Dry soil warms swiftly for early spring greenup

This week, just some ramblings:

If you have dandelions and you want to control them, now is the best time to do it. Once it gets hot they are very resistant to chemical control measures. Chemicals containing 2, 4-D are most effective. Make sure you apply controls early in the morning when winds are light and follow label directions. This chemical easily can drift to other yards with light winds and cause plant damage.

Fertilize most fescue lawns on Memorial Day, Labor Day and Thanksgiving. Heavy applications of fertilizer now applied to turfgrass can overstimulate grass growth and force you to mow that much more often. If you do make an application, make a light one since now are temperatures that fescue lawns just love. Aerate now to encourage deep rooting.

Dormant bermudagrass lawns will respond now if you mow the lawn very short, keep the lawn on the dry side and apply a high nitrogen fertilizer. Bermudagrass likes temperatures in the 50s to begin some growth. Soils that are dry will warm up faster and encourage earlier spring greenup.

Are you using your mulching mower to mulch lawn clippings back into the lawn? The research is plentiful. It is good for your lawn. It doesn't cause thatch to build up, diseases or weeds to spread or anything else bad to happen. The tiny clippings fall back into the grass and aren't tracked into the home. It is environmentally sound. It's even trendy. Golf courses don't bag the clippings on their fairways. You can do it and cut back on your fertilizer applications by half or skip one entire application each year. I still see some of the most expensive properties in town requiring their landscape services to bag their clippings. Why?

No, you don't need weed barriers under rock mulch. The scare tactic being used to sell weed barriers is that if you don't use it then you will be responsible for weeds coming up. Hello? You will be responsible anyway. It's normal for there to be weeds emerging from rock mulch the first couple of years after it is laid.

Besides, weed barriers under rock mulch over time will capture soil that blows onto the property and accumulate it just below the rock and above the barrier. In a few years there will be weeds growing in the soil that has accumulated on top of the barrier. Barriers do not stop bermudagrass and nutgrass, our two worst weeds. Use 2 to 3 inches of rock mulch and skip the barrier.

Tomatoes like the temperatures right now, not too cold and not too hot. They don't like temperatures much below 50F and above 90F. Peppers like it a bit warmer. Bedding plants for summer color should be in by now. If you haven't got them in yet, get them in quick and make sure you use plenty of organic matter in the soil.

Grapes will be breaking bud soon. As the grapes emerge you will see flower clusters emerge from last year's wood at nodes. If these are table grapes, be sure you thin the clusters of berries to about 1 foot apart and then thin the clusters themselves. The cluster also will get larger if there are fewer total clusters per vine. After clusters flower, the berries will begin forming. When the berries in the clusters are clearly visible, cut or pinch off the bottom of the cluster.

The bottom of the cluster will come to a point. Remove the bottom so that the cluster is no longer pointed but more rounded in shape. This will make the other berries in the cluster larger.

Now is also the time when many of our common borer insect pests pupate and fly to find a mate. When they fly and mate, the female will lay eggs on trees, the eggs hatch and a new borer enters the tree and causes more damage.

Nearly all shade trees and many fruit trees are subject to borer attack. It is common to see borer damage on palo verde, mesquite, oak, willow, plum, peach, upright junipers and cypress, pines, cottonwoods or poplars, pyracantha and loquat. Although difficult to prove, quite a few of the borers are imported into the area on infested nursery stock.

If damage is severe, young trees are likely to decline or die. Older trees can usually take some measure of damage over a period of a few years before they die or must be removed. Unfortunately, trees aren't inspected for borer problems until some sign of damage or near-death is seen. At this point damage from borers can be several years old.

To check deciduous trees for infestations of borers, look for small holes, usually 1/4 inch or less in diameter, that have sawdust falling from them or that are oozing sap. Sawdust on the tree trunk, the ground or loose bark should also alert you. Holes with fresh sawdust indicate the immature borer is still feeding inside the tree.

If you find clean holes not packed with sawdust, the adult insect has emerged and is either feeding nearby or looking for a mate.

Evergreens can show similar signs, but the holes may be hidden under globs of pitch or pitch may flow from the damaged areas. Remove the pitch with a pointed object and probe to see if there is tunneling. Clear pitch means the borer is inactive or dead. Dark or cloudy pitch is probably filled with sawdust from an active borer.

Borer damage must be prevented. Once borers gain access, little can be done to control them. Stress to woody plants may be the result of mechanical injury, recent transplanting, overwatering or drought.

Several practices will help reduce borer infestations -- plant trees adapted to the local area; protect plants from mechanical damage from mowers or line trimmers; avoid pruning trees heavily just prior to summertime when light intensities are extreme and potential damage from sunlight is high; keep lower scaffold limbs on trees with thin bark to prevent sunscalding; paint the trunk and crotches of fruit trees with white latex paint diluted with an equal amount of water; pay close attention to watering regimes so that trees don't become water stressed; and remove trees that cannot be successfully treated to kill borers present.