With the holidays on our minds, it's easy to forget that truly cold weather may soon be upon us. Even trees and shrubs that are hardy in more temperate climates may put on new growth late in the season here and can be open to injury from a freeze.
Plants that may require protection in home landscapes are copperleaf, banana, papaya, poinsettia, hibiscus, ixora, dwarf schefflera, carissa, philodendron, croton, bougainvillea, allamanda, seagrape, bromeliads, tropical fruit trees or any other tropical or semitropical.
Old sheets, blankets, boxes, newspaper or plastic can be used for covers, but build a frame so plastic doesn't touch the plant. Any covering material should be sealed to the ground. This will trap heat, keeping the interior 3 to 4 degrees warmer than the outside air. Apply cover late in the afternoon, before temperatures drop.
Plastic covers should be removed the next morning after the temperature is above freezing but before the sun's rays become warm enough to cook your plants. Cloth or paper coverings can remain for two or three days if temperatures are expected to go below freezing each night. More information can be found in the University of Florida/IFAS publication Cold Protection of Ornamental Plants: edis.ifas.ufl.edu/MG025.
Gifts for gardeners
Pruning shears, watering cans, sprayers, fertilizer spreaders, hand tools, seedling starter kits, seeds, labels, flower arranging materials, grow lights, potting soil and garden statuary all make great gifts. Florida gardeners will appreciate books like Month-by-Month Gardening in Florida and Florida's Best Native Landscape Plants.
If your Christmas poinsettia comes in a container wrapped in foil, remove it or punch holes in the bottom to allow for adequate drainage. Keep the soil slightly moist, not soggy, and place the plant in a bright window out of direct sunlight.
The Christmas cactus, Zygocactus truncates, usually flowers from Thanksgiving to Christmas and its leaves have pointed lobes. The Easter cactus, Schlumbergera bridgesii, has wider leaves, which are rounded. It usually flowers from Christmas to Easter. For both, allow soil to dry out between watering and keep the plant in bright light while in bloom. These are long-lived and can be kept outside in the shade most of the year. Protect from frost and freezes.
Kalanchoe, pronounced (cal-ann-ko-ee), a winter bloomer, has become popular as a holiday plant in the last few years. Flower colors are yellow, pink, red and various shades of orange. Since this is a succulent plant, let the soil dry out between watering.
Good to plant now
Pansies, calendulas, petunias, sweet alyssum, snapdragons and pinks are a few nice winter annuals to use as bedding plants or in containers. All will survive frosts or freezes and keep on blooming. Others annuals that are a bit more sensitive to frost, but good to plant now are impatiens, geranium and begonias.
Five or six weeks after transplanting, begin feeding with a light application of 5-8-8, 6-10-10 or other comparable slow-release fertilizer every two months.
Gerbera daisy can be planted throughout the year but the best time is usually fall and early winter. Choose a well-drained area and amend with organic matter. If you loosen the roots without breaking the soil ball, the plants will usually recover rapidly and become established more quickly. Gerbera crowns gradually sink into the soil; plants should be dug after two years and shallowly replanted to keep crown rot under control.
Now is the time to combat petal blight and bud blast in camellias. Clear off old mulch and any debris under the plants. Spray plants with a fungicide labeled for use on camellias. Lay down a fresh supply of mulch, being careful to only add about 2 inches. When flowers start to open, pick off any that look diseased. Don't allow old flowers to fall to the ground. Keep them picked off as soon as they fade.
It's a good time to prune many deciduous plants. Hardy plants such as oaks, elms, maples, sweetgum and other deciduous trees can also be transplanted now. Grapevines, bunch and muscadine, should be pruned while dormant. Bleeding of grapevines is not harmful if pruning is done when the vines are dormant.
Remember to side-dress vegetable gardens with fertilizer every three to four weeks. Use about 1 pound of 8-8-8 per 100 square feet.
Tomatoes may be infested with late blight at this time of year. Symptoms include brown, water-soaked areas on the fruit and yellowing lower leaves that eventually turn brown. Late blight is a problem when there is high humidity and the temperature is between 60 to 70 degrees. Control by using fungicides labeled for late blight.
Citrus fruit must be fully ripe when harvested as the sweetening process stops once the fruit is picked. Many varieties of citrus have a long season in which they can be left on the tree and gathered for use as needed. There is a time, however, when the tree stops caring for the fruit and it may dry out.
Do not prune citrus until after they bloom. The budwood has developed for blooms and new budwood will not form this late. Spray the trees with basic copper fungicide to help control fungus diseases.
Pam Brown and Carol Suggs of the Pinellas County Extension Center/Florida Botanical Gardens can be reached at (727) 582-2100.