Mid-summer Irrigation

Question: I dug a hole to plant a new tree and found that the soil was very dry below 3 inches. I am concerned about whether my trees and shrubs are getting enough water with my current irrigation schedule. My sprinklers are set to water 10 minutes every morning. That schedule is keeping my lawn green. If I water longer than 15 minutes, water starts to run off in some sloping areas. What would you suggest?

Answer: You might want to dig in several areas to find if the soil is consistently dry below 3 inches. Then increase the amount of water you are applying. You can program your sprinkler clock to run 2 or more times in succession on the same day. I would suggest that you try running through two 15 minute cycles on Monday, Wednesday and Friday. Turn the sprinklers off on other days (Tuesday, Thursday, Saturday, Sunday). This will give you almost 50 % more water than your present schedule. The 30 minute schedule should reach at least twice as deep (perhaps 6 inches). This will also allow the soil to dry out on top between irrigations. This will reduce the sprouting of weeds in both lawn and beds. Check your soil with a shovel after a week or two on this schedule. This will tell you if water is reaching the greater depth.

We have reached the peak of water use by plants and use will go down from now on as the days get shorter and temperatures decrease. As you gradually reduce irrigation amount, increase the interval between irrigations instead of reducing the length of irrigation time. Go to one irrigation every three days and then a four day interval.

In areas with trees and shrubs, you can increase the length of irrigation time about once a month to get water to the deeper roots. If this is not practical, you could water trees and shrubs separately once a month. Drip and ooze tubes apply water at very slow rates. They can be snaked through a group of shrubs and turned on for several hours (perhaps overnight). A line can be placed around a single tree at the outer drip line. Check with a shovel to see if water has reached 10 or 12 inches deep.

Vegetables for Fall and Winter Harvest

August is a good time to plant vegetables such as lettuce, spinach, mustard, kale, collards, green onions, Swiss chard, beets, and radishes for fall harvest. These are all frost tolerant vegetables and can continue to be harvested after fall frosts. Kale, carrots and parsnips planted now can be harvested during the winter.

Insects and Diseases

Some insects and diseases are worse during hot weather. Insects multiply faster and some diseases grow faster during hot weather. Check your plants more frequently for holes and discolored leaves. Because most pesticides do not kill insect eggs, a followup application should be made about 2 weeks following the first application. By then most eggs have hatched but are not mature enough to produce more eggs.

Two of the best natural pesticides are Neem Oil and Spinosad. Neem Oil is extracted from the Neem tree. It is effective against both insects and diseases. Neem is not very long lasting so application at one to two week intervals may be needed if you have a continuing problem like black spot on roses.

Spinosad is a compound derived from a bacterial species originally found on sugar cane. It is an organic pesticide with uses including cat fleas as well as for agricultural food crops. Spinosad controls a wide range of insect pests including leaf miners, root maggots, borers, caterpillars, codling moth (apple worms), beetles, thrips and many more insects. The word “spinosad” may not be on the main label. You may have to check active ingredient labels to find it. Neem oil and Spinosad are usually available at full service nurseries and garden stores. If you notice a plant problem, feel free to call or email me for advice. If necessary, I will come look at the problem, usually free of charge. I can also apply a variety of different pesticides.

Easy Care Landscaping

There are a number of ways to reduce the amount of time spent maintaining a landscape. There are also ways to reduce landscape maintenance expenses. However, sometimes it requires some investment of time and/or money to renovate a landscape in order to reduce the amount of maintenance. Below are a few ideas and suggestions.


The lawn is the highest maintenance part of the landscape because it requires weekly mowing most of the year plus fertilization, weed control, and sometimes pest control. In order to keep lawns green during July and August, they also must be irrigated regularly. Installing a sprinkler irrigation system is one example of investing to reduce time dragging hoses.

Raising mowing height to 1 ½ to 2 inches will reduce maintenance costs by reducing weed invasion and pest problems. Leaving clippings on the lawn is the equivalent of one fertilization per year.

Granular weed and feed and liquid lawn weed killers are very effective on broad leaf weeds, but do not control grassy weeds.

Ground Covers can be planted in areas where it is difficult to grow grass (shady areas, slopes, unusual shape areas. Ground covers can completely replace lawns with low growing plants which do not require mowing. There are some ground covers which will take a lot of traffic, however, none will take the amount of wear given by active children. Ground covers are more expensive to establish than lawns.

Trees and Shrubs

Creating beds around trees and shrubs not only reduces grass trimming costs, but reduces mower and trimmer damage. Two inches of bark mulch will reduce weeds by 90% or more. Weed barrier fabric (porous woven plastic) is almost 100% effective until weed seeds blow in on top of the bark or other mulch placed on the fabric. Weed barrier fabric can be applied to already existing plantings as well as new ones.

Weed killers such as glyphosate (Roundup and other brands) can be used to kill existing weeds under and around trees and shrubs as long as you keep them off leaves of desirable plants. Casoron is a very effective, season-long granular grass killer and weed preventer. It should only be used around woody plants (including roses and raspberries). Trifluralin (Preen and other brands) is a granular weed preventer which can be used around flowers and vegetables. It lasts for about 6 weeks. Corn gluten is a natural weed preventer which reduces about 80% of weeds

Pruning can be reduced by replacing overgrown shrubs and trees with dwarf varieties which fit the allocated space. Sometimes removing crowded plants will leave enough room for natural growth of adjoining plants. Shrubs and trees can seldom be reduced by more than 1/3 of their normal height. And even this requires yearly pruning by a skilled pruner. Never “top” or stub off large branches of trees and shrubs.

Flowers and Vegetables

Flowers and vegetables require the most intense maintenance because of the repeated hand weeding. As mentioned above, weeding can be greatly reduced by using weed preventers and mulches. Other effective mulches for vegetables include grass clippings and newspapers. The drudgery of hand weeding can be reduced by weeding a few minutes early every morning when it is cool, and by timing your weeding so you are in the shade (weed west side in morning and east side in evening). Weeding is much more efficient while the weeds are small. Special hoes are available which are sharpened on both edges, which speeds up the process.

Replace annual flowers with perennial flowers which do not need to be replanted every year.

Give me a call (360-606-5437) if you would like a free half hour consultation to get specific my suggestions on how to make your landscape easier to maintain.