Dahlias are absolutely stunning flowers that can add a pop of color to any garden. Their vibrant blooms come in a wide range of colors shapes and sizes. Many gardeners choose to grow dahlias in pots so they can move them around the yard and even bring them indoors over winter. But how long can you actually leave dahlias in pots during the colder months? Here is a complete guide to overwintering dahlias in pots successfully.
Why Overwintering Dahlias is Important
Dahlias are not cold hardy plants Exposing them to freezing temperatures and frost can damage or even kill them Their above ground foliage dies back with the first fall frost. But the tubers below ground need special care to survive winter.
Overwintering dahlias properly allows them to go dormant. This gives the tubers time to rest and recharge for the next growing season. Then your flowers will return bigger and more beautiful than ever the following spring and summer.
When to Bring Dahlias Indoors
Timing is crucial when overwintering dahlias in pots. You need to bring them inside before the first hard frost in your area, which is around late October or early November for most regions. Some key signs it’s time include:
- Leaves starting to yellow and die back
- No new blooms forming
- Overnight temperatures dipping below 40°F
Waiting too long risks the tubers being damaged But bringing them in too early can disrupt the plants’ normal cycle and lead to weakly growth,
How Long Can Dahlias Stay in Pots Over Winter?
Most dahlias can remain in pots for winter storage for around 5 months. The ideal indoor storage time is from November through March. However, the length depends on several factors:
- Your climate – Shorter storage time needed in colder climates
- Pot size – Bigger pots hold moisture longer
- Storage conditions – Warmer and more humid allows longer storage
- Tuber health – Weakened tubers won’t store as long
In areas with milder winters, you may be able to store them 1-2 months longer. But in harsh climates, err on the side of less time to prevent rotting. Monitor pots regularly and remove any mushy or molding tubers.
Preparing Dahlias for Winter Storage
Follow these tips to prep dahlias in pots for storage:
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Cut stems back to 4-6 inches above the soil
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Remove all dead flowers and foliage
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Check pots for cracks and proper drainage
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Inspect tubers for disease or damage
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Allow pots to slightly dry out for 3-7 days
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Provide humidity – set pots on pebbles with water below
Keeping soil slightly dry prevents tuber rot over winter. Inspecting thoroughly removes any pests or diseases lying dormant. And cutting back stems and dead material removes places mold can start.
Best Places to Store Dahlias in Pots
Dahlias need a dark area that maintains temperatures between 40-50°F during storage. Some good options include:
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Unheated basement or garage
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Crawl space or cold cellar
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Insulated shed or greenhouse
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Cool spare room indoors
The spot should be dark to keep the tubers dormant. Make sure pots aren’t sitting directly on cold concrete floors. Place on wood planks or pallets to insulate.
Caring for Stored Dahlia Pots
Dahlias in pots need a bit of care while in storage:
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Provide humidity – Group pots together or set on pebbles in water
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Check soil moisture monthly – Tubers should never dry out fully
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Water very sparingly when needed
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Monitor for mold, rotting, shriveling, or pests
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Remove any damaged tubers immediately
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Keep storage area completely dark
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Ensure consistent 40-50°F temperatures
Don’t let pots fully dry out or tubers can shrivel. But only water slightly to prevent rotting. High humidity also helps maintain tuber plumpness.
When to Bring Dahlias Out of Storage
Start transitioning stored dahlias back to normal care in early spring after the threat of frost has passed. This is usually late March or April. Move pots back into sunlight and warmer temperatures gradually over 2-3 weeks. Water more as growth starts and new shoots appear. Repot into fresh soil once sprouted. Hold off planting outside until nighttime temperatures are above 50°F. With this process, tubers should start actively growing again by mid-spring.
Common Mistakes to Avoid
Here are some key mistakes to avoid when overwintering dahlias in pots:
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Leaving pots exposed to frost and freezing
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Allowing pots to completely dry out while in storage
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Storing tubers in overly wet soil that causes rotting
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Storing in temperatures consistently below 40°F or fluctuating wildly
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Keeping in too warm of temperatures over 60°F that prevents dormancy
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Storing in a humid area prone to mold growth
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Failing to inspect pots and remove any diseased or damaged tubers
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Letting pots freeze or overheat when bringing back outside
Following proper timing, storage conditions, and care methods will set your dahlias up for success. Just avoid these common pitfalls, and your flowers should thrive year after year.
Storing Dahlias Indoors in Pots Allows Season After Season of Beauty
While dahlias need a bit of special care over winter, with the right approach you can easily keep tubers alive from season to season. Storing pots in a cool dark spot for 4-5 months prevents damage from cold and allows proper dormancy. Monitoring soil moisture and humidity while providing stable temperatures gives tubers the best chance at re-sprouting in spring.
