Now is time to get your trees ready for winter

Your fruit trees are starting to go dormant in preparation for winter. The leaves of many fruit trees may not be changing color yet. However, you need to prepare your trees for winter.

The main goal now is to slow down the tree’s growth and finally stop growing. The best way to help them go dormant is to reduce the amount of water. Check the stems near the end of the branches to make sure they are not drying up. If they are becoming brittle, then your trees still need to be watered.

Here in the Antelope Valley, we might need to water our trees once a month through the winter to keep the wood hydrated, unless we receive about an inch of rain, each month, through the winter.

Besides slowing down or stopping the water, in the fall, we need to consider a fall fertilization program. Fruit trees require a fall program that is very low in nitrogen and high in phosphorus and potassium.

We want to avoid using high-nitrogen fertilizers, in the fall, because nitrogen makes the plants grow new leaves and branches. This new growth can easily be killed by the first frost of the season. Any growth that is killed by winter freezes results in less growth for next spring.

We are trying to slow our plants’ growth. This is even true for our other landscape plants. You do not want to fertilize your landscape trees, shrubs or ground covers with a high-nitrogen fertilizer until next spring.

The only exception is your lawns. In order to keep your lawns green through the winter, you need to apply a nitrate type of nitrogen fertilizer, once a month.

Three nutrients that are best applied in fall are phosphorus, potassium and sulfur. They are very slow to move through the soil, so by applying them in the fall, we hope that the winter rain moves them into the root zone for new growth in spring. Potassium fertilizers also can also help plants tolerate cold temperatures.

Other nutrients such as iron, zinc, magnesium and manganese can also be applied now to increase the nutrient level of the soil. These nutrients can be added to the soil, or even better, they can be applied to the plant.

If you plan to apply these nutrients directly to the plant, buy them in a liquid chelate form. A chelated nutrient is one that has been added to an activator that allows the nutrient to be absorbed directly by the plant.

Spraying a chelated fertilizer directly on to the leaves of the plant is the normal method for applying it. Spraying it directly onto the tree prevents the fertilizer from being tied up in the soil and becoming unavailable to the plant.

For fruit trees, roses or any plant that loses its leaves in the winter, the best time to apply a chelated fertilizer is at leaf drop. This means when the plant is starting to lose its leaves, spray it. When the leaves fall off, they leave small wounds that the nutrients can enter very easily. I spray the trees with water; if the leaves are easily knocked off the tree, it is in the leaf drop stage.

As soon as the leaves have fallen off your trees, I find it best to spray dormant oil on the trees. It will suffocate insects and their eggs that might be overwintering in the crevasses on the bark. If you had problems with mildew or any other fungal diseases, remove any remaining dried fruit hanging on your trees; we call them mummies. Rake up and remove all the leaves and spray with a fungicide to kill any remaining spores.

For young trees, you can also apply a mixture of white latex paint (water-based) and water — about equal amounts of each to the trunk and lower branches.

A common disease is sunscald, where trunks and lower branches of trees receive too much sun in the winter when there are no leaves on the trees. The light reflects off our light-colored soil and damages the trees.

It is best to prune your trees is late January, but now is the time to remove dead, damaged or diseased branches. We remove them now because it is easier to identify them. When the tree is dormant, it is harder to identify them.