Thomas J. Koske | 7/29/2005 8:44:12 PM
Adequate soil moisture is essential for a thriving landscape. Inadequate moisture can mean the loss of newly planted grass or increased diseases, according to LSU AgCenter horticulturist Dr. Tom Koske.
"A properly designed and operated irrigation system will ensure that the critical factor of soil moisture will be there to sustain healthy plant growth," Koske says.
High-tech irrigation systems of today demand particular attention if homeowners want their lawns to benefit from all the enhanced features. Systems must be programmed to fit the landscape and seasonal conditions.
Set the timer for what you guess the zone may need, and then watch the results. If you want simply to protect your yard from general plant loss, an on-call approach or weekly irrigation will do.
For better watering, take into account soil type, current drought conditions, sunlight, plants, slope and wind.
Soil types have a lot to do with irrigation cycles. Clayey soils require several short, back-to-back cycles because those soils need more water at any one time, but can only infiltrate slowly. When well watered, clay lawns have the capacity to supply moisture longer. Sandy lawns take in water easily, but have a lower capacity to hold water. They need more frequent and shorter cycle applications.
Plant materials in the landscape also regulate irrigation. Some materials have deep roots and drought resistance. These materials need not be watered as often as shallow-rooted species and succulents. It would be best to plant similar materials together and allow for more appropriate irrigation in zones instead of all zones getting the same dose.
When in droughty periods during the hot season, more frequent cycles will be required. Instead of once or twice a week, you may need a third watering. Poorly designed systems will suffer more in drought and will definitely need more irrigation time to make up for its lesser effectiveness.
If you have slopes, it is important to zone the higher areas differently from those lower. High spots will need more frequent watering and low spots will collect water and need less irrigation to avoid disease and root loss. You may adjust run times or the frequency and timing of their cycles.
Shady areas usually do not need as much water, but that depends on the type of plant materials planted there. Contractors should consider this in their designs. You should base these zone needs on the site conditions and plant material needs.
Wind changes everything. It changes the spray patterns and thus the uniformity of coverage. It also accelerates the evapotranspiration, which causes the soil to dry out more and plants to lose more water. Many areas have the reverse of this problem and have dead air space because of walls and larger shrubs. Consider this aspect of the site when allowing for irrigation programming.
More information on lawn care is available at your local LSU AgCenter office. In addition, look for lawn & gardening and Get It Growing links in the LSU AgCenter Web site: www.lsuagcenter.com.
On the Internet: LSU AgCenter: www.lsuagcenter.com/
On the Internet: www.louisianalawnandgarden.org
Source: Tom Koske (225) 578-2222, or firstname.lastname@example.org