Gardening : Drip Irrigation Is Efficient in Times of Drought : Summer planting: A good watering system produces fewer weeds and more uniform plants. But it may take practice to learn how long to water.


We can still plant flowers and vegetables for summer even though we must also save water. We must just be wiser.

It is not, however, a good time to do major work. If one or two new roses, shrubs or trees are needed in the garden, you can probably water them by hand. Be sure to build a hefty watering basin around the new plant so water goes where it is supposed to go.

But, now is not the time to tear out the lawn and plant something else, nor is it a good time to redo entire beds or areas, even with drought-resistant plants. Better to wait for fall and cooler temperatures when there is also the chance of rain to help with initial irrigation of new plantings.

You can plant annuals, such as marigolds, petunias and zinnias, and summer vegetables. The trick will be how you water them, and the solution is probably drip irrigation, which is an efficient means of thoroughly watering only what you want. You do not want to water these plantings with sprinklers. Not only is it inefficient, it will bring up a bumper crop of weeds.


This is, in fact, a good way to learn about drip irrigation, on a small scale, where any mistakes will not affect the entire garden--just summer flowers and vegetables.

Nurseries and garden supply stores are well-stocked with drip-irrigation supplies. Some discount drugstores are offering inexpensive drip-irrigation kits that can be hooked up to the garden hose or hose bib. These are not big enough, or sophisticated enough, to water an entire garden, but they are a start.

Once you’ve developed some confidence in the system, you might feel encouraged to try it on a large scale.

You’ll find that there are some advantages, especially with new, young plants. Since the emitters are placed at the base of each little plant, you water only the plant and the soil immediately around it, so few weeds will sprout in the dry soil between plants. The water spreads as it sinks in so it actually waters a lot more soil below the surface than it does on top where weeds can sprout.

You are also sure of watering each plant, since the emitters can’t miss, and each plant gets the same amount of water, so they tend to be uniform in size.

It takes some practice to get an idea of how long to water. Most systems come with directions that tell you how to figure out how much water a plant needs and how long you must leave the system turned on. But with annuals and vegetables, you can quickly tell when you have not watered enough because they wilt right away, then recover quickly when you correct things.

This is not always the case with other plants used in the landscape. Again, it’s good practice for a bigger system.

Above-ground drip systems will work for things planted early this spring, such as perennials, trees or shrubs. Many people do not like the look of a drip system, objecting to the spaghetti-like sprawl of black pipes and tubes, but these can be hidden under mulch.

A good, thick mulch (3- to 4-inches thick) of organic matter will hide all traces of drip tubing and will help insulate the roots of the plants from the summer sun. It also will slow evaporation--another wise move during a summer of drought.

Or, you might experiment with one of the porous-tubing systems that are buried underground, completely out of sight. These slowly leak water through the sides of the tubing and do not water the surface of the soil, so there is little chance of weeds sprouting. Plants must be placed very close to the tubes, however, if they are to get any water while young. Most of these systems come with good instructions on how to set them up and use them.

So, go ahead and plant some summer color, but pick up a drip-irrigation or porous-tubing kit, along with the petunias.


If you are worried about cutting back on watering because you fear for your fruit trees, here is some good news. Deciduous fruit trees (apples, peaches, plums and the like), according to the University of California, “can survive an entire season, or a whole year, with very little water, but they will bear undersized fruit.”

At this point of the year, it is a good idea to give the tree one thorough soaking, using a large basin or drip irrigation to help the water sink in to a depth of 4 to 6 feet. You probably will not have to water again until late June or July, and trees can go without after that until winter rains come.

This advice only applies to established, mature trees. Young trees need more frequent irrigation.

Thinning the fruit now also will help. Remove half or more of the fruit so the remaining fruit will grow to normal size.

Citrus on the other hand (and most other subtropical fruits) are not deep rooted (their roots are in the top 18 to 24 inches of soil) so they need to be watered at least twice a month. Most people, however, are probably over-watering their citrus, and they are tough plants so it is perhaps better to err on the side of too little. Most citrus are not killed by drought but by deluge--by over-watering.