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Delay grape pruning as long as possible

I finished pruning the more than 300 table and wine grapes Sunday at The Orchard at Ahern in downtown Las Vegas. New growth was just starting on a few of the vines.

I delay pruning grapes as long as possible in the spring to reduce disease possibilities and avoid any late spring frost damage after pruning. Immediately after pruning grapes, consider applying a fungicide to the vines if there were problems with grape bunch diseases last year. Repeat the fungicide application if it rains.

It’s normal for grapes to “bleed” after they have been pruned in the spring. Don’t worry. Water will stop coming from the pruning cuts when new growth appears.

Effective fungicide sprays for homeowners include the copper fungicides such as Bordeaux. Fungicides primarily protect new growth from getting infections primarily through the pruning cuts.

Unlike insecticides such as Sevin or even organic soap and water sprays, which kill insects, fungicides primarily suppress diseases and help keep these diseases from spreading to new growth. That’s why it’s important to repeat it after a rain, which can wash the fungicide from the vine.

Q: I am working on a new project serving middle and high school kids. The idea of fruit trees around their garden area came up, and I’m wondering what trees you would suggest. They will have approximately nine trees spaced on a grid.

A: Make sure the trees are spaced a minimum of 10 feet apart and are semi-dwarf. All fruit trees should be grafted onto dwarfing or semi-dwarfing rootstocks (Citation for stone fruit, M111 for apples, OHxF333 for pears). If you don’t know the rootstock, then the plant label should say “semi-dwarf” or “dwarf,” not “standard.”

Because these are kids and they are normally not in school from June to September, I would think you would avoid trees that produce fruit then. That still leaves you with early producers like May Pride, Early Grande, FlordaKing, FlordaPrince or Earlitreat peach; Flavorosa pluot; and Royal Rosa, Flavor Giant, Katy or Gold Kist apricot. They should produce fruit from late May until maybe early June.

For late-producing fruit trees, I would pick Pink Lady or Sundowner (red) or Mutsu (green) apple; Bartlett, Red Bartlett or Bosc pear, your favorite pomegranate; Flavor Grenade or Flavor Finale pluots; Emerald Beaut plum; and Giant Fuyu or any Fuyu or Chocolate persimmon.

I would suggest avoiding late-producing peach. I would avoid any nectarines because of the scarring of fruit from insects. Nectarines are difficult to produce without spraying for insects. No late peaches because there aren’t any good ones in my opinion. The best peaches are in late June, July and August.

Be careful not to plant fruit trees based upon recommendations from people not living in desert regions. The tree will most likely grow, but it’s more of a question about the quality of the fruit it produces. It’s different. An interesting exploration for these children would be to compare the quality of the fruit produced by their trees with the quality of fruit purchased at the grocery store.

Dave Wilson Nursery online has a harvest calendar that you can download to your computer for reference. The harvest schedule is for central California but is very close to harvest times in Southern Nevada with a few exceptions. Be careful of fruit recommendations from nondesert climates.

Q: I found some black spots at the base of my saguaro. I attempted to move it, and it wobbled back and forth. I’ll be taking it out this spring if you think that is what should be done.

A: The wobbling and appearance of black spots on the outside of the saguaro tell me that it’s probably getting watered too often and the water applied is too close to the trunk. Those black spots or cankers indicate an internal rotting of the tree.

That wobbling is bothersome to me. These plants need to be firmly anchored into the soil if they are to remain upright.

In nature, the roots of the saguaro might spread out eight times its height. That provides firm anchorage in the soil. To get this kind of anchorage, water needs to be applied deep and infrequently and at large distances from, and including, the plant.

That can be done in several ways. One method is to grow other plants coming from the same climate zone at different distances from the saguaro. Irrigation supplied to these plants will be enough to encourage the roots from the saguaro to spread out.

Enough water should be applied about a foot deep for the first couple of years. As the saguaro gets taller, this water should be applied so it percolates 2 to 3 feet deep.

Another method — and one that I really prefer — is to take a hose on a mechanical timer and inexpensive sprinkler and turn the water on for one hour. I would do this on both sides of the saguaro about 6 feet from the trunk with the water reaching the saguaro.

Do it three times: in early spring, once in the summer and again in the fall. The timing encourages root growth of desert plants but avoids the growth of Bermuda grass. If you see some Bermuda growing, whack the top off with a hoe or shovel as soon as you see it. Do this once a week until it’s gone.

You can find out more about this and what to do by Googling “University of Arizona” and “problems and pests of cacti.” Scroll down, and a link should appear that will take it to the publication on how to control diseases of agave, cacti and yucca. Make sure you use a sharp and sanitized knife.

It’s your call on whether to remove it or try to rescue it.

Q: I believe I have a Bears lemon tree. It was growing in the ground, then transplanted to a 22-inch planter last fall. For a variety of reasons, I finally transplanted it to my raised bed a few weeks ago and used the rejuvenate soil mix from ViraGrow. I cut off one-third of the top when moving it, but the leaves are still yellow, and I don’t see any new growth. I don’t believe the tree is dying, but it’s not healthy. Is it the soil?

A: First, not that it makes any difference, but if you have Bears, it might be a lime, not a lemon. That might affect when it’s harvested. The rejuvenate soil mix drains easily provided the hole drains water. If the hole drained water in six to eight hours, everything is fine. Just don’t water the tree every day.

The yellowing and poor growth are most likely from recovery from the damage during transplanting. Yellow older leaves stay yellow even if everything is wonderful.

Watch the new growth coming out. That’s the key. If the new growth is green and not yellow, that indicates the tree is doing well. The yellow leaves will be replaced visually by dark green leaves later.

Make sure you are not watering too often. I am watering established fruit trees with wood chips on top of the soil once a week all during February. This irrigation frequency is to push new growth and fruit production.

If trees were just planted (or transplanted), I water twice immediately after planting and then about twice a week, every three to four days, until new growth appears. Once strong new growth appears, once a week should be often enough until about mid-April if the soil is covered in wood chips.

Make sure the tree is staked solidly in the ground to keep the roots from moving during establishment. I use a 3- or 4-foot-long 3/16 rebar pounded in the ground right next to a new 5- or 15-gallon tree, and the tree is tied to it only for the first growing season. I tie the tree to the rebar tightly with stretchable green nursery tape.

Bob Morris is a horticulture expert and professor emeritus of the University of Nevada, Las Vegas. Visit his blog at xtremehorticulture.blogspot.com. Send questions to Extremehort@aol.com.

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