Quick Answer
Yes, you can store dahlia tubers in the garage over winter. The ideal storage conditions for dahlia tubers are cool and dry, with temperatures between 40-50°F. The garage is often an ideal spot because it provides shelter from rain and cold while still getting chilly enough for the tubers to go dormant. Make sure to store the tubers in a cardboard box, paper bag, or mesh bag, and pack them with peat moss, vermiculite, or straw to prevent rotting. Check on them periodically over winter.
Storing Dahlia Tubers for Winter
Dahlias are tender perennials that cannot withstand freezing temperatures and will die back to the ground with the first fall frost. However, the tuberous roots can be dug up and stored over winter to be replanted again in spring.
Properly storing dahlia tubers over winter is crucial for their health and ability to reflower the following season. Here are some key tips for successful dahlia tuber storage:
When to Dig Up Tubers
– Dig up dahlia tubers after the first hard frost when the foliage has been blackened by cold temperatures. This is typically 4-6 weeks before your first expected frost date.
– Use a garden fork to carefully lift up the plant and access the tubers.
– Allow 1-2 weeks after digging for the tubers to dry and cure in a warm, dry spot. The skin will thicken to prevent rotting.
Storage Location
– Cool, dry spot with temperatures between 40-50°F. The garage is often perfect.
– Avoid anywhere that drops below freezing or gets excessively warm. Fluctuating temperatures can cause the tubers to sprout prematurely or rot.
Storage Containers
– Store in cardboard boxes, paper bags, mesh bags, or trays with separate compartments. Avoid plastic bags.
– Pack with peat moss, vermiculite, straw, or newspaper to cushion tubers and absorb moisture.
Inspection and Maintenance
– Check tubers 1-2 times over winter for signs of rotting. Discard any diseased or rotting tubers.
– Watch for shriveling, which indicates dehydration. Sprinkle with a bit of water if needed.
– Keep stored in the dark to prevent sprouting. Sprouting uses up energy reserves.
Why Store Dahlia Tubers
Dahlias are not reliably winter hardy in most climates. The lush, colorful flowers and foliage we enjoy will be killed off as soon as freezing weather arrives in fall. However, the tuberous roots can survive winter if dug up and stored properly.
Here are the main reasons to store dahlia tubers over winter:
– Allows you to replant the same varieties in spring instead of starting over from seed.
– Mature, good sized tubers produce more robust plants and flowers their second year.
– Tubers multiply each year, yielding more plants to spread around the garden.
– Can save money instead of buying new tubers each spring.
– Certain heirloom or hybrid varieties are difficult to find commercially.
– Avoids having to protect tubers in the ground over winter.
Storing tubers in the garage or an unheated basement provides cool, stable conditions for dormancy so gardeners can enjoy their favorite dahlia varieties for years to come.
Preparing Tubers for Storage
Follow these steps for successfully preparing and storing your dahlia tubers to ensure they make it through winter in good condition:
When and How to Dig
– Wait until 4-6 weeks after the first light frost when foliage is blackened.
– Carefully dig tubers using a garden fork, taking care not to pierce or slice them.
– Gently shake off excess soil but do not wash the tubers.
Curing
– Allow freshly dug tubers to cure for 7-10 days in a dark, warm (70°F) spot to thicken skins.
– Arrange tubers with some space between them in a single layer on newspaper.
– Turn occasionally to expose all sides to air circulation.
Inspect and Divide
– Inspect each tuber and discard any that are mushy, damaged, or diseased.
– Carefully divide any large clusters into individual tubers.
– Allow cuts to callous over 1-2 days before packing for storage.
Dry Packing Material
– Peat moss, vermiculite, straw, and shredded newspaper all work well.
– These materials cushion tubers and absorb excess moisture to prevent rotting.
Storage Containers
– Cardboard boxes, paper bags, mesh bags, burlap, or vented plastic bins. Avoid sealed plastic.
– Materials should allow air circulation but prevent freezing.
