HG: Homegrown Column February 28, 2009

Do you use dormant sprays on peach, apricot and apple trees? Thank you for your time.
— Jerry

Dormant sprays are something most everyone with fruit trees should use. It’s just cheap insurance.

A dormant spray is simply a horticultural oil with an emulsifier that’s sprayed on dormant plants. Oil sprays are a safe and effective way to control a wide variety of insects, mites and fungus pests on a whole bunch of different plants.

We usually use them for piercing-sucking type insects such as aphid, mealy bug and scale, though they’ll help control any insect that either over-winters on the tree or lays its eggs there.

They also work well for spider mite and powdery mildew.

A horticultural oil works primarily by coating the insect and suffocating it. Because of this, a complete and thorough spray is essential. The insect must be completely covered for the oil to work.

We often mix the oil with an insecticide and/or fungicide to enhance its effect. That way if a pest isn’t completely covered, you can still get good control.

When I do dormant sprays in my yard, I usually mix the oil with lime sulfur spray. The sulfur does the best job of anything on powdery mildew, plus it really knocks down spider mite.

One word of caution: Lime sulfur has been used for decades and is safe (an organic product), but it smells like rotten eggs. 

Always keep in mind that the mixture of oil and sulfur will badly burn plant foliage so you only apply it while the trees are dormant and before any leaves appear.

If you want to mix an insecticide in as well, then I’d use Malathion or Permethrin.

A dormant spray is usually applied in late February to mid-March. You want to spray the trunk, branches and twigs of the plant, being particular about completely coating the plant.

A dormant spray helps reduce greatly the numbers of plant pests that start out in the spring and results in fewer insect and disease problems later in the growing season.

Sometimes people can get confused over the difference between a summer oil spray and a dormant oil spray.

As the name implies, summer oils are applied during the growing season. Around here, you have to be careful about which oil you choose as a summer oil.

Most spray oils have summer oil directions, but they can often burn the plant because of our heat and dryness.

The only oil I feel comfortable using during the growing season is a brand called All Seasons Spray Oil. It’s especially well refined to remove any sulfur residue (that’s what causes the leaf burn). I’ve used it in July when it was 97 degrees and had no burning of the plant.

I have several bare spots in our established lawn. Some are without any growth, others have been taken over by some sort of branching, short weed with many seeds. As far as I can determine, our lawn is perennial rye.
How do I get a head start in filling in these patchy areas of our lawn? How do I treat the weeds? Is it worth the time to pull them out by hand? Can I wait until the irrigation is turned on to seed these areas and then let lawn water take care of the newly planted areas?
— Barb

First of all, I wouldn’t plan on seeding those bare patches until you have irrigation water, unless you’re willing to drag a hose out and hand water them pretty regularly.

You could, however, get a start on prepping the soil now if that’s needed.

If the soil was well prepared and amended before the lawn was originally installed, you may not need to do much to the soil other than scratching it up and leveling it before replanting.

However, if the soil wasn’t well worked, it would behoove you to dig those patches up and incorporate a good amount of compost or Soil Pep.

Gently firm the soil and rake it off smooth and level with the surrounding existing turf.

If you’re seeding, you could do it the first part of April, but again, you’ll have to provide water regularly so the seed doesn’t dry out. Otherwise, wait until mid- to late April until after you get your irrigation water.

Put a 1/2-inch thick mulch layer of a fine organic material, such as peat moss, on top of the seed to help hold moisture. If you’re pretty sure the lawn is pure ryegrass (that’s fairly rare), then seeding is your only option .

If what you have is a mixture of different grasses, then sod becomes an option.

Far and away, the most common type of sod is Bluegrass. There also is a bit of Turf-type Tall Fescue available.

Sod will be easier to establish than seed since it’s not as critical to be Johnny-on-the-spot with water.

As for the weeds, I can’t give you lots of specifics since I don’t know exactly what you have growing there.

What I’d do is pull or dig them out and dispose of them. That probably won’t get rid of them, but go ahead and replant the bare spots. You can deal with the weeds later.

Establishing a healthy, dense stand of grass will help crowd out those weeds, and there are some selective weed killers that will take out broadleaved weeds without hurting your lawn grass.

Don’t plan on doing that until the new grass is well established (a good six weeks after you plant) because new grass seedlings are susceptible to these herbicides.

Dennis Hill is the nursery manager at Bookcliff Gardens, online at http://www.bookcliffgardens.com. Send questions to Bookcliff Gardens, 755 26 Road, Grand Junction 81506; or e-mail .(JavaScript must be enabled to view this email address).


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