|My Dalhia bulbs went crazy last fall with tons of flowers. I am no longer getting flowers and would like to dig up and separate and transplant the bulbs. However, I have lots of folage that is not dying back. They are holding their own and, in some cases, growing again. Should I just cut the stems off at ground level? How do I get these things to die back?|
|Dahlias grow easily in zones 4-10. In zones 8-10 you can leave the tubers in the ground over the winter (zone 8 with mulch), providing the planting bed has good drainage. In all other zones it is best to dig the tubers up before or just after the first mild frost. If your winter weather is mild, the dahlias may not go into dormancy without a little help from you. Cut back the foliage now, then dig and divide the tubers. Here are some general dahlia growing guideline:
After frost kills the foliage, dig the dahlia tubers, shake off excess soil, and store the tubers in peatmoss or sawdust. The tubers should look like the spokes of a wheel with the original stem in the center. Place the entire group on a layer of peat and place more peat around them. Store your dahlias in a cool, dark location where it remains above freezing during the winter months. In the spring you can divide the tubers. Look for a tiny bud (or eye) on the topmost part of the tuber, closest to the stem. As you cut each tuber away from the old, dried stem, make sure each tuber has a bud. When you're ready to plant, choose a site that gets sunshine all day, and dig a hole about one-foot deep for each tuber, spaced about three feet apart. Mix 1/4 cup of complete fertilizer into the bottom of the hole, add about 4 inches of soil, and drive a 4-5 foot stake into the hole. Then plant each tuber, with the eye pointing toward the stake, and cover it with 3 inches of soil. Water well, and when the tuber sprouts, gradually fill the hole in with soil. Don't completely cover the emerging stem and leaves, but keep building up the level of soil. This method will give your mature dahlia lots of underground support. As the stem grows above soil level, tie it loosely to the stake. Dahlias growing in enriched soil won't need additional fertilizer throughout the season, but should be watered every week during the growing and blooming season. Plan to supply one-inch of water per week to each of your dahlia plants. Following the above guidelines should provide you with healthy, happy dahlias.