– Label containers with dahlia variety names if storing multiple kinds.
Ideal Storage Conditions
To keep dahlia tubers healthy in storage over winter, the ideal conditions are:
– Cool Temperatures: Ideal range is 40-50°F. Avoid freezing or overheating. Fluctuations in temperature can damage tubers.
– High Humidity: Between 85-90% relative humidity prevents shriveling or dehydration. Occasionally mist tubers if needed.
– Good Air Circulation: Some airflow prevents condensation and rot but avoid drafts directly on the tubers.
– Dark Conditions: Complete darkness prevents tubers from sprouting prematurely, which uses up energy reserves.
The garage is often a good spot because it meets many of these conditions in autumn and winter. An unheated basement also works well.
Temperature Regulation
Insulating the storage containers can help maintain a stable temperature. Opening garage doors briefly on sunny winter days can raise the temperature enough to prevent freezing. Space heaters or small heating pads can warm up the storage space if needed, but avoid allowing the area to get too hot.
Humidity Control
Packing tubers in moistened peat moss or vermiculite helps preserve humidity. Misting the packing material occasionally adds moisture if condensation is not visible inside the container. Keeping containers away from heat sources prevents excess drying.
Air Circulation
Storing tubers in breathable containers allows air movement while preventing drafts directly on the tubers. Stacking containers allows air circulation around and between them. Leaving space between tubers inside the container also improves airflow.
Caring for Tubers in Storage
Dahlia tubers require minimal but consistent care and monitoring while in storage over the winter months. Here are some tips for keeping them healthy:
– Inspect every 4-6 weeks for signs of rot, shriveling, or sprouting.
– Gently remove any diseased or rotting tubers and discard them promptly.
– If tubers are shriveling, give them a light misting of water.
– Keep storage containers in complete darkness.
– Maintain consistent cool temperatures around 40-50°F.
– Re-pack containers with fresh dry material if moisture levels get too high.
– Avoid allowing tubers to freeze or overheat at any point.
With attentive storage conditions, dahlia tubers can be kept dormant and in good health for planting again next spring.
What Not to Do
Just as important as providing proper storage conditions is avoiding certain mistakes that can damage tubers:
– Do not store in plastic bags or non-breathable containers.
– Avoid washing or getting tubers wet before storage.
– Do not remove all soil – some cushioning against other tubers helps.
– Prevent sprouting by keeping in dark. Do not store in light.
– Never allow tubers to freeze or be exposed to temperatures below 32°F.
– Don’t store near heat sources that cause overheating and sprouting.
– Avoid drastic temperature swings; keep storage area stable.
– Do not pile tubers tightly without spacing and packing material. Airflow is key.
– Do not store diseased or damaged tubers they will spread rot to healthy ones.
Following the right procedures for digging, curing, packing, and storage conditions minimizes losses.
Watch For Sprouting
One common issue with storing dahlia tubers is premature sprouting before they get replanted in spring. Here’s what to do if tubers start sprouting in storage:
– Gently twist off any small sprouts emerging from tubers.
– Double check storage area is completely dark and not too warm.
– If sprouting persists, move tubers to slightly cooler spot.
– Packing in fresh dry peat moss can help deter sprouting.
– If sprouts are longer, do not break them off. Gently plant the tubers.
– Heavily sprouted tubers can be planted in late winter if ground can be worked.
Though sprouting tubers may still grow okay, it’s best to plant them as soon as possible once active growth begins. Otherwise the sprouts use up energy reserved in the tuber that is needed for flowering.
Conclusion
Storing dahlia tubers over winter allows gardeners to enjoy the same plants and flower colors year after year. With proper harvesting, curing, packing, and storage conditions, tubers can go dormant from fall to spring. A cool, dark garage or basement provides an ideal spot for winter storage. Just be sure tubers do not freeze, overheat, or dry out. With a little care, stored dahlia tubers will reward you with a bountiful, vibrant flower display when replanted next season.