Just remember to transition plants slowly back into sunlight and warmer conditions next growing season. With a little diligence over winter, your dahlias will return healthier than ever. So you can enjoy their vibrant colors in your garden pots year after year.
When to dig up dahlias (if you’re going to)
Most people wait for the first frost. Your dahlia foliage will blacken and wither. But one frost isn’t likely to kill the tubers.
See this advice if you do need to lift and store your dahlias in winter.
And you can always treat dahlias as annuals, as many people who live in colder climates do. There is nothing wrong with buying your dahlias from new every year, and it gives you the option to change the colour scheme. One plant will cost you less than a bunch of flowers and will give you months of blooms.
How to winterize dahlias in the ground
Firstly cut away the dead and dying foliage. I find some of my dahlia stems are so thick, they need loppers not just secateurs. (I particularly like Wilkinsons Ultralight Loppers, because they really are so light.)
Note: links to Amazon in this post are affiliate links, which means I may get a fee if you buy through them, but it won’t affect the price you pay. I’ve only linked to products I’ve tried myself and liked.
Once you’ve taken away all the vegetation, cover the dahlia with as big a mound of compost or mulch as you can. Pile it on, making sure that the stems are well covered to protect the snow and rain getting in down the hollow parts.
Then add a stick to show you’ve got a dahlia there. It’s as simple as that.
Overwinter Dahlias in Pots | The Easiest Way To Store Them Over Winter!
FAQ
Can potted dahlias be left in pots over winter?
Potted Dahlias
Here’s how to overwinter dahlias that are grown in pots: Cut back the entire plant to 4 – 6 inches. Keep the dahlias in their pot over winter. Keep the pot in a cool, dry, dark place that doesn’t freeze.
What to do with dahlias in pots in winter?
Yes, you can leave your dahlias in pots over the winter but you will need to make sure they are protected from the cold. Cut back your plants, relocate your pots to a frost-free garage or shed for the winter and allow the compost to dry out completely.
How long do dahlias live in pots?
Dahlias require full sun to thrive. In very hot, sunny climates, consider planting them in a spot with a little afternoon shade to protect them from excessive heat. How long do potted dahlias last? If the tubers are properly overwintered, they can last a couple of seasons or more.
How far down do you cut dahlias for the winter?
(In warm climates, some growers leave their tubers in the ground and lift and divide in spring.) Here’s how to lift your tubers. After a killing frost or about 7-14 days before you want to lift your tubers, cut the plant down to about 6 inches.
Should dahlias be left in pots for winter?
Dahlias are not fully hardy plants, meaning their tubers can be damaged by consistently freezing temperatures and wet soil. However, there are advantages to leaving tubers in pots for winter: Avoid digging up and disturbing the roots. Pots provide insulation and drainage compared to garden beds. Easier to move pots to protected areas as needed.
How do you keep a dahlia plant alive in winter?
Cut back the entire plant to 4 – 6 inches. Keep the dahlias in their pot over winter. Keep the pot in a cool, dry, dark place that doesn’t freeze. Don’t water it, just let it stay dry. Prepare a paper bag by adding some very light moist peat moss to a paper bag. Cut back the entire dahlia plant to 4 – 6 inches.
How to overwinter dahlias?
Here are some key points to keep in mind when overwintering your dahlias: 1. Start by selecting the right pot. Dahlias need plenty of space to grow, so make sure the pot you choose is large enough! If you’re planning on growing more than one dahlia in a pot, make sure the size of each pot is equal. 2. Make sure the pot is well-drained.
How do you acclimate dahlias to winter?
Begin transitioning pots back outdoors in early spring. In early spring, acclimate potted dahlias to active growth once again: Move pots to a sunny, protected spot outdoors during the daytime. Bring pots back into shelter overnight until risk of frost is gone. Remove excess winter mulch from pots to encourage new growth.
Can dahlias survive winter?
Dahlia tubers will not survive winter in extremely cold climates if they are left in the ground. The tubers will rot if the soil is too wet, and they cannot tolerate heavy frost. It is a better idea to dig up the tubers that are in the ground, clean them off, and store them in a dry place until spring. Do you cut dahlias back for the winter?
Will winter kill dahlia tubers?
Although the cold frosts of winter may kill your dahlia tubers, you don’t want to move your pots inside the house, either. They don’t like to be too hot, and they especially don’t like the ever-changing humidity levels as the dampness of winter merges with the dryness of your central heating system.