Soil needs amendments to keep its vitality

Q: I have a small lemon tree, about 3 feet high and 5 years old, growing on my patio in a whiskey barrel. It currently has two lemons growing on it due to the fact that a critter ate all the others. It has produced since the second year (up to eight lemons) if the critter does not eat them. However, the leaves on my little tree are very sparse. Is this common or am I doing something wrong .

A: When we grow things in containers or pots we have to be worried a bit about the soil "going bad" over time. So if you are not adding compost or trying to renew the soil in some way, it will start to get depleted or it will lose its vitality.

I assume you are adding some sort of fertilizer to the soil to help the tree, but the addition of just a fertilizer will not be enough. Organic matter will be needed as well. It is probably best once every year or, at the most two, that you remove some of the soil from the container and add composted soil. It is OK if you damage some roots in the process. They will grow back.

My guess is that the soil is starting to become exhausted. If you could replace that soil with composted soil or a soil mix with a good compost in it, I think you will see some improvement .

Pick a spot in the container, take a garden trowel and dig two or three holes about halfway down and replace this soil. When you pick a compost, pick a good one. My guess is that a good one will run you about $20 or so for a couple of cubic feet of compost.

Kelloggs makes some lesser expensive composts that may be OK. Fox Farms makes good compost but it is expensive. Look for Happy Frog or others that are similar when you do this.

Replace more soil the next year .

When containers are used for vegetables or things like strawberries, we normally replace the soil after a couple of plantings. Disease and insect problems accumulate and build after a few plantings. It will help if you can cover the soil in the container with a couple of inches of organic mulch that decomposes as well.

Q: I'm looking to start a small backyard orchard of fruit trees next year here in Las Vegas. I was thinking of about 10 to 12 trees, using the recommended varieties from your Xtremehorticulture blog. I am still in the planning stages and would appreciate your recommendation on whether I should use bare root trees or container trees.

A: Bare root trees are only available during late winter or early spring before the leaves emerge from the tree. Bare root trees are typically small but establish very quickly if planted correctly. Directions for planting fruit trees can be found on my blog .

There is nothing wrong with planting container-grown trees provided they have not outgrown the container. If trees are grown for too long in the container before planting, this can lead to future problems.

Rows of the trees should run north and south so they don't shade each other. However if the trees are planted in a triangular pattern (trees in neighboring rows are offset by half of their planting distance) rather than a square pattern (trees are directly opposite each other in neighboring rows), it doesn't make much difference which direction the rows are running.

The distance between trees in the rows depends on how big you let them get. If you elect to keep them small so that you eliminate ladders for pruning, spraying and picking, then you can plant most of them as close as 10 feet apart. If you keep them smaller than this, they will require more pruning .

Of course, winter pruning will provide you with fruit wood that you can use for smoking or grilling or chip for surface mulch. This chipped wood will not cause more insects or diseases.

On larger trees, like apples and pears, make sure you use rootstocks that help keep them smaller. The rootstocks on my recommended list will do that for you. The rows should be no closer than 10 feet apart.

If you want to get some small equipment down the rows, then I would put the rows no closer than 12 feet apart and you might even consider 14 feet if you are using a small tractor or larger wagons for harvesting.

Make sure you install your irrigation system and predig your holes, amending the soil, before you begin planting. Plant directly into amended soil and thoroughly wet the soil with a hose several times after planting.

Buy trees just before you are ready to plant them. Don't buy and keep them for several days before planting. We all have good intentions but frequently these trees get neglected. When bringing them home, find a shady spot to put them until you are ready to plant .

If some of you missed the opportunity to order some bare root fruit trees for a January or early February delivery to the University of Nevada Cooperative Extension Orchard, you may still be in luck. There should still be some fruit trees left when they are delivered next month . Call the extension help line at 702-257-5555 and leave your name and number and someone from the orchard will get back to you when the trees are available.

Bob Morris is a horticulture expert living in Las Vegas; he is on special assignment in the Balkh Province, Afghanistan, for the University of California, Davis. Visit his blog at xtremehorticulture.blogspot.com.