Dormant dahlia tubers don’t look like much. But as long as you start with healthy tubers and provide the proper care, these funny-looking potatoes will turn into robust plants covered with the beautiful flowers we love.
While each healthy tuber should have an eye that will sprout into a plant, it’s sometimes difficult to spot these tiny eyes, let alone know if they’re viable. Waking up your dahlias encourages the eyes to sprout and lets you know that they are worth planting. It also helps you jump-start the growing season and allows you to take cuttings.
Not sure how to wake up dahlia tubers? No problem! I’ll cover when and how to complete this process at home.
Dahlias are beloved for their showy, colorful blooms that light up gardens from midsummer into fall To get the most flowers from your dahlias, it’s important to properly wake up the tubers in spring
Dahlia tubers are the storage organs that the plants use to survive winter. In spring, they must be coaxed to wake up from dormancy and begin actively growing again. Waking up dahlia tubers properly gives them the best start to the growing season and results in stronger more vigorous plants with abundant blooms.
Here is a complete guide to pre-sprouting dahlia tubers for healthier plants and maximum flowers.
Why Pre-Sprout Dahlia Tubers?
Pre-sprouting tubers indoors gives them a head start on the season. It allows the small new shoots to establish before being planted outdoors. This minimizes transplant shock and results in stronger, more vigorous plants.
If tubers are planted outside too early while soil is still cold and wet, the sprouts may rot or fail to thrive. Pre-sprouting for 3-4 weeks indoors avoids this issue.
When to Start Waking Up Tubers
Time your pre-sprouting to occur 4-6 weeks before your average last spring frost date. This gives outdoor soil time to warm up before sprouted tubers are planted.
For most regions, mid to late April is ideal. If you start too early, the young sprouts may grow spindly and weak before they can be planted out.
Aim to have sprouted tubers ready to plant around early to mid May in all but the warmest climates. Check your specific frost date to schedule perfectly.
Step-by-Step Guide to Pre-Sprouting Dahlias
Follow these steps for waking resting dahlia tubers and getting them primed for planting:
1. Retrieve Tubers from Storage
Carefully remove tubers from their winter storage containers. Avoid damaging any small sprouts that may have already begun growing. Remove any rotted or desiccated tubers that won’t be viable.
2. Place in Trays
Arrange tubers together in trays, bins, or pots with drainage holes. Plastic seedling trays or aluminum roasting pans work well. Partially cover with moist vermiculite, potting mix, wood shavings, etc.
3. Provide Warmth and Light
Place containers in a warm, sunny spot indoors like a south window. A greenhouse or cold frame also works if protected from frost at night. Ambient temperatures around 70°F are ideal.
4. Keep Moist
Check moisture levels daily. Damp but not soggy soil is needed. Mist or water lightly when the sprouting medium becomes dry. Avoid having tubers sit in overly wet conditions.
5. Watch for Sprouts
Check for small pinkish sprouts emerging at the tuber necks in 1-3 weeks. Some varieties take longer – don’t discard any firm tubers too soon. Once sprouted, ensure they get bright light to avoid leggy growth.
6. Hold Off Planting Out
Let sprouts grow to 2-3 inches before moving outdoors. Time planting for roughly 4 weeks after starting waking process. Wait until nighttime temperatures are above 50°F.
What to Expect When Waking Dahlias
Here’s what to look for as your dahlia tubers emerge from dormancy:
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Small pinkish/red sprouts form at the tuber necks around 1-2 weeks into pre-sprouting. This is where the stems will grow from.
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Most varieties will show sprouts in 2-3 weeks. Some take longer – up to 4 weeks. Discard any mushy tubers.
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Let sprouts grow to about 2-3 inches tall before planting out. Avoid leggy, weak growth by providing sun.
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Tiny white nodules on the tuber are new roots beginning to form. This is a great sign of an active, healthy tuber.
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Leaves will not form until plants are up and growing in garden soil. Do not wait for leaves to transplant.
Troubleshooting Problems
No sprouts forming:
Be patient – some tubers take 4 weeks or longer. Discard any softened or rotting tubers. Ensure temperature is at least 65°F.
Tips die back:
Likely caused by cold damage if tubers got chilled. Cut back to healthy growth and replant. Avoid frost risk.
Leggy, weak sprouts:
Insufficient sunlight during waking period. Move to brightest spot or under grow lights to strengthen growth.
