The two-spotted spider mite is a common pest often discovered this time of year on our indoor plants. Spider mites are small, about the size of the period at the end of this sentence. They are not insects; they belong to the Arachnid class along with spiders and ticks. They have four pairs of legs instead of three, and they lack antennae and jaws.

Mites damage plants by piercing plant tissue with their needle-like mouthparts and sucking out sap and cell contents. This results in tiny needle-like puncture marks that, when numerous, give the leaf an overall silver or yellow cast. Upon closer examination, you see fine webbing. This webbing often starts on the underside of leaves. By the time webs have encased an entire leaf, spider mite numbers are high. Unchecked, mite infestations can lead to bronzing of foliage and premature leaf drop.

Two-spotted spider mites are hard to detect at first when their numbers are low. We usually don't notice them until their numbers are so great we see the webs they create. Over the holidays, we tend to pay less attention to our houseplants. They are often moved and bunched together in a make-shift location. Here, an infested plant quickly spreads this pest. Two-spotted spider mites spread through direct contact from plant to plant.

Spider mite infestations are easier to prevent than to control. Most insecticides are ineffective because mites are not insects. In general, mites prefer high temperatures and low humidity. Your first line of defense is to avoid these conditions. Ample moisture and high humidity lowers mites' feeding. Misting of foliage or placing the plant on top of a shallow container of rocks and water helps increase the humidity in the immediate surrounding area.

Never introduce a new plant without some type of quarantine time period to determine whether it is infested. Inspect the undersides of leaves, particularly along the midrib. Check the middle-aged leaves first since mite infestations seem to begin on those leaves. If a plant is found to be infested, the best treatment is insecticidal soap. Read and follow all label instructions, and make sure your plant is listed on the label.

As winter sets in, fruits and berries diminish–and, birds rely more on us for food. Studies have shown that birds with access to feeders survive the winter better than those that do not have feeders. So if you feed birds, be sure to have an adequate amount of food available for them during the coldest periods of the year.

All feeders should be thoroughly washed with a weak bleach solution (1 part bleach to 9 parts water) at least once a year. This cleaning will help reduce or eliminate diseases that can spread at the feeder. Using a feeder with a perch next to the feeding surface will also reduce the chance of spreading diseases because the birds don't sit on the seed while feeding, as they do on a platform feeder.

In addition to food, seed-eating birds also need some type of gritty substance to act as a grinding agent, which aids in digestion. Coarse sand is an excellent source of grit and can be mixed directly with the food. Crushed eggshells also act as a grinding agent and provide a needed source of calcium.

To cut down on cost, buy seed in bulk. You'll also need a tightly-sealed container for storage to keep the seed fresh and to keep out unwanted guests such as mice or squirrels.

Finally, make sure you place bird feeders out of the reach of neighborhood cats!

If you know of someone who would like to become a Master Gardener but is unable to attend the traditional face-to-face training, be sure to tell them about the online training option. The 2008 class runs January 14 through May 9, coinciding with spring semester on the U of I campus.

Applicants for this course MUST have at least some previous computer experience and feel comfortable with navigating the Internet and using email, as well as basic programs such as Microsoft Word.

The 12 major course units include Botany, Soils, Plant Diseases, Entomology, Integrated Pest Management, Herbaceous Ornamentals, Woody Landscaping.

Participants Ornamentals, Grasses, Houseplants, Small and Tree Fruits, Vegetables, and may work at their own pace but should be aware that the course has specific deadlines for homework and quizzes. Students should plan on spending between 8 to 12 hours per week on the course.

For more specific details, contact Monica David, state Master Gardener coordinator, 217-265-5256, modavid@uiuc.edu.

Despite their dormant condition, trees and shrubs have to endure many forms of injury during the winter. Plants are exposed to sunscald, mechanical damage, frost cracks, freezing, desiccation, and salt damage.

Sunscald is caused by rapidly changing temperatures that can kill living tissues beneath the bark. Usually, the south side of the tree is affected due to the winter sun warming the bark. Thin-barked trees and young trees are most susceptible. Expect to find sunscald on maples and fruit trees until they develop thick or furrowed bark.

Mechanical damage results when excessive loads of ice or snow cause limbs to break.

Frost cracks are vertical separations of bark and wood; these separations commonly occur on the south or southwest sides of trees. Deciduous trees are more susceptible than evergreens. Sycamores are notorious for developing this type of injury.

Direct freezing of buds, twigs, or roots occurs primarily during periods of extreme and rapid fluctuations in temperatures. Spring-flowering trees and shrubs, as well as peaches, nectarines, and apricots, are susceptible.

Winter desiccation causes damage to evergreens such as pines, spruces, arborvitae, juniper, and rhododendron. Evergreen plants lose water from their leaves even though they are dormant in the winter. Drying winds or bright, sunny days may increase this moisture loss. When the soil is frozen, plant roots are unable to absorb sufficient moisture to replace that lost from the leaves or needles. Thus, the leaves or needles are injured by desiccation.

Salt damage occurs on trees and shrubs when excessive amounts of salt are used to remove ice.

So, what can homeowners do to help trees and shrubs survive the winter elements?

First, make sure the soil has sufficient water so plants enter the winter months with ample soil moisture. That being said, don't over-water or over-fertilize. Too much water or fertilizer will stimulate growth. You want slow growth because it is usually harder wood and less likely to break. Fast-growing trees are the most susceptible to snow, ice, and wind damage.

Prune out any injured or diseased branches or dead limbs, but do not prune radically. Make sure plants are properly shaped. Avoid double- or triple-leader trees. Make sure branches and trunks have at least a 45- to 60-degree spread. Tighter limbs appear to grow together but actually don't, causing trees to split with wind and weight. Also prune to balance a tree, making sure equal amounts of branches are on all sides and the plant appears symmetrical. Pruning is best done when the tree is young, but it's never too late for corrective pruning as the tree matures.

Finally, tree trunks, especially those of young trees or trees with smooth bark, should be wrapped with burlap, sisalkraft paper, or other tree-wrapping materials to prevent sunscald. These wrapping materials also protect the tree from voles, field mice, rabbits, and other creatures that might look to the tree trunk for food during the winter months. All tree wraps should be removed in the early spring to limit insect damage to the trunk.

And when snowfalls come, use salt sparingly on sidewalks and driveways that are near shrubs and trees.

A Winter Day in the Garden is set for January 26 at the Zwermann Theatre, Lincoln Trail College in Robinson, Illinois.Doors open at 8 a.m., and the program runs 9 a.m. to 3:30 p.m.

Topics include

·Making the Most of Wherever You Are by Jon Carloftis

·Spring in Bloom: The Art of Bulbs and Branches by Daniel Whitehurst (he will make arrangements that will be auctioned off at the end of the day)

·Container Gardens and Grounds by Nancy Clifton OR Dwarf Evergreens by Heather Sherwood

·Using Perennials and Natives in the Landscape by Dianne Noland

Early registration is $35 and includes coffee/snacks and lunch.

Late registration after January 11 is $40.The program is sponsored by

the Crawford County Master Gardeners and Lincoln Trail College.

Call 618-546-1549 for details. Or, log on to

www.extension.uiuc.edu/crawford and click the "horticulture and

environment" tab.