Bulbs - Dahlia
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  (May) I have a large clump of Dahlia's that I recently bought at a nursery. They are about 8 inches tall -- still potted, but look ready to start budding and blooming. May I break this plant apart since it obviously has several tubers and replant each one now? I understand that it will set back the blooming by several weeks which is OK with me since I have about 10 more plants which are growing from bulbs. They are in size and maturity well behind the potted plant that I bought. Obviously I do not want to kill the potted plant which was much more expensive than the bulbs. The problem is that I planted 16 Dahlia along my driveway from bulbs and some of the bulbs rotted. I only have ten living plants. I need to fill in blank spaces and I think that this is the easiest way if the potted Dahlia can be separated.

  Dividing them when they have flower buds set is not ideal. They will wilt for a while, and it will slow down their response time. I would prefer you simply buy some extra new dahlia plants, but if you want to match plant size with your existing plants, do the dividing ASAP. Be sure to keep the plants well watered while they make the transition. You will probably see a great deal of wilting while the plants regenerate roots and get acclimated.

  (September) I currently have in two pots on our front porch, both of which contain dahlias and geraniums. I would like to begin considering what to plant in the pots for fall/winter. Will you please offer suggestions of plants which are vibrant in color and can be seen from the street? My understanding is dahlias are perennials. Should I cut them back or how should they be treated in order that they will bloom next year?

  If you plan to replant these containers this fall, you may want to lift and store the dahlia bulbs for replanting next season. Dahlia’s are considered moderately winter hardy, but in containers it would probably be best to lift and store the dahlia bulbs for the winter season anyway. The soil in the containers gets much cooler, and could damage the dahlias. You can wait for a few weeks before planting winter color, but options include pansies, violas, flowering kale, Dianthus or dusty miller. While the individual flowers may not be stunning from the street, it should provide long season color. You might also consider planting some bulbs beneath the annual color for even more flowers in the spring.

  (October) We planted some dahlia "bulbs" last spring in our yard in Bella Vista. They grew up to 6 feet tall with lovely 6" blossoms. Should they be dug up and replanted in the spring, or mulched and left in the ground?

  I am jealous -- mine have never done so well! Dahlias have been surviving fairly well in central Arkansas, and further south, but they often don't perform as well in hot, humid climates. In Bella Vista, I wouldn't take a chance on winter survival. Dig them up and store them for the winter. How cold a winter we have would make a difference to their surviving outdoors even up there, but since you can't predict, don't take any chances.

  (December) Before the weather turned cold, the dwarf Dahlias that I planted this Spring and left in the ground, began growing again and grew to about 6" to 8" tall. Can they winter-over as is, or should they be dug and/or mulched?

  Dahlia bulbs (actually tuberous roots) have been quite winter hardy from the central part of the state south, the past ten years or so. The foliage is not hardy; they usually die back to the ground with a killing frost. I really don't know the status of your bulbs now, since they went dormant, and were regrowing with the odd weather we had. Since they had started growing again-using up stored food, I don't know how winter hardy they will be. At this point, there isn't much you can do but cut off the top foliage and mulch. I suppose you could lift and store and replant in the spring, but they would need to be kept cool. In any event, wait and see what happens next spring. I would hope the cold has put them into dormancy and there is still something left inside the bulb to begin growth again next spring.

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