Drip irrigation scheduling for young lavender/low water plants
Larry (Los Angeles, 10a, Sunset Zone 19)
7 years ago
last modified: 7 years ago
Hi all, last winter I planted a couple dozen young lavender plants on a relatively high slope in my yard. The lavenders (and other plants like rosemary) grew well on the occasional days where we'd get a heavy rain, but no other supplemental watering. Now that it's the dead of summer, and we haven't gotten a centimeter of rain here since May, I can't keep up with hose watering these bushes. I have set up drip lines on that part of the yard, but I'm still deciding on what flow rates to use for the emitters and drip irrigation schedule.
My understanding is that young lavender plants are not particularly drought tolerant and need regular watering for the first 2 or so years for establishment before they can truly become drought tolerant. That said, to encourage establishment, my understanding is that these young shrubs need to be irrigated infrequently but deeply. With these shrubs planted on a slope, In my experience, it is not possible to deeply water clay soil, especially on a slope. The soil becomes impermeable after a while, and all the water just runs down the slope.
My question is, do I risk killing lavender through root rot by running drip irrigation frequently but watering shallowly (say 4 GPH emitter per lavender running for 15 minutes, 2-3 times a week, which is 3 gallons per week)? My understanding is if irrigate lavender shallowly, I risk not only losing it to root rot, but if it does survive, it won't establish very well as most of the roots will be close to the surface and it will demand this irrigation regime to survive. Sorry if the post is a little verbose.
Am I completely off here? Any advice or comments will be greatly appreciated.