Poinsettias

Q. How do I water and care for my Poinsettia plant once I have brought it home? Does it need light? Fertilizer?

A. Water only when soil is nearly dry to the fingertips one inch deep. Allow bottom drainage so that the plant never sits in water. A constantly moist soil will cause root rot and the plant will die. If you under-water, the leaves will wilt, so water promptly. Poinsettias are fairly forgiving and will bounce back quickly but brown edges on the colored bracts will remain. Never allow indoor temperatures to drop below 65 F. Give it as much indirect light as you can. Keep out of any heating duct draft or cold air from windows or doorways. Give fertilizer as Schultz or Miracle-Gro as recommended for house plants. Pinch off dead and yellow leaves and cut back dead branches.

Q. I have Poinsettias from last Christmas. They are growing very well but I can't seem to make them turn red. I keep them by a window and I hardly ever open that blind. Do you have a suggestion?

A. You are in deep trouble [11/21/01] for the Holidays. You need a video copy of the TV show I made locally a couple weeks ago on poinsettias.

The plant is a short day plant, meaning it will not bloom unless it receives about 10 weeks of days no longer than 9 hours. I prefer to look at it as a long night plant, meaning they need nights, total darkness, no tiny light near them at all, for 10 weeks of 14 hours. If a lamp is nearby, or if a person goes into the room and turns on a light for a minute once, or if a street light reflects into the room, the plant will not initiate flowers.

The red leaves we love are really modified, called bracts, not flowers. The tiny yellow centers which last a couple days are the actual flowers. But, the leaves will not turn red or pink or cream unless grown as a long night plant!

It is best for you to try again next year, or start right now, for blooms in about 2/1/02. But, they can be enjoyed as lovely green house plant with even an outside trip into the yard for the spring and summer.

In Mexico, from where they originate, they will bloom outside in the winter with a little light interruption. But they are accustomed to it and are not our greenhouse hybrids. BTW, have you seen the dark purple one yet? Rare...I have seen only a picture.

Q. Why are my poinsettias losing their leaves? They are new and beautiful. I don't want to lose them yet.

A. A plant brought from a nursery or florist shop into your home will most likely drop some leaves, due to the cultural changes. It is a type of shock. But, if you do a couple things, you may reduce this problem:

Water the plant only when the top inch of soil is dry to the touch. Remove the outer foil or punch several holes in it to allow water to flow out into a bottom saucer. Keep this saucer empty of sitting water. Place the plant in an area with good indirect light, no direct sunlight, but not total shade either. The leaves need light to continue to be green. Feed the plant with dilute house plant food once every two weeks, at a rate of about 1/4 to 1/2 teaspoon per gallon water. Make sure that the plant is not sitting in a draft, either from an opening door, cold window, or heating vent.

Remove bottom yellow leaves to prevent spread of disease. Keep away from a heat source as a candle or string of light bulbs. Plants will stay fresh longer, the colored bracts stay on the plant, and leaves will not yellow or brown so much if you have the plant in a room with a cool night temperature. Extreme heat in the home reduces the length of the plant's display.

Beverly writes~
Can you take cuttings for next year from the poinsettia? I have a super white one and a gorgeous pink variegated I would love to duplicate in case I lose these.

A. Yes, they root very easily from cuttings. That is how greenhouse and nursery workers start the next year's crop. We put five cuttings per 6" pot, cut to a length of about 5", with a good inch below the soil surface. They must be kept in a high humidity area, or covered with plastic or glass. They root quickly, maybe within a week or two, especially if you use a rooting hormone as Rootone. Follow the label directions and tap off excess.

Once the cuttings are growing, prune out the growing tips. This will force side buds to break and lead to a full, bushy plant. Give them good light, fertilizer and warmth. I recommend that you start the cuttings once the days get longer, around March.

Maria writes~ My poinsettia plants have white spots on them that look like dust. I do not see any bugs on them & for now I have wiped it off with a wet towel. Do you have any idea what it is?

A. I suspect powdery mildew. It grows on foliage and flower stems when there is poor air circulation and high humidity. Make sure that the plant gets rotated often, is in good ample light but not too hot, and that leaves are not lying on top each other. If you can provide some air movement with a window slightly cracked, a fan or an open door, it will cause unpleasant conditions for the mildew to flourish.

Benomyl is commonly sprayed on the leaves for control. Check your local nursery and see if they have a control for mildew on roses, a plant which mildew loves. Follow the directions carefully, spray in the morning and keep out of direct light until liquid has dried.

Steve writes~
I need some advice on our poinsettia plants outdoors in South Florida. When and how do we prune? Everyone seems to have their own opinion. Right now, the plants which bloomed in December to everyone's delight, are going back to all green leaves from yellow and red. Every other day, they get 15 minutes of sprinkler system water. They are leggy. I have not fertilized them lately. Advice on type and frequency of feeding? We use the semi-north side of the house (not constant sun) and have ready access to water. Added some liquid Miracle-Gro.

