Calibrachoa is still considered a relatively new plant for the ornamentals industry, and while growers have learned to grow it successfully for the most part, there are a few common challenges that arise with it. Here are several production pointers for growing calibrachoa, courtesy of Proven Winners (which produces the Superbells series).
First, it’s important to think differently about calibrachoa. A woody shrub in the wild, it grows in full sun in tropical to moderately temperate areas. It has a slower reaction time to fertilizers and correctives that you may have to use to treat the crop.
Calibrachoa are only recommended for container growing, and part of the reason is that they like to dry out between irrigations. Keep this in mind when setting up your irrigation schedule. Calibrachoa can dry down to flagging but never to full wilt because every time it goes into wilt it loses a little more vigor.
Calibrachoa like an even soil environment with nutrients. The pH should be between 5.8 and 6.2. When you get above this range, iron ties up and your crop will begin to yellow in the growing tips. Treatments can be applied to offset a pH swing — (refer to the Proven Winners culture guide for suggested treatments). Make sure you also monitor your pH for steady success.
Calibrachoa like moderate feed levels. Use a complete, balanced feed at 150 to 200ppm with a soil EC below 2.0. Remember to dry down between irrigations. If your EC in the crop creeps up, a couple clear water irrigations between feeds will get the EC back in range.
You can control your growth with light, temperature, and feed, but plant growth regulators may still be necessary.