Joan Swenson: Fruit tree pruning is the pits if you don't know what you're doing
| Monday, Dec 08 2008 06:01 PM
Last Updated Friday, Mar 27 2009 01:51 PM
An apricot is not a cherry. And a peach is certainly no plum.
If you’ve got apricots, cherries, peaches, plums or any other deciduous fruit trees, the season has come when you must prune. But you have to know precisely which wood to prune and which wood to leave behind if you want to have fabulous fruit next summer. The amount and type of growth removed depends on the tree type.
Generally, deciduous trees need pruning to reduce their size — who wants to climb a ladder to harvest fruit? — and to either encourage or discourage fruit production next summer.
I bring reference books out into the yard to prune fruit trees because I want to do it right. But an even better place to start is with a free lesson in fruit tree pruning from true professionals.
The University of California Cooperative Extension’s fruit tree pruning demonstrations are next week. Retired farm adviser Mario Viveros and current farm adviser John Karlik will be teaching how to prune from noon to 1:30 p.m. Dec. 16 and again from noon to 1:30 p.m. Dec. 17 at the extension offices, 1031 S. Mount Vernon Ave.
The farm advisers will show how to prune apricot, peach, nectarine, apple, almond and cherry trees, plus grape vines, at the orchard east of the main building. Bring pencil and paper to take notes, plus a camera to take pictures to help remember what to do later.
Remembering what to do and feeling confident that you’re doing it right is a big part of pruning. It’s not easy to stand out in the fog, lopper in hand, and make important choices, which is exactly what fruit tree pruning is all about. Some trees produce fruit on new wood, which is the growth produced last summer, while others produce fruit on older wood.
To limit the amount of fruit on an extremely productive apricot tree, remove lateral spurs that live and produce for several years. Apricot trees will not mind heavy pruning. Peaches also benefit from heavy pruning and you can remove 70 percent to 75 percent of last summer’s growth, heading back remaining young growth by a third.
However, plums only need about 20 percent of wood removed each winter, leaving the stubby spurs on older branches to provide you with next summer’s sweetness. Cherry trees? You mostly leave them alone.
Sunset has good pruning guides, but a great little guide is “How to Prune Fruit Trees” by R. Sanford Martin, which I bought years ago at White Forest Nursery. It’s not fancy, and it’s not even in color, but its line drawings are perfectly helpful. The University of California also offers great online publications and information. Try this link to the publication, “Fruit Trees: Training and Pruning Deciduous Fruit Trees” and print pages as necessary to take out into the yard when you prune: http://homeorchard.ucdavis.edu/8057.pdf.
ORANGE SEASON
We have picked and started eating our first navel oranges, which will stay nicely chilled on the tree for many weeks. If you pick an orange and it’s sour, it may be because you are picking Valencia oranges, which ripen in late winter to spring. Check your fruit — if your fruit has a nice little navel button on the bottom, it’s time to start sampling and picking.
