JORDI: You are the second person to ask me this very same question. I suppose this idea has come about because plant nurseries and growers manipulate the light environment by placing the plants under cover. This will force the poinsettias to change color earlier making them available for stores to sell during the holidays.
Poinsettias are native to Mexico, so you can imagine they are exposed to plenty of sunlight on a regular basis. The bracts or specialize leaves change color once the days become shorter as this marks the beginning of cooler temperatures and reduced sun exposure.
It is not necessary to put poinsettias in complete darkness but it is important to keep them away from night lights once October arrives. If the plants are exposed to bright night lights such as street lights, the bracts will stay green. If grown in pots, do not let the roots sit in water as they will easily decay. These plants prefer moist but well-drained soil. Fertilize in small increments from May through September.
Cut the stems down to about 12 to 18 inches from the ground after the fear of frost if over. You may need to cut them a few times during growing season to keep them short and full but stop pruning after September 10. The fancy hybrids do not grow as easily as the standard red ones.
One other quick note – poinsettias are not poisonous to humans or pets. Some people may have a skin reaction if exposed to the white sap found in the stems. For more complete information, and further details about establishing poinsettias in your outdoor landscape in Florida, look at this University of Florida publication
QUESTION: I will be bringing my plants indoors. I have heard it will help to add aspirin to the soil to help prevent disease. Is that true? BM
JORDI: I was unable to find any research information regarding adding aspirin to soil to prevent plant disease. There is extensive research which documents aspirin provides no benefit if added to the water of cut flowers.
I see no reason to add an anti-inflammatory chemical to the soil of any plant. I would be more concerned about one of my pets finding the pill attractive and it potentially causing problems for the animal.
When bringing plants indoors when they are normally outside, let us consider a few important things. This will be a major change for the plant regarding air circulation, water and light exposure. Keep the plant in as similar a light exposure as possible. Avoid over watering as this can potentially kill any house plant. Winter is the dormant season for most plants therefore consider delaying any fertilizing until it is time to put the plant back outside.
If the plant develops leaf spots or browning, consider bringing it to one of our plant clinics for an examination. We can determine if the problem is caused by a disease pathogen or an insect and then prescribe the appropriate mode of action. We are eager to help you take care of your plants so check out the plant clinic dates and times listed on the Nassau County Extension website.
QUESTION: I am seeing a rather large shrub right now which has red, flowers. The do not spread open, but hang down. It reminds me of a hibiscus that never opens. PG
JORDI: I believe you are describing Turks-cap mallow, Malvaviscus penduliflorus. It is very easy to grow, tolerates most any type of soil but blooms best when exposed to full sun. In our area, it is a true perennial which means it will die back in the winter but should return once temperatures become warm. It is in the mallow family which explains why it reminds you of a hibiscus. Some people have called it the sleeping hibiscus. The flowers will always hang down and never open up fully – they are supposed to droop, which is why the species name is penduliflorus. I have roughly translated penduliflorus to mean – hanging flower.
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GET OFF TO A GREAT START IN THE NEW YEAR WITH JANUARY 2012 GARDENING CLINICS
Citrus Class: On January 11, 2012 from 10 am until 11 am, County Extension Director/Nassau Horticulture Agent Rebecca Jordi will conduct a class on growing and maintaining citrus plants. The class will take place at the Yulee Extension office at 86026 Pages Dairy Road and will include a hands-on instruction on pruning the lemon and orange trees at the Extension office. The class is free and open to the public. For more information, go to website or call the Extension office at 904-879-1019, or 904-491-7340.
Crash Course in North Florida Gardening January 21st and 28th, 2012
Rebecca L. Jordi, County Extension Director/Nassau Horticulture Agent, will conduct a two-day seminar covering topics on proper landscape practices and plants for our Northeast Florida area. The classes will be held on January 21, 2012 and January 28, 2012 from 9 am until noon at the Yulee Extension office. Newcomers and those new to gardening will gain much-needed information for their home landscapes. Registration and payment of $50 per person/$75 per couple (one book will be provided per couple) must be completed by Friday, January 13, 2012. Please make checks to Nassau County Extension. For more information see the website at: http://nassau.ifas.ufl.edu/horticulture/crashcourse.html, or call the Extension office at 904- 879-1019 or 904-491-7340.
[/box]Rebecca L. Jordi
County Extension Director
UF/IFAS Environmental Horticulture
Nassau County Extension
543350 U.S. Highway #1
Callahan, FL 32011
904 491-7340 or 904 879-1019