Some of us have been thinking about planting dahlias for three or four months. June, however, is also a planting month. Tubers develop on their own time cycle. When I put them out in March, in flats with heat pads, they were very slow to develop eyes and shoots. During May the process dramatically speeded up. Possibly, it was longer days and warmer weather. Many of the dry tubers that I had given up on, now have sprouts and rootlets. They may bloom a little later, but will continue to frost, and still yield tubers that can be stored.
If you have not yet acquired tubers, they will probably be available at garden centers and big box stores. Even some of the commercial dahlia sellers on the internet are offering discounts on their remaining stock. But move quickly, this has been a big year for new gardeners.
I just finishing planting this week. Some of my plants in pots were 18” tall, and others, from flats, have not shown a spout above ground. We have had considerable rain, but my drainage is decent, and I doubt that any will drown in too much moisture. That can happen before the tuber develops a good root system.
We put in stakes, planted, and tagged. Then I made a map of each row. I have never seen a bird remove a tag, but I think some can. Dahlias will continue to make feeder roots almost at ground level; a time-release fertilizer will do for most of the season unless you are growing for exhibition. There are innumerable fertilizing theories—we have included some links below.
