This is shaping up to be a rough water year. In the coming months we are likely to see limited water supply and you should start now conditioning your lawn to put down deep roots.
Frequent, short irrigations develop shallow roots. Plants that don’t need to reach for water won’t be resilient in summer heat. They will need more fertilization as they will only have access to the nutrients in the top few inches of soil. Lawn grass should have roots 12-24 inches deep. Frequently watered grass has been conditioned not to grow deep roots and will demand more frequent irrigation when summer heat sets in.
Watering too long is also problematic. By far the most limiting nutrient in lawns is nitrogen. When you buy a fertilizer, it will have three numbers that represent nitrogen, phosphorous and potassium. The first number, nitrogen, moves wherever the water goes. If you over-irrigate, nitrogen will be taken below the root zone. Heavily watered lawns will require more nitrogen fertilizer to keep them green and healthy.
Your irrigation schedule is heavily determined by your soil texture. Sandy soil requires more frequent irrigation than clay soils. If your grass shows signs of stress before the next irrigation, first try increasing the time you water each irrigation. Your goal should always be to lengthen the time between irrigations for maximum lawn integrity.
To dial in your lawn water needs, follow these steps:
1. Set 3 or more flat bottom cans or mugs with straight sides at various locations on your lawn
2. Turn on your sprinkler(s) for 15 minutes
3. Measure the depth of water in each can and determine the average water depth
4. Match your sprinkler output to the table below and water the number of minutes indicated.