WATERING WITH TUBING EMITTERS KEEPS YOU FROM GETTING HOSED.

Byline: > JOSH SISKIN

I recently returned from a visit to Jerusalem, which like L.A. has a climate that offers a broad spectrum of horticultural possibilities.

In both Jerusalem and L.A., you can grow lemons and apples, loquats and olives, trumpet vines in lavender, pink, orange or red, and bougainvillea.

A major difference between the two cities' gardens is the way water is delivered. In Jerusalem, you seldom, if ever, see a sprinkler. Instead, drip irrigation tubing is everywhere.

Drip emitter devices snap onto plastic tubing and drip water at a rate that is 50 to 100 times slower than the rate water is sprayed through conventional sprinklers.

A drip emitter will deliver in one hour the same amount of water delivered by a conventional sprinkler in one minute.

But emitters are known for clogging and breaking, which means they require constant maintenance. If your drip emitter system is connected to an automatic timer, you might go away for several days during the summer thinking the watering of your plants is secure, only to return to find that, due to clogged emitters, some of your plants have died.

Israel's irrigation technologists have all but solved the problem of clogged emitters. The user no longer has to worry about snapping on emitters because they are already there.

The latest drip irrigation tubing, which is about a half-inch in diameter, has in-line emitters that are, at first glance, invisible. However, upon close inspection of the tubing, small holes at 12-inch intervals are revealed. There are no breaks in the tubing since emitters have been hidden within the tubing during the manufacturing process.

These seamless in-line emitters rarely clog, unless the water contains salts or sediment, in which case a small filter is installed at the head of the line.

You should be able to find drip tubing with in-line emitters, as well as filters, at most irrigation supply outlets and home centers.

Aside from saving water, drip irrigation improves the health of certain plants by keeping water off of their leaves. Roses, for example, are highly susceptible to powdery mildew and will welcome drip irrigation as a measure to prevent development of this common foliar fungus.

Beneficial insects 

I have not used any insecticidal sprays in my garden for many years, and as a result, insect pests do not persist for long when they do happen to show up.

Biological control has asserted itself as beneficial insects such as praying mantids, assassin bugs, green lacewings, lady beetles, ground beetles, and hover flies rule supreme. Most insecticidal sprays, even nontoxic insecticidal soaps, will keep beneficial insects away in the process of eradicating harmful ones.

The main pillar of biological control is patience, as beneficial insects do not establish their presence overnight.

The aim of biological control is, as the term makes clear, control of garden pests, as opposed to their eradication. You actually want pestiferous aphids, thrips and mealybugs to occasionally appear. How else will your beneficial insects feed themselves?

In designing a garden that is friendly to beneficial insects, it is useful to plant a wide variety of plants, up to 20 species per 100 square feet.

With some plants blooming every season, you will have a constant supply of the two food sources -- nectar and pollen -- that insects require.