Caring For Apricots
By Bob Chapman
Apricots in the home orchard provide the gardener with ripe luscious fruits. They can be eaten fresh, dried in the sun or canned, thus providing a year 'round source of food. They are well with the efforts expended to properly maintain them. Following the guidelines below will result in bumper crops of delicious fruit year after year.
WATERING
Over half of the problems gardeners have with apricots can be traced to improper watering.
• These hardy trees need to be watered when the soil six inches below the surface is barely moist. Then supply enough water to wet the soil 2 to 3 feet deep.
• Water (moisture) moves upward in the soil, particle by particle, from the underground reservoirs until it reaches the surface. Moisture not used by the tree is evaporated by the wind and the sun.
• To determine when to water your tree you'll need to use a shovel and a ruler. Dig down with your shovel, then use the ruler to determine the level at which the soil is barely moist. It takes a couple times before you have a feel for doing this but when you do this digging and checking you'll have a good understanding about the movement of moisture in your soil. You can also use an inexpensive moisture meter. These meters are sold in the inside garden department of our stores.
• When the soil has reached the stage when water needs replacing you'll need to add enough water to wet the soil two or more feet deep. If your soil is clay-based you'll need to add about 6 inches of water to wet the soil 2-3 feet deep. Sandy or gravely soils will need about half that amount. Although clay soils take more water to penetrate 2-3 feet deep, these soils will hold moisture far longer as it takes more time for water to evaporate. Wise gardeners note the time between waterings and thus will learn how frequently you'll need to water your trees.
There are three ways to water the trees:
• If possible construct a 6-inch high circular berm under the drip line of the tree and fill the basin formed by the berm with water and let it soak in. This is the method commonly used by orchardists.
• Consider using a set sprinkler and placing it near the trunk and letting the sprinkler run at full pressure for several hours.
• The third method, becoming more favored by orchardists, is drip irrigation. Usually a 1/2-inch diameter polyvinyl mainline is placed in a wide circle under the tree. On mature trees one-gallon-per-hour emitters are spaced an average of five feet apart. Raindrip, a leading seller of drip irrigation supplies, recommends turning on the drip system twice weekly for eight hours each time, for a total of 16 hours per week in warm weather and up to 12 hours, thrice weekly during hot weather. Pick up a free booklet in the plumbing department of our stores for help in planning and installing a drip system.
PREVENTING MOISTURE LOSS
• Prevent moisture loss by spreading a thick, 3-4 inch layer of mulch over the surface of the soil. Using a layer of landscape fabric under the mulch helps control weeds and assists in preventing moisture loss by evaporation from sun and wind. Landscape fabric is found in the inside garden department of our stores. Our helpful sales associates will be glad to show it to you.
• Common mulches are bark chips, compost, redwood sawdust, wood chips, shredded bark and mushroom compost. All are available at our stores in the nursery section or at local rockeries.
FERTILIZING
Feed your apricot twice yearly, in February and after harvesting. Use sulfate of ammonia, 1/2 pound per inch of trunk diameter, with a maximum of 3 pounds. Spread it under the canopy from two feet from the trunk and just beyond the drip line, then rake or cultivate the soil and water heavily to get the fertilizer to the root zone. If too much foliage is produced with this fertilizing schedule cut it down a little in following years. If the foliage is pale green and the tree loses vigor, increase the amount.
PRUNING AND THINNING
• Apricots bear fruit on short fruit spurs formed on previous years growth, commonly called second year wood. These spurs will bear up to 4 years. The goal in pruning is to conserve enough new growth to produce spurs that will replace old, worn-out, exhausted spurs. Prune back all but one leader of last year's growth, then cut the remaining leader to about half, then thin out non-productive, old spurs. See the Sunset "Pruning " for excellent drawings and descriptions on pruning apricots.
• Pruning is done at dormancy. Exceptions are that if the tree suffers from a disease called Eutypa, which kills twigs and branches, prune in August as that is the time when the disease is least likely to spread.
• Thin apricots in mid-spring, leaving 2-4 inches between fruits. Do the thinning after the natural fruit drop occurs. You actually get more fruit when you thin than if you let all the fruit grow.
PESTS
The most common pests are borers, fruit moth (codling moth) and scale.
• Control borers by spraying permethrin from the crotch to the ground in mid-summer (May-July 4th).
• Codling moths are controlled by spraying with malathion two weeks after petal fall.
• Scale insects are difficult to control. Spray dormant trees with horticultural oil and, unless severe outbreaks occur, let the natural predators keep the scale population under control.
• Keep ants from getting in the trees as they "farm" scales and fend off the natural predators. "Tanglefoot" will keep ants out of trees. They can't cross a band of it. Wrap a three-inch-wide band of masking tape around the trunk, making sure that there are no spots that the tape is not contacting the bark. Use a spatula or a paint stirrer to apply the sticky, gooey "Tanglefoot."
DISEASES
Brown rot, blossom and twig blight and shothole funguses are the more common diseases.
• Brown rot, rotting of the maturing fruit, is caused by fungi. Control brown rot with the fungicide Microcop and Sta-stuk at the red bud stage. Do a follow-up spraying 2-3 weeks afterwards and a repeat spraying 5-10 days before harvest.
• Blossom and twig blights can kill blossoms and twigs. This disease is also caused by a fungus and it is closely related to the fungus that causes brown rot. Control the blights following the same schedule and using the same fungicide used for brown rot.
• Control shot-hole fungus (holes appearing in the leaves) by spraying dormant trees with daconil and spray again after petal fall.
• Gummosis (sap oozing) is normal on apricots but occasionally the sap oozing out is a result of environmental stress (poor growing conditions), being hit with equipment and causing damage to the trunk or from borers tunneling into the trunk.
POLLINATION
Most apricots are self-pollinating. 'Riland' and 'Perfection' need pollinators. Use any variety for cross-pollinating these two varieties except 'Reeves.'