crushed stone at the bottom of the pot.

Care and watering

Remember that in the process of growth, the plant needs to be spudded a couple of times, that is, new earth must be added to the main stem, so fill the pot with soil ¾ to leave room to its top. At the end of August, hill up to a height of 10-12 cm. summer, remove the lower leaves that touch the ground.

When watering, once every 10 days, feed the flowers with a liquid complex fertilizer. For example, at the beginning of growth, nitrogen + phosphorus + potassium (with a predominance of nitrogen). Then, before flowering, potassium-phosphorus with the addition of trace elements for the brightness of the buds.

For container plantings, it is better to use "long-playing" fertilizers, such as "AVA".

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