Apricots’ major limbs should radiate from trunk

Just a reminder that on Saturday I will give the first fruit tree pruning class at the University of Nevada Cooperative Master Gardener Orchard in North Las Vegas. The topic will be how to lower fruit trees and keep them small to avoid using ladders.

You do not need to register, but orchard volunteers are asking for a $5 donation to help defray some of the costs in educational programming. If this is a hardship for anyone, please let me know at extremehort@aol.com. Class begins promptly at 9 a.m.

After the class, I will post some pictures and general information for those who cannot attend. For more information, visit my blog at Xtremehorticulture of the Desert.

Q: Could you send me a couple of directions relative to pruning Persian lime and apricot? Also, send any schedule of classes on pruning that might help me. I am a chef and have some limited time.

A: I will give you my best shot without seeing it. Pruning is not a hard science and there are a lot of decisions that have to be made that are very specific to each tree.

Apricots fruit on short flowering branches called spurs. It is important not to remove these short shoots.

You will want to open the tree canopy to admit sunlight into the interior. You do this by eliminating the trunk at about 4 feet off the ground.

This should result in about eight or so major limbs that come from the trunk. These major limbs should originate from the trunk starting at about the height of your knee and ending around 4 feet off the ground. Ideally, these limbs should radiate from the trunk so that two limbs occupy about one-fourth of the canopy.

These limbs should radiate in a pattern similar to spokes on a wheel so that they do not shade each other. Spacing should allow at least a foot or more between limbs that originate on top of each other to prevent shading.

These major limbs may have fruiting spurs coming from them, but their primary purpose is to support smaller limbs that have the majority of the fruiting spurs. The smaller limbs should be at a 45-degree angle, as close as possible, from vertical. This provides the perfect angle for creating flowering spurs.

Limbs that grow mostly up or down should be eliminated at their source, leaving no stubs.

As you finish pruning, these major limbs should resemble a fan that radiates from the trunk in a fashion so that they do not shade each other, give balance to the canopy and allow filtered light to penetrate to the interior.

Persian lime is also known as Tahiti or Bearss lime, which is nearly seedless. Regarding the lime, it should be pruned in a similar fashion, but fruiting does not occur on short spurs. Rather, the fruiting occurs on new growth, frequently in the spring after new growth begins to emerge, but it can flower later in the year.

The biggest problem you might have will be protecting the tree from early freezing temperatures and the loss of fruit production because of these freezing or cold temperatures.

Citrus usually does not require as much pruning, so after you get the major structure established on your tree, you will mostly remove growth that is going downward, upward or crossing each other, as well as any broken or damaged branches, limbs or stems. I hope this helps.

Q: In late February, I planted in containers three Hawaiian tomato plants that grew to 3 feet and produced an abundance medium-sized sweet tomatoes. By the end of July, the plants showed signs of dying. Being from New England, I assumed it was the end of the plants' life and removed them from the pots.

A friend told me I should have slightly cut back the plants and continued watering them. These plants would have made a comeback and produced new flowers and fruit during our fall season. Would you elaborate on this subject? I have never heard about tomato plants producing two crops.

A: Tomatoes stop setting new fruit as soon as temperatures get into the high 90s, so you will harvest these early fruits usually until July and then it produces no more new fruit until fall again when the temperatures drop back into the lower 90s.

I often recommend cutting tomatoes back in late summer when they are no longer producing, if you have a warm microclimate in your yard. If you do not have a warm location free from strong winds, you probably shouldn't bother.

It is very touch-and-go when we do this at the orchard since we are fully exposed to cold northwest winds. It just depends on whether we have a warm fall or not. Late summer is when we begin some of our fall crops and it is a good time to plant corn (bet you didn't do this in New England either).

Here we can have two springs, one before summer and one after summer (actually fall but it acts like spring sometimes). I frequently call our summer "Las Vegas winter" since this is the time of year so many things struggle due to heat and lack of humidity.

Winter can be a fabulous time for growing fall and spring crops again if you have a protected location or provide some protection if it is exposed.

Cutting tomatoes back for fall production usually begins in late July or early August. The plants are trimmed to invigorate new growth and reign them in if they are getting too large. A small amount of fertilizer is applied at this time to invigorate new growth.

Foliar sprays are usually best since they don't last very long, but a small amount of quick-release fertilizer (straight nitrogen) will work. Let them grow and begin flowering again and set fruit when temperatures drop. Be careful not to overfertilize.

You should get a nice fall crop of tomatoes. If there is a threat of a light freeze in mid-December (usually), then cover the tomatoes at night. Use a light covering like a row crop cover or old sheet. Remove it in the morning when danger of frost has passed.

If it is projected to be a hard frost, pull the entire plant and hang it in the garage or sheltered area and let the tomatoes ripen on the vine. They will ripen more slowly if not removed from the vine, allowing a more sequential ripening than if you removed them all. Or you can use the green tomatoes.

Bob Morris is a horticulture expert living in Las Vegas. Visit his blog at xtremehorticulture.blogspot.com.