All the work during April and May is coming to "bloomition." Every week new flowers will appear on your plants. In Virginia, rain has been sporadic. The dahlias, like many other plants need about an inch a week. They are growing feeder roots now and are no longer feeding from the tubers. These roots will grow close to the ground. By the end of the season they will spread up to 12" from the stalk. The latest news is to use grass clippings over newspaper as a mulch. I used penetrable horticultural cloth with pine straw on top.
Growing dahlias in the Adirondacks
Whether grown in the ground or a container, be sure to remove the blooms as they die out. This will encourage the growth of new blooms until frost. If you intend to encourage cutting flowers, when buds appear, dis-bud the two side buds and remove two or three lateral shoots down from the top bud. Not sure of some of the terminology? See the grooming article below as well as the videos.
Depending on the weather, you could encounter mildew or mites on foliage, either at the top or the bottom of the plant. If you suspect this, take some leaves to a reputable garden shop, or look on-line to find organic or chemical treatments.
Jackie Mae Staas
Blooming time is also a good time to confirm that the tag matches the bloom -that is if you care or intend to give away tubers in the Spring.
In most areas, August is a hot month. The blooms will improve in September and October. A little care now will go a long way.