Calendar of Operations for Fruit Trees in the Eastern Mojave Desert

I promised my friends at the last fruit tree workshop on pruning that I would publish a calendar of operations for fruit trees in the Eastern Mojave desert climate. This is at a 2000 foot elevation. Elevations lower than this will be earlier and elevations higher will be later. It is up to you to make some adjustments but I will post something about what the fruit trees are doing so the calendar can be shifted to a different calendar date. These are not exact dates but can vary two or three weeks either way.

December – January. Fruit trees have no leaves

 Dormant winter pruning

 Pruning of the trees including any major structural changes including removal of limbs with saw or loppers and hand shears. Sharpen and disinfect pruning equipment at the start of each pruning day. More often if diseases are suspected.

Winter insect control

Spray oil application to fruit trees for prevention of outbreaks from aphids, scale insects, mealy bugs and spider mites.These spray oils are marketed under several brand names including Horticultural Oil, Horticultural Oil Spray, Dormant Oil, Ultra Pure Oil, Dormant Spray, Dormant Oil Spray, and others.Two examples are below.Sprays are applied to the trees following label directions after pruning and include all branches and the trunk down to the soil. All weeds are removed. All fruit is removed from the tree and picked up off the ground.

 Fireblight 

Fireblight is a horrible bacterial disease that is commonly controlled through pruning or even tree removal in severe cases. If there was fireblight in fruit trees the previous year, you might see remnants of this disease while you are winter pruning of Asian pear, European pear, apple and quince. If suspected, disinfect pruning equipment BETWEEN each separate cut on the same tree. If severe, remove the tree. Immediately remove infected wood from the property.

Fertilizer application - Two weeks before peach growth begins 

Complete fertilizer mineral fertilizer application or compost application. Fertilizer stakes, fertilizer injectors, mineral fertilizers, guanos, fish emulsion, rich compost, many different fertilizers exist to use or put together your own concoction. Use last years growth to tell you how much to apply for the current year.

Use mineral fertilizers or compost that you know is rich in nutrients

Iron fertilizer application - Combined with a fertilizer application

Apply iron fertilizers to the soil for season long control of yellowing due to iron chlorosis. Most iron fertilizers will work but the best all around iron fertilizer contains an iron chelate called EDDHA.

March - May - Fruit trees have finished flowering and small fruit are developing

 Limb Spreaders

Limb spreaders are used to increase the angle of attachment of a small limb or branch to the tree. The best angle of limb attachment for growth and fruiting is about 45 degrees from horizontal. Limb spreaders can be used during winter pruning but there is a risk of splitting limbs and branches. These limbs and branches are much more supple and easier to bend to a 45 degree angle after new growth starts.

Fruit Thinning

Removal of fruit from peach, plum, apple, pear so that remaining fruit gets larger. Remove extra fruit when they are the size of a thumbnail.

Summer Pruning

Remove unwanted growth from fruit trees before this growth gets big. Redirects energy and nutrients into fruit production, helps keep fruit trees smaller and reduces the amount of winter pruning.

May - First apricots and very early peaches are beginning to ripen

Pheremone traps

This is the time when the first pheremone trap for codling moth and peach twig borer (other insects if you have them and there are pheremones for them) are placed in the fruit trees to catch the first flight of these pests. Getting some insects under control very early will reduce populations of them later. First catches are used to time insecticide sprays for best control and reduced pesticide use (IPM). It can also be used to time the deployment of traps for mating disruption.

 Fireblight

 Fireblight is an insidious disease of Asian pear, many European pear, apples and quince. This is when this disease first appears if it was not present before this. Cut at least 12 inches below where it is visible. If the infected limb dies to the trunk, remove the tree.

General insect control

Patroling and inspecting fruit trees on a regular basis (at least once a week) and inspecting fruit and leaves (bottoms and tops of leaves) helps identify if other pests and diseases might be a problem.

Harvest - May through December

The rest of the year is focused on protecting what you are growing and harvesting fruit. This requires frequent tree inspection and watching for insects, diseases, irrigation problems, mulch renewal, borer removal, etc.