With the holidays approaching, our thoughts turn to the quality time we will be spending with family and friends. As gardeners, our activities have dropped off with the temperatures, but there are still a few maintenance activities we need to consider as cold weather approaches.

 

Through this month you may see some light cold damage on tender plants. Do not prune out this damage now; it is better to wait until warmer spring weather returns. If you have plants that are only marginally adapted to temperatures in the 20s, such as hibiscus, citrus, bottlebrush or powderpuff trees, now is the time to prepare for those low temperatures. Constructing frames around these plants, that can later be covered with plastic sheeting is one method of cold protection.

You can also protect the plant by having clean builder-grade sand with which to mound their lower trunk area if a hard freeze is predicted. This will protect the renewal buds. These will be needed for the plant to resprout if cold freezes the trunk. Once a plant is mounded, leave the mound in place through the winter unless we experience temperatures in the 70s for three weeks or more. At that time it would be necessary to pull the sand back to prevent rot of the trunk area. Remove the sand from the area altogether rather than just spreading it over the roots of the plant. The latter would lead to root problems. Do not place the mound around the cold-sensitive plant until you really have to.

One plant species that seems to be of extra special concern around freezing temperatures with homeowners in our region is citrus. First of all, choose more cold-hardy varieties such as kumquats or Satsuma mandarins as they are the most cold-tolerant. Plant your citrus in areas that protect them from the north and northwest winds. Bodies of water can also help moderate the temperature if the tree is planted on the south or southeast side.

After planting, mounding can be a good practice for protecting the graft union of the tree. Like with the cold-sensitive plants mentioned earlier, place sand or weed-free soil over the lower trunk of the tree except this is done all the way up to the lowest branches. Remove this soil when the threat of cold is over as it can lead to root rot issues if not done properly. A tree can also be covered with frost cloth to protect against frost but is less effective against hard freezes. Remember to remove this covering as temperatures rise because the warmth within the covering can cause the tree to break dormancy. A single, incandescent light bulb can usually provide heat if you want additional cold protection.

Finally, on the day when cold weather is expected at night, water early in the day. Wet soil holds more heat during the day than dry, giving you a little extra root protection from cold.

However, remember to not run your irrigation system during a freeze. Building codes require pipes to be buried deep enough to survive the cold temperatures so this is unnecessary and a waste of water. One tip is to make sure that your hoses are turned off at the spigot, as water left under pressure can freeze, expand, and split the rubber inside.

Poinsettias are now in the stores and can be an excellent household plant through the holidays. However, a little due diligence is needed before buying a plant. Make sure to check the specimen for pests, mainly the whitefly. If when handling the plant you see small white insects flying around, this means an infestation and you will not want this plant as it will decline quickly and the insects could potentially invade other household plants.

If you find a poinsettia that meets your fancy, you’ll want to keep it looking nice through the whole holiday season but care is critical. The best place to locate a poinsettia is right beneath an end table lamp where it can get a minimum of 12 to 14 hours of light each day to supplement room lighting. Without this, poinsettias often drop most of their leaves. Poinsettias are also very water-sensitive, preferring a dry soil. Check for moisture every two days and water if it feels excessively dry or shows signs of wilt but too much water will also cause the plant to quickly die.

THINGS TO PLANT THIS MONTH

Vegetables: Cauliflower, beet, broccoli, Brussels sprouts, cabbage, carrot, Chinese cabbage, collards, kale, kohlrabi, leek, onion, parsley, mustard and radish.

Herbs: Parsley, Thyme, sage, dill, fennel, garlic, comfrey and cilantro.

Annuals: Petunia, pansy, snapdragon, lobelia, alyssum and viola.

Bulbs, tubers or rhizomes: Agapanthus, amaryllis, Aztec lily, calla lily, hurricane lily, kaffir lily, paper whites, shell ginger, spider lily and zephyr lily.

Wayne Hobbs is an extension agent in environmental horticulture for Clay County.