GARDENING: Fruit tree planting will require aggressive pruning

Question: Last year our local nurseryman suggested we plant multiple fruit trees in one hole. We followed his suggestion and in three large holes we have three peach trees, two cherries, one plum and two apricots. I'm somewhat worried that after several years the trees will have enough top weight that the wind will pull them over. They are almost a year old now, and we're wondering if we should consider uprooting a couple to plant in separate holes?

Answer: We have multiple fruit trees in one hole at our Demonstration Orchard in North Las Vegas. Our problem with this technique is that most often, one tree will dominate the others and if you don't prune the aggressive ones back they will overpower the others and you end up with one tree anyway.

We are not all that happy about the three-in-one hole technique, but we have been working with it now for about seven years and plan to see it through a bit longer. I am not worried about them blowing over if you have good water distribution around the trees. You must do some aggressive pruning to keep them balanced.

I am avoiding whether to tell you to move them to new holes. If you don't have the space, keep them in the same holes. If you have room, move them so they can have a space all to themselves. Fall would be the best time to move them.

Q: I bought a Leptospermum and planted it this spring. After talking with you, I found out it is Leptospermum scoparium.

A: There are about 80 Leptospermum out there, so finding out which one helps a lot. This plant is one of the Leptospermums called the Australian tea tree although it probably originated out of New Zealand. This one is an evergreen shrub that reaches about 10 feet tall with profuse white, pink or red flowers depending on which variety you have. Although it could be considered xeric, it is not a desert plant per se and requires moderate amounts of water.

The information I have is that this plant is most likely sensitive to freezing temperatures and it will be lost if temperatures dip below about 30 F.

It does have potential for invading into garden areas that are irrigated. It is recommended for USDA hardiness zones 9 - 10 or Sunset zones 14 - 24 and 26. Prune it after flowering in early to mid-summer. It may not recover from heavy pruning.

Q: Is it too late to prune fruit trees?

A: No. This should have been done earlier, but you could do it now. Pruning done now should be light pruning, that is, no major limb removal. Wait until next winter for major limb removal.

Get rid of any crossing or broken limbs.

Remove any limbs that are growing too close together but don't leave large openings for the summer sun to enter and scald limbs. This can be a problem if you are opening a fruit tree up in a method called "open center" pruning. In our climate, this can lead to sun scalding of the branches and invasion by borers. Try to keep the trunk and large limbs shaded.

Q: What should I use to fertilize my fruit trees?

A: You are trying to grow leaves, new stems to support foliage, set flowers for next year and enhance your fruit production. This means you need to apply nitrogen, phosphorus and probably potassium for general plant vigor and health.

I would suggest a balanced fertilizer such as a 16-16-16 or 20-20-20 if you aren't opposed to mineral fertilizers. You should always be adding some sort of iron fertilizer, usually as a chelate. This can be the 138 iron to the soil or other chelates as a foliar spray when the leaves appear.

Organic fertilizers should have a good balance between nitrogen, phosphorus and potassium. Manure sources are always rich in organic acids and natural chelates that help to keep the minor nutrients available to plants. Mulch these fertilizer sources on the soil surface and water.

Q: How do I move plants from one part of the yard to the other?

A: Many people want to move trees or other plants to other parts of the yard. Your chances of successfully moving a tree depends on three things: the age of the plant, its health and how long ago it was planted.

The older and larger the plant, the less likely it can be moved successfully. The longer it is left in the ground, the less likely it can be moved successfully. If the tree is in poor health, its chances are slim. General rule of thumb would be that if the tree has been in the ground over three years, don't move it without using a professional. Now is a good time to start playing with the system while it is relatively cool yet. First let your lawn dry out from the last irrigation. This should be dry enough so you start to see several dry spots show up in the lawn. They will look like gray green patches and the ground will be hard under your feet. Push a long screwdriver into these spots and note how hard it is to push into the lawn.

Next, turn on a valve for the lawn for 5 minutes. Wait 10 minutes or so and push that screwdriver in the ground. Note how deep it will push easily. This represents the depth the water traveled into your lawn/soil profile. Run it for another 5 minutes and do the same. Do this until the screwdriver easily pushes into the lawn a depth of 10 to 12 inches.

For most popup spray sprinklers this will be about 12 to 18 minutes total, but depends on the irrigation system you have and the soil type. This length of time is the number of minutes you need to run this valve each time you water. This can be split into two or three applications if it runs off of the lawn or begins to puddle in spots.

By the way, this represents how long you always operate this valve each time you irrigate. The only thing you change during the year is the number of times it comes on each week.

The second thing you need to determine is how often you need it to come on. This will vary with the soil, type of grass and other factors. If you let your lawn dry out until the next irrigation this will tell you how many days to wait between applications. This may be anywhere from three or four days to five days this time of year and your situation.

By the time summer is here, you will probably be watering every day when it's hot and windy, but in winter this could be as little as 7 to 10 days apart if it's a fescue lawn.

Bob Morris is a horticulture specialist with the University of Nevada Cooperative Extension.


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