Life of the Dahlia-Chapter 6 June

Last year many dahlia growers had to deal with cold temperatures and heavy rainfall. Conditions delayed normal growing conditions and impacted many of the early dahlia shows with limited blooms to exhibit. This growing season is just the opposite with favorable growing temperatures. Only one problem, lack of rainfall, which has delayed the growth of some tubers. My garden soil required watering, especially when temperatures reached the mid 80’s or higher.

I’m sure many dahlia addicts have by now established a daily routine of cruising around your dahlia garden. Some are admiring the rapid healthy growth of the new emerging plants while other, like expectant parents, are still waiting for the shoot to emerge. Some have even dug up the tuber to see exactly what’s going on in soil to either find a healthy shoot ready to pop or a rotted tuber. Sometimes tuber growth takes way longer than we want, especially when you planted the tuber 6 weeks earlier. For unknown reasons, lack of moisture, soil temperature, whatever, the tuber will finally kick into gear and grow or will have rotted. Then there is the healthy plant that suddenly wilts and dies. This usually occurs when the soil is too wet or there is some fault with the tuber and rots occurs. The new shoots haven’t had a chance to grow enough roots to grow the plant.

I just completed my dahlia “rounds” for the day, pulling weeds, inspecting plants for insects, observing the growth of the plant for healthy leaves, and stopping (will talk about later) an occasional plant that is growing rapidly and showing a bloom. Many of my plants are reaching enough height to start tying to the stake. The tying material can be green paper/ wire garden ties, binder twine, or almost any commercial product. The tie must be strong enough to support the plant the entire growing season. I use Sisal twine (2500feet), purchased at Home Depot, to tie my dahlias, first to the stake, then strung down the rows. Another method that is becoming popular is the use of plastic netting. The Silverdale Post office is set up with netting for this growing season. As the plants reach around 24” in height, netting is placed, and the plants are guided through the opening. As the plants grow it’s important during your rounds to make sure new growth emerges through the opening or your plant will get entangled and contorted in the netting.

When plants reach four to five inches tall or more, and have established a good root system, give them a good dose of nitrogen to help speed up development. I have used Miracle Grow for years, but you can also use other water-soluble fertilizers high in nitrogen. Fertilizer can be applied by spraying the leaves (foliar feeding), and/or directly through the root zone. If you use T-Tape for irrigation you can purchase fertilizer emitter from DripWorks.com to apply water soluble fertilizer. The key is to provide a quick source of nitrogen that plants can readily absorb.

Mulch can also be applied when plants are at least 6 inches tall. Mulch has many benefits to develop healthy dahlia plants. Mulch, as it decomposes, improves the quality of the soil. Mulch also helps keep moisture in the soil due to evaporation. Mulch can then reduce the frequency of watering. Finally, if you weed your garden before applying mulch you can control the number of weeds later in the season.

Dahlia growers learned long ago that by removing the growing tip, a dahlia plant will produce multiple branches and blooms. This method is called stopping or topping. Left alone, the dahlia will continue to grow until the bloom cycle is completed, which is ok. Suggested stopping or topping can be performed now (usually mid-June) using the following guide: Variety Size Leaf pairs (from main stem) to be kept- AA and A 2-3 pairs of leaves; B 3-4 pairs of leaves; BB 4 pairs of leaves; M 5 pairs of leaves Ball 4-5 pairs of leaves; all others 5 pairs of leaves. Disbranching means removing some of the laterals (or branches) to concentrate all the growing energy into remaining blooms to maximize their size. Disbranching is done several weeks after stopping the plants. Lateral Branches to leave on plant AA and A 3-4 laterals; B 3-4 laterals; BB 4-5 laterals; M 5-6 laterals; and Ball 5-6 laterals. Both Stopping and Disbranching are techniques used by exhibitors and not required by the dahlia hobbyist.

So in summary, frequent rounding of your dahlia garden will give you a good pulse of how your garden is growing. You can deal with problem pests earlier, keep ahead of weeds, and groom your plants for optimum blooms. A timely application of fertilizer high in nitrogen will give your established plants a much-needed boost for a successful growing season! Finally, mulching will help conserve moisture and provide micro nutrients for healthier plants.