Leaf and twig litter from garden and landscape plants should be cleaned up and disposed of. If you have a compost bin, the litter can be used to your advantage to make compost. If not bag it up and throw it away. Getting rid of the litter will help reduce future insect and disease problems thorough the oldest control method known: sanitation!

If certain garden plants have been badly infest with insects such as mites, whitefly, or scale; throw them away. Proper composting will kill these pests, however, composting is not always thorough and these pests could reinfect the garden next spring.

Cleaning up weeds also provides sanitation. More importantly, if you eliminate the weeds you'll get rid of weed seeds that could germinate later this Winter. Many unwanted plants sprout each year, these plants are called "volunteers". They may or may not be true weeds. Brittlebush and desert marigold are desirable wildflowers but may become a nuisance as they pop up in uncontrolled locations in the landscape. Others like fountain grass and desert broom are truly invasive and should be eliminated when detected.

Spent flowers and flower stalks should be pruned off. Plants like penstemon, salvia, hesperaloe, bird-of-paradise, yucca and others with dried stalks of spikes can be pruned. This grooming process keeps plants healthier and more vigorous.

Winter dormant perennials, such as Calylophus, Helianthus, Rudbeckia and ornamental grasses can be cut back to near the ground. They will regrow in the spring, producing new shoots from the basal portion of the plant.

Dead wood and broken branches should be pruned from evergreen trees and shrubs now. Be careful, however, not to prune branches that just look dead. Some freeze damaged plants, such as bougainvillea and lantana, will probably recover next spring. The easiest way to tell if a branch is alive or dead, is to scratch it with your thumb nail or a sharp knife. Live wood will reveal green sapwood beneath the bark, while dead wood will be brown throughout.

Mesquite trees often have dead twigs at the ends of the branches. A small gray beetle, called the twig pruner, is usually responsible. The beetle cuts a perfect ring around the twig, and everything from that point out dies. The beetle's purpose is to lay it's eggs in the outside edge of the cut. If these twigs remain on the tree, or fall under the tree and is not removed, the eggs hatch the following spring and the process starts over. If these twigs are pruned out of the tree just below the cut ring or picked up from the ground, the damage will likely not occur next year.

Besides cleaning up, it's also a good time to dress up the garden with additional mulch. Organic mulches are great for plants. They help conserve moisture, control weeds, moderate soil temperatures, and increase organic matter. Because they decompose over time, new mulch needs to be added to maintain a layer 3 to 4 inches thick. Forest mulch, chunk bark, and shredded wood are some of the best types of organic mulch available at garden centers and nurseries. Rock mulch too, needs a top-dressing of additional stone from time to time. No one knows how it disappears, but it does!

Cleaning up garden debris, pruning and grooming plants, and adding mulch are important Winter gardening activities. Accomplishing them now, will afford you more time this coming Spring for the really fun stuff: planting!

Written by John Begeman, College of Agriculture and Life Sciences, the University of Arizona 626-5161.  Material originally appeared in Arizona Daily Star gardening column, on January 17, 1999
Return to index