Eight Common Calibrachoa Mistakes
January 23, 2009 
There are some key things to watch for when you’re growing calibrachoa, especially during rooting and the first weeks after planting rooted liners. Mistakes during the first weeks will take a long time to heal, but Selecta First Class is trying to help calibrachoa growers, like those growing MiniFamous varieties, avoid eight common mistakes. Here are eight mistakes to avoid Selecta published in a recent eNewsletter.
1. Variety Selection
Know what the final product should look like and base your variety selection on it. Growing a small pot crop using 4-inch pots to quart size and easy-to-ship mono-baskets, use a compact variety such as MiniFamous ‘Compact.’ For larger and impressive mono-baskets and mixed baskets, the traditional MiniFamous line is the better fit.
2. Scheduling
It’s a common sight to see overgrown pots and baskets at retail. Calibrachoa is a quick-to-finish crop and should not be started too early. Check out the recommended finishing times for your area and know your desired sales date. Use this information to schedule your crop and plant accordingly.
3. Don’t Over Mist In Propagation
The cuttings are small and thin, and more mist will enter the plug compared to the large petunias, for example. It’s easy to over-saturate a calibrachoa liner without noticing it until the cutting shows it (when it’s too late). It’s important to avoid over-saturating the plug the first 10 to 14 days until initial roots have been formed. Signs of too much water include uneven rooting, yellowing of the growing tips, uneven growth and hardened cuttings.
4. Start Warm
Calibrachoa like it warm during propagation, and especially during the first two weeks the media temperature should be at 70°F (21°C). Don’t harden off your liner too quickly or harshly. Drop the temperature by a couple degrees. Use cool mornings and higher light levels to tone your liners.
Hardening off too fast will delay rooting of the liner after transplanting, reduce branching and delay finishing. After transplanting the liners, keep the temperature up. Maintain night temperatures of 61-64ºF (16-18°C) and day temperatures of 68-72ºF (20-22°C), until plants have nicely branched and cover almost all the substrate surface of your pot.
5. Substrate/Fertilizer/pH/EC
Choose well draining, peat moss-based substrate for your calibrachoa crop. Most newer genetics can handle a pH between 5.6 and 6.2. Know your water and use the correct fertilizer for it. Check your root system and keep it healthy. This becomes much easier if you use a well draining, peat moss-based substrate.
Keep the salt level below EC 2.0. Low salt levels will lead to light green or slightly yellow plants, but high salt levels will burn roots and may lead to root disease and problems that aren’t so easy to correct. A pH that’s too high is as bad as one that’s too low.
Water regularly and avoid jumping from one extreme to the other, as this will damage the root system. The right genetics in combination with good substrate, the right fertilizer and the correct watering will get you through your crop without the need for special treatments.
6. Pinching
It sounds so easy, but pinching a liner at the perfect time will make a huge difference. Don’t let your liner overgrow. Keep cuttings soft and growing before you pinch, as hard cuttings won’t branch as well.
Apply PGRs at an early stage in propagation so the cuttings stay nice and compact (avoid the initial stretch). Pinch early and soft so good basal branching is the result. Especially for pot and mono-basket production, you should keep a close eye on the pinching process.
7. PGRs
Using the right PGR at the right moment will avoid a lot of headaches later on. Avoid planting vigorous varieties in small pots, as this will complicate the crop. If it’s necessary, make sure to stay on top of PGRs and consult your supplier for more specific instructions.
Some growers might prefer to use a spray and drench combination for calibrachoa. Start in propagation with about two applications of 2,500 PPM B-Nine (or 10-20 PPM Sumagic) and apply the drench according to the plant format. For pots, it is suggested to use 0.25 PPM Sumagic as a drench the moment side shoots are about 1 inch long. Apply the drench before you lower the temperature for your crop.
Baskets will get one more spray at the same stage (when side shoots are about 1 inch long) and the drench later on. I like to drench my baskets with 1 PPM Bonzi, when plants reach about 75 percent of the desired size. Additional spray applications or a second drench application can be applied if necessary. For very vigorous varieties (like MiniFamous Double Pink) it is recommended that you double the rates (which equal Selecta’s petunia recommendations).
8. Avoid Late Flowering
A frequent complaint is about late flowering. This may have to do with the variety selection, but it can also be related to treatments during production. It has proven that using HID lights during propagation will result in early flowering. Avoid the use of B-Nine and Florel (especially in northern areas) as much as possible, as it will delay flowering. Keep the temperatures up (especially at the beginning of the crop) and avoid late pinching. Keep light levels up and grow plants on the dry side.
For more tech advice, tips, ideas and an interactive forum, check out http://minifamousclub.com.
Subscribe to eNewsletter
