American Dahlia Society
July is for Anticipation
July 2021
Kelsey Betelgeuse, an early bloom in my garden, more to come!

2021 has been a wild year. The West and Northwest have experienced extraordinarily hot weather. This is significant in the dahlia world because so many commercial growers and hybridizers live in those regions. In the East and Mid-West, we have experienced a rollercoaster of rain and temperatures. One of our more conscientious growers in Maryland is battling with a ground fungus that attacks the roots. Nevertheless, for many of us the season goes along and the dahlias, like tomatoes, are begging to put out buds and blooms.

Whether you are growing one dahlia plant or a hundred it is important to keep the ground around the plant mulched. The roots of the plants are now growing; the tubers have done their job. Dahlia roots grow near the surface - there are no taproots. The mulch insulates them from the heat and helps retain moisture. See the links below on mulching for more information.

In clay soil the water from rain or sprinklers tends to hang around. Too much water and the roots will suffer from a lack of oxygen. Too little, and they will wither. The books refer to one inch a week as ideal. If you rely on soaker hoses or sprinklers, a cup in the ground can help you gauge how much water you are giving your plants.
During late July many growers will fertilize with a water-soluble fertilizer to give the plants a boost. If you start with a long-lasting slow release fertilizer, a second application may not be necessary.

If you are growing for cut flowers, be sure to remove the spent blooms, and prune (dis-branch) the side-shoots (laterals) on the flower stems, two or three levels deep.
Micro Dahlia U2 Fire growing in a pot, blooming since early July
For plant grooming advice see the link below.

Additional ties may be necessary. as the plants have gotten taller, to hold the plant up during a storm or heavy wind. Even a stem that looks strong and healthy may succumb as dahlia stems are often brittle.

Critters and fungi: This is a touchy subject. The big three in my area are red spider mites, broad/cyclamen mites and mildew. If left untreated they can damage a plant, or at least its attractiveness. The biological, organic, and chemical remedies are endless. The degree of intervention depends on how obsessive you are about having picture-perfect plants and blooms. I make no recommendations, because it is a matter of horticultural conscience.

As we move into August, enjoy your garden and be sure to groom the plants.

Good gardening,
Harry Rissetto