UC Cooperative Extension Ventura County
669 County Square Drive Suite 100
Ventura CA 93003
Monday - Thursday: 8 am to 5 pm
Friday: 8 am to noon or by appointment
Lawn Fertilization and Watering
The following are a few tips that may help you improve the looks of your lawn and be environmentally conscious as well.
Many of the soils on the Central Coast are light and sandy. Fertilizers applied to these soils will leach through the root zone if more is applied than the plant can use in a short time. Therefore, lawns on sandy soils should be fertilized lightly (use the low end of the recommendation on the bag) and often (every 1-2 months) rather than heavy (high end of bag recommendation) and seldom (spring and fall). Next be aware of what you are doing if you use “weed and feed” type lawn fertilizers. Each spring I get calls asking “what can I do about the strange looking leaves on my trees, flowers or shrubs that are planted in the lawn and at its edge?” Remember, weed and feed lawn products contain herbicides that are formulated to kill the broadleafed weeds (sowthistle, dandelion) in the lawn. Many gardeners forget that most trees, flowers and shrubs are “broadleafed” plants. If the weed and feed gets on the foliage or more likely is absorbed by the roots of the broadleaf plant, a reaction will occur. Broadleafed plants will show growth deformities such as curled stems, distorted leaves, deformed flowers or no flowers at all. Plants may be stunted or new growth may wilt and die. In severe exposure cases, the plants may be killed. Remember, the weed and feed is supposed to kill broadleafed plants in the lawn. Bottom line: Use weed and feed products with care and consciousness, especially under trees in the lawn and by flowers and shrubs at the edge of the lawn. It might be better to carefully spot-treat “weeds” in these sensitive locations and use a regular lawn fertilizer.
With the end of the rainy season lawn irrigation becomes necessary. A recent research report indicates that lawn watering should be done in the same way as fertilizing – little and often – especially on sandy soils. Remember, most of the grass roots are in the top 8-12 inches of soil. Therefore, if you wet more than 12 inches of soil during an irrigation, you are wasting water. To keep the lawn looking good, water a short time and often. A good schedule is five minutes a day, every day. The time and duration should be adjusted to fit your yard conditions. The irrigation should best occur in early morning when there is no wind and the air is moist and cool. It has been shown that sprinklers running in the wind can lose as much as 25% of the water. The mist is simply evaporated and carried away in the air.