Printed in the Contra Costa Times on January 10, 2004

Q. What should or should not I be doing with my fruit trees this time of year? I have apples, pear, nectarines and lemon trees.

 

A. Apple and Pear trees should be pruned, removing all damaged  or diseased wood and about 20% of last years growth.  Spray with a dormant oil which will help control San Jose Scale, aphid and mite eggs. Make certain that your pruners are sharp and oiled so that the cuts that you make are clean. Apples bear on fruiting spurs, thickened small branches with fat buds at the apex.  Occasionally gardeners become too enthusiastic with their pruning, removing too many of the spurs, significantly reducing their crop.  If the soil under the tree is saturated, wait till it has dried out for several days before pruning. Control winter weeds, but do not till beneath the tree. Tilling will damage the roots, and impact the stored nutrition for the upcoming new leaves. It is not necessary to coat pruning cuts, and may damage the trees by trapping disease organisms under the coating. This is not the season to fertilize.

 

The nectarine tree should have been sprayed once in December with a fixed copper spray to help control Peach Leaf Curl. The second spray should take place around Feb. 1. These trees need to have about 50% of last years growth pruned out to encourage new shoot growth in the future. Remove any dead or damaged wood, and check for borer tunnels.  Remove mummies (withered fruit that was not harvested that might remain on the tree).  Spray with dormant oil to control San Jose Scale.

 

The Lemon needs very different care.  Pruning is done later in the spring after the danger of frost has passed. The biggest winter issue concerns minimizing potential freeze damage. If you have mulch under the tree, you may want to pull it back so that the soil can warm up during the day-light hours.  Make sure that the mulch is replaced in the spring. If a heavy freeze is forecast,  wrap the trunk of a young tree with a thermal wrap. This can be several layers of corrugated cardboard, several layers of newspapers, or a purchased wrap. Be sure to cover the trunk to an area above the bud union. If a very severe, artic freeze is forecast, you might want to use in insulated sawdust collar. Make a collar 5-6" ( 12.5-15cm) in diameter and place it around the trunk/ bud union. Fill this with sawdust. Anti-transpirant  sprays will provide a bit of protection in less dire conditions, you can build a scaffold over the tree and cover it with a sheet, or decorate  the tree with outdoor lights. Water the tree well a day or two prior to the freeze, and again after the freeze hits. Moist soils hold heat better than dry soil.

 

( Here are the January to-do lists from the Master Gardeners in Contra Costa)

 

Prune dormant deciduous fruit trees except for Apricots. Check ties and stakes.

 

Protect vulnerable plants from freeze/frost damage.

 

Plant bare-root fruit trees, roses, berries, rhubarb, asparagus,  strawberries, artichokes, gladiolus.

 

Prune roses and other summer blooming shrubs. Wait to prune spring blooming plants.

 

Remove winter weeds.

 

Do not walk on wet soils to avoid compaction problems.

 

Prune Sasanqua camellias when they have stopped blooming.

 

Trap for snails and slugs.

 

Design your spring garden. Order seeds if necessary.

 

Visit the California Rare Fruit Growers Scion exchange.

 

Spray dormant sprays to help control aphids, scale, mildew. blackspot, rust. Spray on a windless day when the temperature is above 40F.