Field and Garden: Proper watering reduces disease in plants

My African friend taught me a lesson last year about the proper way to water a garden.

I was going down a row of green beans late one afternoon with a watering wand in hand. It was a hot day, and I thought the plants must be enjoying their shower.

My friend came over and stopped me. “Don’t wet the leaves and blossoms,” he said. “Keep the wand low and near the surface of the soil.”

I knew immediately that he was right. Wetting the foliage provides an opportunity for disease to get started.

I followed my friend’s advice and took greater care to keep the water near the base of the plants. Watering this way took more effort, but the results were worth it. The beans remained healthy and produced a bumper crop.

The principle of applying water to soil and not foliage applies to many garden crops, including cucumber, squash and tomato which are especially susceptible to leaf diseases.

Gardeners are also encouraged to water in the morning rather than in the evening. This way, if the leaves do get wet, they will dry out quickly.

Here are some lawn and garden questions that I’ve recently encountered:

Q: How can I control unwanted grass and weeds around trees?

I know some homeowners spray herbicides around their trees, but I’m not a fan of this method. This risk of killing the tree is too great, even if one thinks they’re being careful.

My recommendation is to control weeds with a layer of shredded bark mulch around the tree.

Before putting down the mulch, remove grass and weeds around the tree by hand. Then create a “doughnut” of mulch with the tree trunk in the center of the doughnut hole.

The mulch layer should be three inches thick, and it should stop three inches from the trunk. If the mulch is against the tree, it might promote the decay of the tree bark.

The mulch should extend out at least three feet from the trunk in all directions.

The shredded bark decomposes over time, so it will need to be replenished annually to maintain the three-inch depth.

The benefits of mulch go beyond weed suppression. Studies show that a mulch ring like the one described above can double the growth rate of a tree.

Q: What’s wrong with my apple tree? It’s five years old and still not bearing fruit.

We didn’t have a late frost this year, so that seems to rule out frost damage to the blossoms.

More likely, the tree simply hasn’t matured enough yet to reach the fruit-bearing stage. It’s very common for apple trees to be six or more years old before producing a crop.

Most apple trees sold in North Dakota are grafted to standard root stock. This root stock is very hardy but it delays fruit bearing.

Check the bark and leaves of the tree. If they look healthy, then the advice is to be patient and allow the tree to mature.

If you have questions about your lawn or garden, please contact me in the Extension office (652-2581), [email protected]).