It’s November. With pansies, kale/cabbage and bulbs planted there is little to do in the ornamental garden but pull hen-bit. For the greenhouse grower, we are all worried about that red plant soon to grace everyone’s fireplace and/or table. Thats right, poinsettia.

The poinsettia was brought to America by the U.S. Ambassador to Mexico, Dr. Joel Roberts Poinsett in 1828. And despite what most say, is not poisonous (unless you are eating salads of it).

With the poinsettia being the #1 potted plant in the U.S, every greenhouse grower is sure to have them on their benches. Most growers will buy rooted cuttings to be shipped in around August. Depending on the variety and the size of the plant needed the grower will pinch the plant in September. Pinching is done to destroy apical dominance. Once the tip is removed from the plant the concentration of auxin (the hormone responsible for phototropism, geotropism, apical dominance and promoting root formation) the lateral buds will begin to grow. See the pinched plant below that was pinched three weeks before the picture.

Some growers will apply a plant growth regulator such as Cycocel and/or Florel which are synthetic hormones to keep the plant short.

Poinsettia, like mums, are photo-sensitive plants. They require a day length shorter than 12 hours in order to bloom. Basically a chemical that is produced inside the plant that can be destroyed by light can sufficiently build up and trigger the plant to bloom. The dark must be uninterrupted. If the poinsettia sees more than 2 fc for even a moment, blooming can be delayed. High temperatures can also be a factor.

Sounds pretty simple…Right? Well there are a few more things to consider; nutrients (I send tissue, media, and water samples to a lab to be tested), space, watering, fungus and whitefly. And if you’re like me, six months more of work!!! Thats right I produce my crop myself from stock plants.

Here is how I do it.

Week 13 (middle of March) I receive around 1,000 rooted cuttings. The cutting come to me rooted in a oasis wedge that is very similar to florist foam. I plant the wedges into a 6.5” pot and place them pot to pot. They end up taking one bench (6’x40’). I grow them on and pinch them around the end of April. By the end of May they go from taking up one bench to six benches. In June I begin taking cuttings. The photo below is one of a group of cuttings produced by a "direct stick" method. I root them under mist and shade. Over two to four weeks I reduce the amount of mist and increase the amount of light.

When to take cutting depends on the rooting time, vegetative build-up (after pinching) time plus blooming time. Then you count that time back from your sales date and that is when you take the cutting.

You may notice the pinching and Auxin and most gardeners know that if they remove the tip of their plant the lateral branches will begin to grow. Consider doing the opposite of apical pinching and encourage apical dominance. You can remove the lateral buds and encourage one large flower as seen in my standard poinsettia below (three plants in a pot).

You can also take the idea of destroying apical dominance and combine it with encouraging apical dominance to produce a poinsettia tree. In March pull out some of your stock and do not pinch them. Grow the plants on. While they grow remove the lower 50 percent of lateral buds. In September (with the other plants) pinch the plant. Pinch again to get the poinsettia tree.

Now I may have made poinsettia production sound fairly simple. But before all the greenhouse growers out there grab their pitch-forks and torches, let me ensure you poinsettia production is very involved. I have lost many nights sleep worrying about flowering on time, flowering too soon, pest (whitefly in particular), nutrients, the plant growing too big, or the plant being too short, growing too many pink flowers, not growing enough red, are the heaters working, etc..

So as you enjoy that "decoration" on your fireplace or table. Take a moment to think of the jorney we took to this holiday season.