Moldy tubers:
Excess moisture – reduce watering and provide good airflow. Dry out sprouting medium and discard any rotted tubers.
Key Tips for Success
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Start waking 4-6 weeks before outdoor planting time.
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Provide bright light once sprouts emerge to prevent lanky growth.
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Time outdoor planting for after danger of frost when soil warms above 60°F.
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Take care not to overwater during pre-sprouting phase. Damp but not wet soil.
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Gently plant pre-sprouted tubers outdoors with sprouts facing upward. Avoid disturbing the emerging roots.
Waking up dahlia tubers properly gives them the best start to the growing season. Follow these guidelines for pre-sprouting your tubers and you’ll be rewarded with vigorous, floriferous dahlia plants this summer.
Frequently Asked Questions
How long does it take to wake up a dahlia tuber?
It typically takes 1-3 weeks for dahlia tubers to wake up and begin sprouting. Check them daily and watch for small pinkish sprouts emerging from the necks. Discard any soft or mushy tubers.
How to get dahlia tubers to sprout?
To get dahlia tubers to sprout, place them in a warm spot indoors around 70°F. Keep the sprouting medium lightly moist but not soggy. After 1-3 weeks, sprouts should emerge and can be planted out after last frost when soil is 60°+ degrees.
How to activate dahlia tubers?
To activate dormant dahlia tubers, first soak them in a bucket of tepid water for an hour to fully rehydrate. Then place tubers in a warm spot around 70°F with lightly moist medium. Sprouts will emerge in 1-3 weeks when tubers activate.
How to wake up dahlia tubers in ziploc bags?
You can wake up dahlia tubers in ziploc bags by putting them in a bag with a bit of moist potting soil. Seal the bag loosely and place on top of a warm spot like a refrigerator where heat radiates. Check moisture and sprouts should form within a few weeks.
Can you revive dahlia tubers?
It is possible to revive dahlia tubers by soaking in tepid water for an hour, then placing in warm, humid conditions around 70°F. Watch for sprouts emerging from the neck in 1-3 weeks. Discard any mushy or rotten tubers that fail to revive.
How should I care for dahlia tubers?
Caring for dahlia tubers involves proper harvest and storage, keeping them in a cool dry place over winter. In spring, wake them up by soaking and placing in warm, humid conditions to sprout before planting in rich soil after all frost danger has passed.
When should you plant dahlia tubers?
For most regions, dahlia tubers should be planted in late spring or early summer after the last expected frost when soil temperatures reach at least 60°F. Allow them to pre-sprout indoors for 3-4 weeks prior to planting outdoors.
How should dahlia tubers be stored?
Dahlia tubers should be stored in a cool, dry location around 40-50°F over the winter. A basement, unheated garage, or refrigerator works well. Pack in vermiculite, sawdust, or wood shavings to prevent rotting. Check periodically for shriveling or mold.
How do you grow a dahlia plant from a tuber?
To grow dahlias from tubers, first wake them up by soaking and keeping warm and humid indoors until sprouts emerge. Plant sprouted tubers outside in rich soil after all frost danger has passed. Bury neck and sprouts facing up. Water when dry and fertilize throughout summer.
Following proper techniques for waking up and pre-sprouting dahlia tubers will get your plants off to a vigorous start. With good care, you’ll be rewarded with an abundant harvest of gorgeous dahlia blooms in your summer garden.
Taking Cuttings From Dahlia Tubers
Most growers plant dahlias directly in the ground. However, you can also wake up your dahlia tubers earlier in the year and take cuttings of the resulting sprouts. Propagating dahlias using this method allows you to get multiple plants from a single tuber and enjoy flowers earlier in the year.
If you want to take dahlia cuttings, you should wake up your tubers earlier in the year. Starting the process in January or February gives them plenty of time to sprout and allows you to pot up cuttings before they head outdoors.
When to Wake Up Dahlia Tubers
You should begin waking up your dahlia tubers four to six weeks before you plan to plant them outdoors. The ideal planting time varies depending on where you live, but you can use your last spring frost date and the soil temperature as guides.
Dahlias can’t tolerate cold, so wait until after your last spring frost to plant them outdoors. Waiting until the soil warms up to 60°F (16°C) will limit plants’ stress during the transition from their cozy indoor environment to the outdoors. Warm soil will also support the plant’s growth.