Posts Tagged: water use
The first week of December is California Healthy Soils Week. To help "celebrate" the occasion, I was asked to give a lecture on some tips to keep your garden soil healthy. If you're the type that likes to watch videos, then you can watch the recording. (It's about 1 hour, including the questions at the end.)
If you're like me and like to get the short, bullet-point version, here it is.
Dustin's Healthy Soil Tips:
- Know your native soil (Try this link!)
- Make permanent paths
- Treat beds like beds: don't stand or walk in them and keep them covered—with mulch
- Add organic materials like compost
- Rotate crops; be sure to include cover crops
- Till gently; here's an article to learn more
Originally published on the Backyard Gardener blog (Dec. 16, 2020):
I hope all of you and your loved ones are staying well and healthy as the pandemic continues. Involving yourself in outdoor activities is not only a great way to escape 'cabin fever' and improve your physical health but it is also good for you psychologically, as well.
A silver lining for me over the past few months has been the opportunity to summarize results of some research studies including an update from a mulch trial that I'll report on virtually rather than live at the American Society for Horticultural Science conference (that was to be held in Orlando). I thought you might be interested in the results.
The objective of the research project was to measure the impacts of organic mulch treatments on the growth and health of four species of low maintenance, drought-tolerant landscape trees under deficit irrigation. Species selected were Parkinsonia x ‘Desert Museum' (it's thornless!); Chilopsis linearis ‘Bubba' (Desert Willow) (beautiful magenta flowers!), Pistacia ‘Red Push' (hybrid from P. atlantica and P. integerrima with brilliant orange fall foliage), and Prosopis glandulosa ‘Maverick' (thornless). Trees were planted in a randomized complete block experimental design in at the Chino Basin Water Conservation District (CBWCD) in Montclair in October, 2016. Half of the trees received 4” of organic mulch and half did not. Trees were transplanted from 15-gallon containers and irrigated with recycled water at 80 percent of reference evapotranspiration (ETo) the first 12 months.
Irrigation was reduced to 50% ETo in November, 2017 which was maintained until May 2020, when irrigation ceased. While the study continues through October 2020, there are some interesting early results. Organic mulch applications enhanced growth with no loss in quality in the Pistacia, Prosopis glandulosa, and Chilopsis linearis trees while growth was actually better in the Parkinsonia trees that did not receive mulch. This may be due to the fact that its trunk and branches actively photosynthesize as well as its leaves. Parkinsonia leaves also feature sunken guard cells, providing another form of drought avoidance. Furthermore, they develop deep root systems and may not need the added benefit of reduced soil evaporation in the top few inches of soil provided by the mulch. While all of the species selected have wonderful attributes, the Parkinsonia 'Desert Museum' has all the best traits of its palo verde heritage including having no thorns and a continues bloom throughout summer.
A huge thanks to our UCCE San Bernardino County Master Gardener team (led by Irene) who take data quarterly on the trees, recording trunk circumference at 6" and 3'. This is another great example of the breadth and depth of the contributions of our wonderful volunteers!
The four species of landscape trees in this study are part of a larger study at University of California, Riverside to determine the ability of 12 species of landscape trees to mitigate impacts of climate change. While I'll be long retired, growth and health data of all species will continue to be evaluated through at least 2035. The study at CBWCD provided the opportunity for a mulch/no mulch treatment for four of the most promising species which was space-limited at UCR.
Below are plot photos from October 2016 (right after planting), July 2020 (no irrigation for 3 months), a mature 'Desert Museum' tree in prolific bloom (photo credit to Dr. Bob Perry, Emeritus Professor, Cal Poly Pomona), and a mature Chilopsis linearis 'Bubba' from our UCR plot.
Save the date! We will be hosting a virtual UCR Field Day on September 3, 2020 featuring our drought-tolerant landscape plots at UC Riverside that was to be held live last May. More information is forthcoming but it will provide at least four hours of continuing education hours and a chance for you to ask questions of Dr's Amir Haghverdi, Don Merhaut and myself.
Have a wonderful August in your garden!
Sensors, drones, and CIMIS: UCCE Partners with EarthWatch and CBWCD to Save Water in Urban Landscapes
On Friday UCCE San Bernardino County Master Gardener Coordinator Maggie O'Neill and I hosted a tour that showcased UC ANR Urban Water Use Specialist's Amir Haghverdi's landscape plots at the UCR Citrus Experiment Station. In attendance were CEO Scott Kania and Lead Scientist Mark Chandler from EarthWatch, Becky Rittenburg and Monica Curiel from Chino Basin Water Conservation District, and Darrel Jenerette, UC Riverside Professor of Landscape Ecology. Our team is implementing an exciting citizen science project measuring water conservation based on implementing 'best practices' in urban landscapes in the greater Los Angeles Basin.
Amir Haghverdi showing plots to EarthWatch, UCCE and CBWCD teams
EarthWatch, CBWCD, and UCCE San Bernardino team
Drought Update........How to Save Your Plants Under Drought and Water Restrictions......and Use Graywater!
California is in the midst of the worst drought in decades. But you can save your valued trees and landscape plants by following a few simple principles. Watering mature trees deeply just once during mid-summer will keep most species alive, especially if there is a three inch layer of mulch on the top of the soil to keep evaporation down. Be sure to water outward toward the dripline of the tree rather than near the trunk. Keep weeds out of your garden; they will win the water fight. Don't fertilize your landscape during the drought and avoid ripping out your current landscape in the middle of summer to replace it with a drought tolerant one; young plants require more water than established landscapes, and more frequent irrigations. For more information on how to reduce water use in your landscape and garden and to learn more about using graywater from your washing machine to irrigate your landscape click on this link. http://cesanbernardino.ucanr.edu/Drought_Resources/ Janet Hartin, Environmental Horticulture Advisor, University of California ANR Cooperative Extension, San Bernardino, Riverside, and Los Angeles Counties.