Damaged branches can be ‘grafted’ back to health

Q: I trimmed my 2-year-old pomegranate yesterday, but made a rather unfortunate error. Using loppers I'm not used to, I managed to do a lousy job of trimming a branch. To make it worse, I cracked the trunk vertically when pruning. I sent you a photo. This morning I used sports tape and bandaged the poor tree. What, if anything would you suggest I do?

A: From your description it sounded like you had cracked the entire branch, which would have been a tough one to correct. If the crack went all the way through the branch and it was an old wound, then the branch would have to be removed.

From the look of the picture though, it just appears like it did not crack through the entire branch. If that is the case, then it should repair itself.

If this ever happens to you again, remember that time is of the essence. If you can take some tape and immediately press the damaged area back together before it dries out, then it will heal itself. The cracked surfaces will fuse together when held together tightly for a few weeks during warm weather. It's the same idea as grafting.

Grafting puts together two fresh pieces of wood from two different but compatible plants and the woods fuse or grow together. In grafting, or budding, it is important to line up the wood so that similar areas are touching each other, primarily the cambium layer .

Q: I am enclosing pictures of our peach tree that produces a large number of peaches every year. We noticed resin on its trunk. We hadn't noticed it until now. We have been living at this house for two years and this tree was already here. Is that any type of disease or is it normal for this type of tree? When is the best month to prune a peach tree? When is it recommended to fertilize a peach tree?

A: This is damage from boring insects. I can tell because the bark is lifting away from the damaged area. The resin is sap exuded from the damage by boring insects.

The best thing that you can do is to sharpen and sanitize a knife with alcohol and begin to scrape away the dead bark that lifts from the trunk easily and any packed sawdust left by the borer. Remove damaged wood from the tree in the damaged area until you reach healthy wood. If the damage is more than half way or around the limb, you may have to remove the limb.

Paint any exposed surfaces of the trunk and limbs with diluted white latex paint. Dilute the pain with an equal amount of water, or a 1-to-1 mix of paint and water. Apply this white wash to the upper surfaces of all limbs and the south- and west-facing trunk. This will not hurt the tree and growth will emerge from the whitewashed area.

Also, maintain as much canopy or shade on the limbs and trunk as you can buy keeping the tree healthy through appropriate watering and fertilizers.

You should prune peach trees before they begin to bloom, which will be in the next week or so. Fertilizers also should be applied now along with an iron fertilizer. Any fruit tree or rose type of fertilizer will work well on fruit trees.

Q: We planted 13 Japanese blueberry bushes along a fence line approximately four years ago. Our aim was for them to grow as tall as possible. They looked good for a couple of years and continued to grow. These past two years most of them have dropped their lower leaves. We have not trimmed them this past year. They are drip watered once a week for one hour. Some get mostly sun and some get partial sun as they are blocked by a large California pepper in the early afternoon.

Can you give us any idea as to why they are dropping their leaves?

A: This sounds as if it is a soil or watering problem or combination of both. Please keep in mind that Japanese blueberry is a bit out of its climate range here in our Las Vegas Valley. They can grow here but it must be under the right conditions and right exposure.

It may be that these plants will prove to be the wrong plants to use for this purpose along a fence line. The problems you may have to overcome with a Japanese blueberry include alkaline pH, salinity or high salts, low levels of organic matter in our soil, high light intensities, high winds and low humidity.

It is a big risk to experiment with this plant in our valley. In my opinion, they need to be handled much like a Carolina cherry laurel. First of all, consider soil enrichment and drainage. The soil needs to be enriched with compost year after year. If the plants are in rock mulch, they will look very sick in just a couple of years.

Next is the problem of heat. If they are in a very hot location, such as close to walls where there is a lot of reflected heat, the leaves will begin to scorch on the edges and drop from the trees. If these are in a very windy location, you will have similar problems.

Frequently the dropping of lower leaves has more to do with general health problems, which are then compounded by environmental extremes. More simply put, I think your plants are starting to decline in health and our harsh environment is now hitting them pretty hard. I am not sure if there's anything you can do over the long term that will fix this problem.

You can try to correct the problem by adding more soil amendments, such as nutrient-rich compost, around the bases of the trees along with wood mulch. If the lower leaves were lost, then the lower branches may also have died. If this is true, there is nothing you can do to bring these lower branches back .

Bob Morris is an associate professor with the University of Nevada Cooperative Extension. Direct gardening questions to the master gardener hot line at 257-5555 or contact Morris by e-mail at morrisr@unce.unr.edu.