Using mulch on lemon groves reduces need for water, Rancho Santa Fe resident advises
By Joe Tash
A Rancho Santa Fe man is concerned that a combination of drought, skyrocketing water prices and mandatory water-use restrictions could spell the end of the community’s lush, eye-pleasing lemon groves, and he proposes a solution — mulch.
For the past several years, as the cost of water has gone up — rates in San Diego County have doubled over the past decade — people have cut back on watering their groves, causing them to die off and in some cases to be removed entirely, said Bruce Henderson, a resident of Los Mirlitos on the western edge of Rancho Santa Fe.
“The lemon groves add a great deal to the appearance of the place,” said Henderson, who has about 300 lemon trees on his 3.75-acre property. If people don’t adequately water their groves, he said, “the likelihood is these groves will disappear, and we will be left with empty, ugly dirt fields with weeds in them, and property values will suffer as well.”
For the past four years, said Henderson, he has maintained a layer of mulch — ground-up remnants from trees trimmed in the Ranch — which has allowed him to dramatically cut back his water use, while still keeping his trees healthy and green. The mulch acts as an insulating layer, holding moisture in the soil. Henderson said he isn’t trying to produce a stellar lemon crop — he just wants to keep up the appearance of his grove.
Dead and dying lemon trees pose more than an appearance problem; such unhealthy trees are also a fire hazard, said Conor Lenehan, fire prevention specialist and urban forester with the Rancho Santa Fe Fire Protection District.
With the drought and rising water prices, fire district officials have seen an increase of groves in decline as they make their rounds in Rancho Santa Fe, said Lenehan. Some of the groves are on unoccupied or abandoned properties, while in other cases, homeowners have reduced watering, he said.
This leads to twig die-back and defoliation on the trees. When such conditions are evident, Lenehan said, the fire department contacts homeowners and asks them to trim or remove trees to correct the problem. The department also can bring in a contractor to do the work if property owners don’t comply, he said.
Lenehan acknowledged that the loss of lemon trees does affect the community’s rural ambiance. “It is sad to see large parcels have to remove or thin out trees that were once flourishing in Rancho.”
Chuck Badger, owner of RE Badger and Son Inc., which manages farms and groves for property owners, said he shares the concerns about lemon groves dying off from lack of water. He said mulch may be an answer for some property owners, but it depends on the composition of their soil.
The reason he doesn’t routinely recommend mulching, he said, is that in much of Rancho Santa Fe, properties have heavy clay soil, which holds on to water. Mulching directly under citrus trees, he said, can foster the development of
phytopthora, a type of fungus.
“If you don’t let the soil dry out, you’re at risk of that fungus,” he said.
Henderson’s property may have sandier soil that drains more easily, allowing him to mulch and not develop fungus on the roots of his trees, Badger said.
As for water-saving tips, Badger said he advises grove owners to make sure their sprinkler systems are well-maintained so they don’t waste water. “It really is a maintenance issue for most people,” he said.
Badger said it would also be helpful if the Santa Fe Irrigation District, which supplies water to Rancho Santa Fe, Solana Beach and Fairbanks Ranch, offered a discounted agricultural rate to its customers.
The high water rates, he said, have “made people much less likely to take care of their groves,” Badger said.
Creation of an agriculture rate will be considered later this year when the irrigation district conducts a “cost of service study,” in which it looks at its costs and revenue needs for coming years, said Jessica Parks, public information officer with the Santa Fe Irrigation District.
Lemon trees are the No. 1 crop in Rancho Santa Fe, followed by oranges at a distant second, and nursery plants at third, said Badger. Some 400 acres are planted in lemon trees, which are a hardy, drought-resistant crop.
On average, Badger said, an acre of lemon trees needs about an acre-foot of water annually, or about 325,000 gallons. An acre-foot costs about $1,600, he said.
During summer, he said, he waters his groves every other week.
Since he has put down mulch, Henderson said, he has cut back watering his grove to one hour each in July, August and September, for a total of three hours per year, which is enough to maintain his trees.
Residents can get mulch for free by contacting local tree-trimming companies, Henderson said, but they should avoid mulch containing weeds, palm fronds or pine needles.
“You get the mulch for free, then all you have to do is spread it around. My water problem went away just like that,” he said. “There are no weeds, the grove looks good and the trees are happy.”