Rick Durham, Consumer Horticulture Extension Specialist, Department of Horticulture, University of Kentucky.

Poinsettia toxicity.

Contrary to popular belief, poinsettias are not considered poisonous. Research at several institutions has shown that poinsettia foliage is not toxic. In fact, one source indicated that a 50 pound child would have to ingest over a pound of poinsettia vegetation to exceed experimental doses that were considered non toxic. That's roughly 500 leaves or flower bracts, and even at that level no toxicity was observed. Rest assured, the poinsettia is the most widely tested plant in commercial trade.  Even though they are non toxic, poinsettias are still considered non-edible. As with all plants, some people have reported skin sensitivities when exposed to poinsettias. Individuals may be especially sensitive to the white milky sap called latex that poinsettias bleed when a leaf or flower is injured. Such individuals may experience some discomfort if a leaf or flower bract was accidentally ingested. Curious cats may choke on poinsettia foliage because of its fibrous nature. And of course, active children are apt to put anything in their mouth. A good practice is to put all non-edible materials, including poinsettias, out of reach.

Poinsettia flowers.

Few plants offer such a vivid display of color as the poinsettia. But the bright red, pink, white, or variegated structures that are so attractive are not actually the flowers. These structures are modified leaves called bracts and the collection of bracts on a stem is called an involucre. The actual flowers are present but not very showy. To find the flowers look for one or more cup-shaped structures called cyathia near the center of the involucre. Within the cyathia are the actual flowers and these are far from showy. The flowers are either female, containing a single pistil, or male, containing a single anther. And that's about it, they have no sepals or petals which are the parts that provide the showy color on most plant. The fact that the attractive part is not a true flower is an advantage. Most flowers are relatively short-lived while the poinsettia bracts are very long lasting and may provide a nice decorative plant for the ever-extending holiday season.
 

Caring for poinsettias at home.

Poinsettias are not difficult plants to keep going indoors. Try to give the plant as much light as possible like under a skylight or near an east or south facing window. If possible, try to expose the leaves to one or more hours of direct sunlight each day. Drafty areas near radiators or ceiling fans should be avoided and it is never a good idea to set plants of any kind on a television or other electronic equipment. Water the plant as needed but don't over water. Poinsettias are susceptible to several soil-borne diseases and wet soils can cause the plants to succumb rather quickly. To determine if it's time to water, stick your finger down into the soil at least to your middle knuckle. If you can feel moisture, wait another day and check again before watering. Never let the plant stand in water. Pour off water that may accumulate in a saucer or dish under the pot and remove the pot from the cellophane pot cover when watering. You can fertilize the plant every couple of weeks with ordinary house plant food. A well cared for poinsettia can last for several weeks after the holiday season.
 

Live Christmas trees for the holidays.

Selection and purchase of a Christmas tree is an annual event for many families. More and more people are choosing to use a living tree that can be transplanted to the landscape once the holiday season is over. For many people this is a good option since the money usually spent on a disposable tree can be invested in a specimen that can add value to the landscape. However, care must be taken when bringing a temperate tree indoors for any length of time and then transplanting it outdoors, especially in winter. Here are some pointers to increase the chances of success.

• Living trees are generally marketed as either balled-and-burlapped or potted plants. Expect to pay more for a living tree than a cut tree and realize that nurseries are reluctant to guarantee your purchase since the tree will not be planted during the normal planting season.
• Consider where the tree will be placed in the landscape. Most Christmas tree species will eventually reach a height of 40-60 feet so appropriate planning is essential.
• Pick out the tree early so that a nicely shaped, vigorous plant can be chosen. But plan to keep the tree inside for no longer than 7-10 days. In the interim, go ahead and dig the hole where the tree will be transplanted and store the tree in this location. Be sure to keep the roots moist. Having the hole dug ahead of time will avoid any problems of inclement weather after the holidays.
• When it's time to bring the tree indoors, the main concerning is to protect the plant from drying out. Avoid placing the tree near a radiator or other drafty place-keeping the tree on the cool side is also preferable. Place the tree in a large tub or cover the root ball in plastic to avoid spilling water onto the floor. Allow water to evenly soak into the root ball by applying it as a slow stream. It may be easier to water the plant by placing ice around the top of the soil and allow it to slowly melt and soak into the soil. Don't go overboard and keep the root ball extremely wet as this may damage the root system.
• After Christmas, the tree should be planted immediately in the pre-dug hole. Water the plant well after filling in the hole with soil. Water periodically throughout the winter, especially during warmer weather.
• In spring and summer, water the plant every week as you would any other newly transplanted tree.

Do fallen leaves make good mulch? Yes and no. It's fine to put a few leaves around shrubs and over dormant perennials, however, be careful not to apply to many. Applying leaves to a depth greater than two inches may cause some problems. A shallow layer, two inches or less, should not pose a problem but deeper layers of leaves tend to suffocate the plant's root system and inhibit water movement into the soil. So is bagging leaves the only answer? Not at all. Fallen leaves mixed with freshly mowed grass make an excellent addition to the compost pile. The leaves are high in carbon so if added alone they will be slow to be digested by the microbes in the compost pile. However, the green grass tends to be high in nitrogen, so mixing dry leaves and freshly mowed grass will give the composting microbes a well balanced diet. Mixes such as this may decompose very quickly and thus the compost pile may need to be turned regularly (every few days) until the interior temperature of the compost pile does not rise above about 110F. After a few weeks the compost can be used as a mulch or soil amendment in the garden, yard or landscape.