Starting Cannas, Dahlias, Caladiums and other Non Hardy Bulbs Indoors
Retrieve the rhizomes, tubers or corms (we’re calling bulbs) that you may have stored for winter or received from a friend. Or purchase new bulbs from your favorite garden center, catalogue or on-line source.
Make sure the bulbs are firm and pest free. Discard any soft, discolored or pest-infested bulbs now.
This is also the perfect time to divide large clumps that grew and multiplied last season. Be sure to leave several growing points, often called eyes, on each division.
Next fill a flat, or pot with a well-drained potting mix. Lay the rhizomes of cannas and tuberous roots of dahlias on their side. Corms and tuberous stems are set flat with the root plate facing down.
Once you’re done planting, move the transplants to a warm sunny location and water thoroughly as needed. Fertilize once the leaves appear and be sure to harden off the plants before moving them outdoors.
A bit more information: Wait for the soil to warm to plant gladiolus corms directly outdoors in the garden. Plant large gladiolus corms 4 to 6 inches deep and smaller ones 3 inches deep and 6 inches apart. Most glads bloom in 8 to 10 weeks after planting. Extend the bloom time throughout the summer by making successive plantings at 2 week intervals. Stop planting about 12 weeks before the average date of the first fall frost.