Benefits of Deep Watering
Lawns can survive on water twice per week
Deep watering works! The pictures below show 4 projects within a block of each other, one month after watering was restricted to two days per week in Los Angles. The two projects on the top show projects that Garden View maintains and has trained the roots to grow deep. The bottom two are competitors whom obviously had not gone through the process of deep root training.
After new plantings have sent out roots and are established it is strongly recommended that you encourage and train the root system of your plants to grow deeply. Everyday watering is one of the most common mistakes made. In 32 years of business I’ve observed the results of everyday watering thousands of times (literally). Our company has been hired on many occasions to correct the results of everyday watering. I have also been a featured speaker on several occasions to landscape professionals, garden clubs, and concerned groups especially during the drought several years ago.
Garden View Deep Root Trained Projects
Competitors' Projects one Month after Water Restrictions
Simply stated encouraging deep root growth is universally accepted as good horticultural technique. When you water everyday the roots have no need to go deep for water because they have what they need without the effort of growing downward. When you water daily the subsurface becomes saturated and no oxygen or bacteria can grow. This can kill existing roots and cause fungus and disease. The new roots we are trying to grow deeply into the ground will not grow down into the over saturated soil. When it gets hot out the surface is the first place to dry out. Even though there is water deeper in the ground the grass or plants dry out because their roots are only on the surface and not tapping the deeper water. This is when many people get caught in the Catch-22 situation; “If I don’t water the plants or lawn daily they dry out, if I water daily the roots don’t grow down.” Again, shallow roots create this problem.
One of the biggest problems of over-watering is that trees don’t develop deep root systems and the roots of older, more mature and larger trees may come to the surface looking for air. This can cause trees to blow over in the wind and will encourage more problems with roots and concrete driveways, walkways and other surface root problems. This problem is much more pronounced in pour draining soil. In addition to the shallow root problem the wet boggy soil reduces the stability of the trees in the wind even more. In well draining fertile soil young trees (especially with fertilizer tablets installed) can grow too fast making them leggy and weak.
Another aspect of daily watering is that it encourages weed growth. Weeds (especially crabgrass) generally grow in the top layer of the soil. All seeds (including weeds) need constant moisture to germinate. If the top layer of soil dries slightly the weeds can’t get started but the grass or plants can survive off the deeper roots (unless all the roots are at the surface from daily watering). A weaker grass also provides less competition against weeds.
Pink Rot in the crown of Palm trees is often started and or aggravated from the humidity caused by the constant water. Oak root fungus in Oak tress and crown rot in trees and plants is either started from or exasperated by watering too often. When the ground is saturated worms and grubs often come to the surface; sometimes raccoons, skunks and other critters will dig up grass and ground cover looking for this food.
In fall and winter the roots are still growing but the top of the plant is growing minimally. This is the best time to encourage deep roots by watering as long as reasonable and as seldom as reasonable. When the surface soil gets a little dry the roots start growing downward looking for water. During fall and winter we have less chance of stress on the plants from under watering because the weather is usually favorable (less hot days and less drying winds causing wilt in the plants).
Encouraging deep root growth is a balancing act that is complicated by many factors including but not limited to new landscape, soil types, existing roots from trees and shrubs, plant types, plant groupings, prior watering techniques, sprinkler systems, shade, sun, slopes, drainage systems, changes in the weather and numerous other issues. Water penetration depends on soil. Sandy soil absorbs water much more quickly than clay soil, loamy soil falls in the middle. Check your soil for absorption. Several short watering periods done the same morning are more efficient in most cases than a single long watering. Instead of having for instance a 10 minute watering time change the watering time to 3-4 minutes and do three start times for each cycle one after another.
The key is to water deeply enough that the roots grow downward for the water. Be careful though, if the plants are allowed to dry out too much the minute root hairs (feeder roots) may die setting the process backwards. Please understand this is a process you can not just cut back on how often you water, you must slowly train the roots to grow down for the water.