Fruit tree pruning classes to begin at orchard

I will be conducting fruit tree pruning classes at the University of Nevada Cooperative Extension Master Gardener Orchard in North Las Vegas. The first class will be Nov. 12. This will be before leaf drop and the topic will be how to lower fruit trees to reduce the use of ladders when pruning or harvesting. All other pruning classes will be conducted in December and January.

I think most of you realize that our economic downturn has resulted in a substantial loss of funding. This includes funding to support the orchard. For this reason, a $5 donation will be asked for each of the classes. All money collected will be used to support educational programs at the orchard. If this places a hardship on anyone, please let me know and we will make suitable arrangements.

Q: Attached are some photos of my semidwarf plum we just planted in September. The left side of the tree seems to be dying. The leaves are all browning. We have it on a drip system along with a few other trees and shrubs, which are all doing fine. We water for about 15 minutes each day. I sent these photos to the nursery and they said it's transplant shock and it should be fine. What is your opinion?

A: After seeing your pictures I do not believe it is just transplant shock. It's true that trees that large, when transplanted, go through a lot of shock. It is always best to buy the smallest container size possible as the tree will catch up and surpass a larger tree due to a lesser degree of "transplant shock."

Transplant shock is when a plant has to "reorganize" and "renew" its root system as it leaves a container in a protected environment like a nursery and is put into a different, usually harsher, environment.

The root system grows differently in a container than it does in the ground. When growing in a container, roots gather where there is the best water/air/nutrient environment, usually at the bottom and sides of the container.

Once in the ground, the best environment for roots shifts and is nearer the soil surface. This results in a reorganization of the roots as the tree adjusts to this new environment. During this shift, new roots grow near the soil surface and older roots that are deeper in the soil will die, resulting in transplant shock. The degree of transplant shock depends on the condition of the plant going into the ground as well as how it was handled at planting .

Now onto your tree and how it was handled at planting. Hopefully you dug the hole three to five times wider than the container. It did not have to be deep, just deep enough for the roots to be planted below the soil level.

Next, hopefully, you amended the soil going into the hole with lots of compost and a starter fertilizer . The plant should be planted the same depth as it was in the container, no deeper. In one of your pictures, the tree appears to be planted fairly deep, but it is hard to gauge from a picture. If planted too deeply, it can kill or damage the tree.

Next, the tree must be staked to prevent movement in the wind during the first complete growing season. Sometimes larger trees that have more severe transplant shock may require a second season. The stake should prevent the movement of the roots in the soil, not necessarily to prevent top movement. This is extremely important on container trees, especially older trees.

I don't think 15 minutes is enough time for irrigation unless you are giving the tree at least 10 or maybe 15 gallons each time.

Thirdly, watering every day is not necessary and may cause a problem similar to what you are seeing. Daily watering is fine in containers but once in the soil there is a lot more soil available to hold water so every other day or even every three days is probably adequate during the summer. When planting in the fall, you probably will get by watering twice a week.

Lastly, the tree will do much better with a thick layer of mulch around it, extending about 3 feet from the trunk in all directions. Keep the mulch 6 inches away from the trunk to prevent it from rotting.

Q: Thanks for the response to my almond question.  I hope it helped some folks. Now I need help on my apricot tree. I notice what appears to be sap oozing from the trunk in a couple of spots. Is this normal? Or should I be concerned?

A: Thank you for sending the picture. On an apricot, yes, you should be concerned .

If you have been following my answers to questions in the newspaper, than you know I am going to chastise you for putting rock around a fruit tree. This should be organic mulch.

Sap coming from a fruit tree does not always mean an insect or borer problem. Sap can also indicate stress. It looks like the tree is on the north side of a wall, if the picture was taken in the morning. So we can probably ignore the chance of sunburn on the trunk.

From the picture, it appears that the tree is relatively young. I think we can narrow it down to three possibilities. Borers or boring insects are a possibility but they usually attack damaged wood due to sunburn.

The other two possibilities are irrigation and how it was planted.

Pull the rock mulch away from the trunk. It is possible to rot the trunk of the tree at soil level if mulch is placed directly against the trunk and the mulch is kept wet. Keep it at least 6 inches from the trunk.

Once the rock mulch is pulled away, next pull the soil away from the trunk. Begin to pull the soil carefully away from the trunk so that you do not damage it. Find the location where the roots begin to come from the trunk. That should be the depth at which it was planted.

If these roots are deeper than ½ inch more than this, pull the soil away from the trunk and keep it away. Planting a fruit tree too deeply can cause a disease called collar rot to begin. This can also cause sap to ooze from the trunk.

The third thing is watering too often. Shallow, frequent irrigations can cause root dieback, which can lead to stress that can lead to sap oozing from the trunk. You should not be watering daily. You should be watering deeply and less often. I hope this helps.

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