Dahlias, known for their great variety of blooms, long growing season and pleasant ease of care, are commonly believed to be perennials in various locations around the world. For areas with the coldest winters, the dahlia is, unfortunately, an annual plant that needs replanting every season. The harsh winter climate freezes the dahlia tubers, killing the plant in the coldest environments. If you prefer to keep dahlias year after year, you should overwinter the tubers indoors or in a sheltered location.
Steps
Method 1 of 2: Extract the Dahlia Bulbs from the Ground
Step 1. Check the stems and leaves of your dahlia
In order for your dahlias to overwinter properly, you will need to unearth them at the right time. Check for dahlias regularly; when the stems and leaves turn black you can extract them.
This generally occurs a couple of weeks after the first frost
Step 2. Cut the plants
Taking the dahlias out of the ground after the first frost allows the plant to use its stems to feed the tubers for the next season. Absorption of nutrients is necessary for the plant to have a good chance of surviving the winter.
Once the leaves and stems have turned completely black, cut them back a few inches above the ground, leaving only the main stems
Step 3. Pull the dahlia out of the ground
Dig a circular hole more than 30cm away from the plant stem to begin the process. Use a forked shovel to lift the plant off the ground, rather than pulling the stem. Pulling the stem could damage the tubers.
Step 4. Carefully remove loose earth
Once the tuber is out of the ground, remove all loose earth and debris without using force; the tubers of the plant are very delicate. Avoid damaging or breaking the tubers when you shake off the earth.
You can also rinse off the earth with water if you are concerned about breaking or damaging the tubers
Step 5. Dry the tubers
Once they are clean, hang them to dry in a covered area. Be sure to hang these tubers upside down to aid in proper drying.
You can hang the tubers to dry in a shed, garage, or any other cool, dry environment
Method 2 of 2: Storing the Dahlia Bulbs
Step 1. Place the tubers in baskets
When dry, place the tubers and stem in baskets and cover them with dry material. This dry material could include:
- Sand
- Newspaper strips
- Peat
Step 2. Check the dahlias regularly for signs of rot
Cover the plants and check them every couple of weeks for any signs of black or colorless growth. This growth could indicate rot. A flabby, soft plant is dehydrated.
- If your plant is dehydrated, mist the tubers with water until they are slightly moist.
- If you find rotten or damaged parts on the plant, remove them to give the rest of the tuber a better chance of recovery.
Step 3. Divide the dahlias
A few weeks before the last frost, move the tubers to a new location. Now is the time to divide the larger tubers, so as to give the new cuts a better chance of resisting mold, rot and fungus.
Remove the shoots and leave a single large one in each section
Step 4. Replant the dahlias in a pot with fresh soil
Place each tuber of dahlia in a pot with fresh soil and fertilizer. Store the plant in an area out of direct sunlight. Once the leaves have formed and hardened, you can move the plant in direct sunlight or put it back in its original position before winter.
