Sep 18, 2026 12:00 PM
Adding Height To Your Poinsettias
PROBLEM: Just about every year around week 40 or so, we get calls from growers with poinsettias that are still a bit on the small side. These growers are concerned they won’t hit their finished spec. While it’s usually getting close to Thanksgiving-time ship dates, there is still time to push some additional growth in your poinsettia crop.
NICK’S TIP: Here are a few methods for getting your points to fill out quickly and still have enough time to tone them before they ship and/or hit your retail benches. Remember that poinsettias have terminal inflorescences, meaning growth stops at the top where cyathia form.
Because of the plant structure, you don’t want to encourage overly lush growth that could risk burying cyathia below the canopy. Consider your end goal before you start to push the crop.
How much height to you need to add to the crop and how much time do you actually have to do so? Always reserve the last approximately two weeks (at least) in your crop cycle to cool your air temps and promote good tone. CAUTION: Don’t push the plants right up until shipping!
Here’s a question to consider: Are you satisfied with the height of your plants, but you wish bracts were larger?
Once you have your goal set, put an appropriate plan into action. If you decide to push growth for additional height, make the decision based on graphical tracking data. If you haven’t been doing graphical tracking, check out one of my past TECH TIPS and use the principles to quantify where your crop is now versus where you need it to be in a few weeks.
If your crop only needs a gentle nudge (about 3 to 4 inches in height), you can likely make up the size you need by slightly increasing air temps, your DIF (difference between day and night temperature), fertilizer, and/or watering a little heavier. However, start this “conventional” push now and only employ this approach for a few weeks. Give your crop extra time to tone-up to avoid having soft plants at finish, because soft growth will lead to damage/lodging when plants are sleeved and shipped.
If your plants need to put on a significant amount of height (6 inches or more), use of plant growth regulators (PGRs) containing gibberellic acid (GA) will be your best insurance policy. In particular, use PGRs that contain both GA4+7 and benzyladenine (BA) like Fresco and Fascination, as they typically yield more consistent results than ones with only GA3.
Drench applications of Fresco (Fascination is not labeled for drench) will enhance growth evenly across the plant, whereas sprays have a more localized effect at the spray site.
Rate and number of applications needed will vary by region and cultivar, but a 2 ppm drench is a good starting point for many growers. Apply and wait a week to observe the crop’s response before making a follow-up application.
Consistent application volume across the crop is key. Apply 1 fl. oz. per inch of container diameter plus 1 fl. oz. per additional cutting to each pot. For example, a 6-in. pot with 1 plant per pot (PPP) would need 7 fl. oz. (about 205 mL) and a 10-in. with 3 PPP would need 13 fl. oz. (385 mL) per pot.
If bract size enhancement is your goal and you don’t want much additional height on the crop, an approximately 3 ppm foliar application of Fascination or Fresco 7 to 14 days before anthesis (when cyathia are showing pollen) will increase bract size.
Keep in mind that late foliar application may impact plant height. Test a few rates on different cultivars before applying to your whole crop.
Foliar applications of Fascination/Fresco can also deepen the color of darker-bract cultivars and brighten the bracts of white cultivars.
Be aware of the risks associated with applying foliar sprays to poinsettias with mature bracts. Some growers experience increased Botrytis pressure after applying these late foliar sprays due to prolonged leaf wetness and high relative humidity in the crop canopy. Adjust environment controller setpoints to eliminate prolonged periods of high humidity (more than about 4 hours) or apply an appropriate fungicide ahead of time to minimize the risk of encountering disease pressure.