Whether you plan to grow a dahlia or two, or a hundred, April is the month to give them a good start. While planting time for most of us is still a month away, if the dahlia gets established before going into the ground, it is better prepared to meet the challenges of heat and drought after it is planted. I have frequently written that you can just put the bare tuber in the ground, and it will grow (info here) and that is true. Some cultivars are so vigorous that they will put up shoots in a bag of dry vermiculite. But why put them to the test?
A bit of botany will help. The initial growth of the dahlia comes from the tuber - which is technically a root. However, that is just the starter engine. If the dahlia is to develop, it needs to create roots and a stem. Those are the parts that will generate the power for the plant to grow and flower through the summer.
By potting up the tuber for a time before it goes into the ground, you can jump start the plant and better prepare it for the garden. In late March I took the tubers out of storage and placed them in flats (info below) with a mixture of Pro-Mix and vermiculite. I made sure the stem-end of the tuber was visible. A light sprinkle came before they were set out on tables. In essence, I turned the key in the ignition. Since the growing energy at this point comes from the tuber, neither light nor watering is necessary.
There were only a couple of eyes on about 150 tubers. I did not despair! As the days get longer in Virginia and the temperature warms, the eyes in the tubers will come out of hiding. When I put away the cut-up dahlias in the fall, I did not look for eyes. I put all the divisions from a clump in a plastic bag with vermiculite. In fact, some tubers will have hidden eyes, and some will not.
