Bulbs Over Winter
Q. What is the best way to dig up, clean and store gladiolus and dahlias? What are the little white sacs on glad bulbs?
A. Gladiolus corms and dahlia tubers are generally dug up after the first frost or before Halloween. Cut off all the stems and foliage, let the plants dry, and shake off all the soil. Make sure each corm and tuber is firm and not rotted. Place them in a box or tray and cover with peat moss. If you know the cultivar name, tag the plant.
Store them in a dark, cool place, checking them over winter. If the dahlia tubers are shriveled, sprinkle a little water on them. Dahlias can be potted up in spring for an early start in the garden.
"The white sacs you see attached to the gladiolus corms are little bulblets. You can remove them or not. If left on the corm, they will grow larger, and may enhance the number of stems on the plant. If you remove them and plant them, it will take at least three years before they flower," explains Joni Cotton, perennial manager, Hawthorn Gardens, Hawthorn Woods. Back to top
Q. I purchased some pre-chilled hyacinths and tulips for forcing
but there were no directions with them. Does this mean I don't have to chill them in the refrigerator, and will they just bloom in the house any time during the winter? The
last batch of bulbs became moldy
in the refrigerator.
A. Using pre-chilled bulbs avoids the 12- to 14- week cold treatment that bulbs need for indoor blooming. However, you need to pot up the bulbs in a loose potting mix. Do not cover the bulbs in plastic wrap or paper bags. It will still take 3 or 4 weeks of cold for roots to appear.
Hyacinths kept cool do not need to be potted. They can sprout roots in a saucer of water with the bulb held in place by stones. Check the water level and make sure it just touches the base of the bulb and add water as needed.
The bulbs can be forced as soon as you see roots, or you can hold them in the cold temperature to space out the bud development. Place rooted bulbs in bright light in a cool room, and watch for buds. Rotate the plant so the flowering stem will be erect. "Your previous bulbs rotted because they were not potted up," says Lori Harms, greenhouse manager, Countryside Nursery, Crystal Lake. Back to top
Q. I plan on saving my amaryllis bulbs that I kept outside over summer, but I noticed red streaks on the inner side of the leaves. What caused that? Will I be able to save my bulbs?
A. There are several possible causes of red streaks in amaryllis hybrids (Hippeastrum), explains Bill Welter, owner of Victor Hlavacek Florist, Winnetka. If the streaks occur on the foliage only, excess moisture and not enough air around the bulb could have caused the streaks. Amaryllis is also susceptible to leaf scorch, which can cause red streaks on the foliage and on the bulb. This was common on older varieties.
You can save the bulb for next season by letting the leaves die down, then trimming off the foliage, and dipping the bulb in a fungicide solution. Another possible reason for leaf scorch is tobacco mosaic disease, transmitted by insects. Back to top
Q. Is there a best time to plant tulips? I see them at the garden centers in late summer but I am afraid that it is too early to plant them. If I wait too long, I might forget all about them.
A. Fall bulb planting should wait until soil temperatures drop to 55 degrees or cooler. This usually occurs when nighttime temperatures drop to 50 degrees or lower for two weeks or more. While waiting to plant, store the tulips in a cool, dark place away from direct sunlight--but don't forget them. After planting, water the bulbs well, advises the Netherlands Flower Bulb Information Center.
If you plant grape hyacinth bulbs amidst your tulips, they will come up early in the fall and serve to mark the position of your tulips. Back to top