To grow show worthy Dahlias, you need to pinch unwanted growth strategically. We discussed this at the last general meeting and are putting it into action in the trial garden. Here are some notes and visual aids for your reference. We referred to an article written by Randy Siem, Timing Blooms for the Shows, which breaks down the timing of pinching so many days ahead of the show, based on bloom size. James Dahlin converted the information into this nice chart, which we are using at the trail garden. I just updated it for 2019 and added a Timing Calendar
If this seems too complicated, at the last meeting Larry Bagge offered a simpler variation that uses 65 days for all sizes, B or greater. Eric illustrated it in this simple chart. Note, you may have to top earlier if a bloom has started. A few definitions are required.
Topping – pinch off the very top center, which may contain 1 to 3 buds. Do this before the stalk gets more than a quarter inch diameter, otherwise the stem will be hollow and open. Topping forces energy into the remaining laterals to grow into major branches.
Debranch – pinch off the small lateral growth between the stem and the leaf before it can become a branch. By limiting the number of laterals allowed to grow you force the energy into just a few (see chart) major branches which will grow better blooms.
Disbud – pinch off all buds until the Last Pinch date; because they will be too early for the show. After that leave them alone until several are 3/16 to 1/4 inch diameter. By the Disbud date, pinch off all but one bud on each branch so that it will get all the energy and produce a magnificent bloom for the show. After cutting a bloom, recalculate the disbud date for the next show. Use your judgement, a few extra blooms look nice in the garden.