Advice for the Home Gardener from the Help Desk of the
UC Master Gardener Program of Contra Costa County
Client's Request: I've managed to grow an apricot tree from seed. It's now big enough that it has produced a few apricots in prior years. However, it hasn't produced any fruit now for several years. What is preventing fruiting and what can I do to get fruit?
The apricot tree's lack of fruit production could be due to flower or young fruit damage from weather; it could be due to reduced pollination, also potentially affected by weather; it could be due to tree damage caused by a pest or pests, or it could be a nutrition issue for the tree.
Weather
Fruit trees form their flower buds in the fall. Lack of rain or high winds can damage buds before they blossom. Spring rains or late-spring frosts can also damage or kill buds and blossoms. Apricots in general perform best in climates with dry spring weather. This year we had both late frosts and spring rains in parts of the County. Last year we also had significant spring rains, and prior to that several dry years in succession. So, weather could certainly have had a negative impact on the fruit production of your apricot tree for the past several years.
Reduced Pollination
Pollination issues could also have played a role. Fruit production depends on pollination, which is the transfer of pollen from the male part (anther) of a flower to the female part (pistil) of the same or another flower usually of the same species. Apricots are self-fruitful, meaning that they may be pollinated by pollen from another flower on the same tree, or in the case of apricots, by pollen from the same flower. The transfer of pollen from one variety to a different variety of the same type of tree is called cross- pollination. Although not required, cross-pollination does improve the number of fruit that form on apricots. Pollinators, such as bees, are usually responsible for apricot pollination.
This link to a Penn State University extension website
https://extension.psu.edu/pollination-requirements-for-various-fruits-and-nuts
identifies several factors can affect pollination:
Temperatures below 55-60°F reduce bee activity
Windy and rainy weather can slow bee activity
Presence of other flowers -- the fruit plants generally are poor nectar producers and bees will naturally seek out the best nectar producing flowers
Most insecticides will reduce bee activity -- therefore do not spray them during bloom
Pests affecting apricot trees
Apricots are susceptible to a variety of pests, listed at this link:
http://ipm.ucanr.edu/PMG/GARDEN/FRUIT/apricots.html
These include sucking and boring insects and other invertebrates, and bacterial and fungus diseases. If, after reading the descriptions, you suspect that you have any of these issues, there are controls suggested at the same link and sub-links.
Cultural care
The best prevention is good cultural care. Maintaining a good fertilization program can keep your tree vigorous and help prevent infections. Adequate irrigation will help as well.
http://homeorchard.ucanr.edu/Fruits_&_Nuts/Apricot_Prunus_armeniaca_L/
http://ipm.ucanr.edu/PMG/GARDEN/FRUIT/CULTURAL/apricotfert.html
http://homeorchard.ucanr.edu/The_Big_Picture/Irrigation/
With respect to pruning your tree, apricot trees should be pruned in late summer, since they are susceptible to a fungus infection if pruned during wet weather. Because of this, they should be pruned in August -- after fruit production is complete, and early enough to allow time for pruning wounds to close prior to the beginning of winter rains. Information on pruning apricots can be found at this link.
http://ipm.ucanr.edu/PMG/GARDEN/FRUIT/CULTURAL/apripruning.html
I hope that this information is helpful. If you have any questions about the material in these links, or anything else, please contact us again.
Good luck with your tree!
Help Desk of the UC Master Gardener Program of Contra Costa County (MCW)
Note: The UC Master Gardeners Program of Contra Costa's Help Desk is available year-round to answer our gardening questions. Except for a few holidays, we're open every week, Monday through Thursday for walk-ins from 9:00 am to Noon at 75 Santa Barbara Road, 2d Floor, Pleasant Hill, CA 94523, although we will be moving this spring. We will notify you if/when that occurs. We can also be reached via telephone: (925)646-6586, email: ccmg@ucanr.edu, or on the web at http://ccmg.ucanr.edu/Ask_Us/ MGCC Blogs can be found at http://ccmg.ucanr.edu/HortCoCo/ You can also subscribe to the Blog (//ucanr.edu/blogs/CCMGBlog/)