A. By late March or early April, cut your poinsettia back to about 8" in height. Continue a regular watering program, and fertilize your plant with a good, balanced all-purpose fertilizer. By the end of May, you should see vigorous new growth.

Continue regular watering during the growth period, and fertilize every 2 to 3 weeks. Pruning should be done during the summer to keep plants bushy and compact. Tip prune and remove tall, lanky out-of-place branches. Late June or early July is a good starting time, but be sure not to prune your plant later than September 1. Keep the plants in indirect sun and water regularly.

A soil with a considerable amount of organic matter, such as peat moss or leaf mold, is highly recommended. Be sure the planting bed is rich in organic material and has good drainage or roots will rot.

The poinsettia is a 'photosensitive' plant, meaning that it sets bud and produces flowers as the Autumn nights lengthen. Poinsettias will naturally come into bloom during November or December [as they do outside in Mexico, their home], depending on the flowering response time of the individual cultivar. Timing to produce blooms for the Christmas holiday can be difficult outside of the controlled environment of a greenhouse. Stray light of any kind, such as from a street light from poles and cars or house lamps shining outside, could delay or entirely halt the re-flowering process.

Starting October 1, the plants must be kept in complete darkness for 14 continuous hours each night. During October, November and early December, poinsettias require 6 - 8 hours of bright sunlight daily, with night temperatures between 60 - 70 F. Temperatures outside of this range could also delay flowering. Continue the normal watering and fertilizer program. Carefully following this regime for 8 to 10 weeks should result in a colorful display of blooms for right around the holiday season!

Assistance from the 75 year-old Paul Ecke Poinsettia Ranch, http://www.ecke.com

Regina writes~
An article said to pinch the poinsettia stems back to 4-6 inches long.

1-Will the leaves be growing during the time that the stems are shortened?
2-Can I cut them if the stems are a little too sturdy for "pinching"?

A little more than half of the red leaves have fallen off, but the stems and green leaves seem very healthy, so I really wanted to see if I could keep it going.

A. The red 'leaves' are actually modified bracts which are leaves with the actual flowers coming from the inner stems, the little yellow buds which fall off after a few days in the house. Allow all the red bracts to fall off and discard. What is described is trimming back the stems [using a knife is fine] to promote low bushiness during the summer growing months. It is desirable that at least one green leaf remains on each lower branch. New leaves will pop out from the top side buds of these stems, usually two per stem. Allow them to grow two sets of leaves and pinch them again to make the plant even more bushy. The more stems you have in the fall, the more red colored leaves you will produce for the Holidays.

Grow the plant in a rich, well-drained soil in part sun and keep watered especially during dry periods. Fertilize regularly with an all-purpose food. Do not keep soil soggy or plant will rot. Watch for any insect invasion and treat accordingly.

For the plant to produce flowers and colored bracts in the winter, it must be subjected to at least 14 hours darkness each night for 10-12 weeks. A closet works well, as long as no nightly light is allowed inside. Each morning bring the plant back out into good indirect light in the house. Count back 14 weeks from Christmas and that is the date you must start the dark night program.

Julles writes~
OK, now I have my poinsettia...now what do I do?

A. Position the poinsettia plant carefully away from drafts and heat sources which will cause leaf drop. Do not put on top of a television, near a fireplace or ventilating duct or near a door. They like room temperatures 68-70 F; the color lasts longest when temperatures do not exceed 70 F during the daytime or fall below 65 F at night. They need at least 6 hours indirect sunlight per day. If direct sun cannot be avoided, diffuse the light with a shade or sheer curtain. Allow to dry out slightly between waterings; water when the soil feels dry to the touch, so that the water just starts to come out of the drainage holes. It is important not to overwater plant or allow it to sit in standing water. If keeping in a decorative container, remove before watering and let drain completely. Standing water can lead to root rot. Poinsettias need moist air; mist frequently during the blooming season. While blooming, no need to fertilize but apply after the blooming season is over to maintain healthy foliage and promote new growth. Poinsettias will reward with brilliant color for many months. When the leaves have fallen [usually by late March or early April], cut entire plant back to about 8" tall. Continue a regular watering program and feed with a balanced fertilizer. By the end of May vigorous new growth will appear. Transplant into a larger pot, continue regular watering during the growth period and fertilize every 2-3 weeks. Once all chance of frost has passed and night temperatures average 55 F or above, place poinsettia outside, being sure to bring it back in if there is any chance temperature will fall below 50 F. If pruning is necessary to keep the plant bushy and compact, stop by September 1. From October 1 the plant will need to be kept in total darkness for 14 continuous hours each night. Cover with a black polythene bag or a large box as any light as that of a streetlight or house lamp will stop the reflowering process. In the daytime from October through December the plant will need 6-8 hours of bright sunlight daily with night temperatures between 60-70 F. Temperatures outside of this range can also delay flowering. Following this regime for 8-10 weeks will produce a flowering poinsettia for the holidays. The actual bloom time will depend on the particular variety.