Blue Spruce

Master Gardeners advise that you dig a hole as deep as the root ball and as wide as three to five times the width of the root ball when planting a tree, like this blue spruce.

Need advice on how to grow juicy ripe tomatoes, plant a spruce, or get rid of aphids? Consult the best gardener in your neighborhood, right? Chances are, you’ll receive some sage counsel. But nearly all gardeners, even highly successful ones, use a technique or two that isn’t doing any good. Some, in fact, could be harmful.

Here we will discuss a few gardening practices popular in Northern Arizona and sort out which ones are sound and which ones are merely empty claims.

• Should I use stakes to support my newly planted trees?

Here in my neck of the woods, Timberline, winds reach upwards of 60 mph, so staking is a must, but we remove them after couple of years. In less wind-prone areas staking may be unnecessary or needed only until the trunks are strengthened, about a year. If you leave them much longer, the trunks may never gain their potential girth. Check frequently to ensure cords or wires do not cut into the bark.

Verdict: fact, with care.

• How about using a solution of dish soap and water to zap aphids?

This can be a safe and effective method to kill some insect pests if you take a few precautions. First, select a dish soap that is free of dyes and perfumes. Next, test a low concentration of solution on a small section of the infested plant. One year when I treated a plum tree the concentration of soap in my solution was too high, and every leaf was burned.

Verdict: fact, with precautions.

• Water droplets on leaves act as magnifying glasses when the sun shines, causing burning of the leaves, right?

Wrong. The sun’s rays are simply not that strong. But midday watering may be ill-advised because evaporation rates are generally quite high then.

Verdict: fable.

• When I plant a tree or shrub, I always dig a hole twice as deep and twice as wide as the root ball. Is this the proper method?

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This rule-of-thumb is outdated. The University of Arizona Cooperative Extension advises that you should dig a hole as deep as the root ball, while loosening and breaking up the soil three to five times as wide as the root ball.

Verdict: fable.

• My neighbor claims that painting her apple tree trunks white will prevent a malady called sunscald. Absurd, right?

Sunscald (Southwest Winter Injury), a condition that thin-barked trees develop when exposed to intense sunlight and extreme temperature fluctuations during the winter, is a genuine concern in northern Arizona. It can be prevented by painting the trunk from the ground up to, and or, including some of the lower branches with white latex paint. This will prevent cracking of the bark.

Verdict: fact.

• I’ve heard that I can add sand to loosen up the heavy, clay soil in my garden. Will that work?

For most clayey soils, mixing sand in to loosen the soil is about the worst thing you can do. Adding sand can turn the soil into a rock-hard, concrete-like mixture. The problem is not the clay in your soil but rather the structure. Adding sand will not fix this. Instead, add organic matter such as compost, peat moss or coir (from coconut husks) to loosen the soil.

Verdict: fable.

• I’m converting my lawn into a low-water landscape. Drought tolerant plants don’t need to be watered, right?

All newly established landscapes need to watered regardless of the plants used. When you set out a container grown plant, the root system is no larger than the pot it was grown in. Most plants, including drought tolerant ones, need a consistent supply of water so that the roots can grow into the surrounding soil. Once established, drought tolerant plants do not need much water though they will benefit from monthly soakings during extended dry spells.

Verdict: fable, but partially true once established.

Our motto is “verify before use of any gardening practice that seems just too good to be true.” A good source of information is the Coconino Cooperative Extension, which can be reached at 928-773-6115.

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Cindy Murray is a biologist, elementary tutor and Coconino Master Gardener, and co-editor of Gardening Etc. Hattie Braun coordinates the Coconino Cooperative Extension Master Gardener Program. Gardening questions can be sent to CoconinoMasterGardeners@gmail.com or submitted to the Master Gardener Hotline: 928-773-6115.


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