Spring let us off easy. Cool daytime temperatures, even a few scattered showers, took the edge off the usual May heat.
That gave us a little breather before the real crunch time begins. Is your garden ready for summer heat – with less water?
Due to California’s epic drought, state-mandated restrictions will severely limit irrigation in many local landscapes. As summer heat escalates into triple-digit territory, visions of brown, parched and dusty yards seem inescapable.
The time to take life-saving action is now. Here’s expert advice on how to help your garden survive this dry summer of 2015:
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Time to re-evaluate
“Look at what grows naturally in the West and take a lesson from that,” suggests Kathleen Norris Brenzel, longtime garden editor at Sunset magazine. “Look at how (plants) grow together in plant communities and try to mimic that. You’ll end up with a garden that will adapt (to drought) without a ton of care. Low-water really is easy care.”
Brenzel recalls the Great Drought of 1976-77.
“Not long after that, I became garden editor of Sunset,” she said. “I was looking for ideas on how we could save water, and I turned to the missions of California. I looked at the gardens put in by the first settlers of California and they were so smart. They used native plants, plants that did well in California naturally.”
Later generations brought their Eastern garden ideas with them, including lush expanses of lawn and greenery, she added.
“Our whole aesthetic changed and so did our whole relationship with water,” Brenzel noted.
Pushed by drought and other concerns, that aesthetic has shifted back to more natural-looking and decidedly less-thirsty landscapes. Focusing on these water-wise alternatives, Brenzel compiled many great drought-busting ideas in her new book, “Sunset Western Garden Book of Easy-Care Plantings: The Ultimate Guide to Low-Water Beds, Borders and Containers” (Sunset, $24.95, 288 pages).
In addition, she’ll also be among the experts offering advice June 6-7 during Sunset’s annual Celebration Weekend at the magazine’s Menlo Park headquarters. Among the hands-on displays and demonstrations will be several devoted to water-wise gardening.
This year, she’s been using a lot of drought-hardy succulents in designs, especially in pots. They add texture and accent color with less water. Group containers so they shade each other; that helps keep them cool and less thirsty.
“Plants in containers tend to use twice as much water as if they were planted in the ground,” Brenzel said. “But succulents are great in containers, and they can look beautiful.”
Starting with her own home, Brenzel has been an advocate for lawn conversion to native or Mediterranean plants that need less water. Hardscape such as tile, gravel or decomposed granite can still give a flat and open look with no water at all. But successful landscape conversions need water, too.
“Should I be planting anything right now? That’s the question we hear over and over,” Brenzel said. “People want to pull out their lawns and plant drought-tolerant plants, but any new landscaping should be held off until fall. Any plant, even drought-tolerant ones, needs water to be established.
“But what you can do now is save what you have. Deep water shrubs and trees; those are your most valuable plants. Then, re-evaluate in the fall.”
Tomatoes and timing
Sacramento’s favorite backyard crop, tomatoes are a must for most local gardeners. But they have a reputation as water hogs. Some studies suggest they need 2 inches of water per week, or twice as much as a lawn.
You can still have a bountiful crop while keeping an eye on irrigation, said Peter Frichette, Sacramento’s Mr. Tomato. He harvests hundreds of tomatoes from very limited space in his Greenhaven backyard.
Grown in sturdy cages, his Better Boy and Early Girl plants already tower 7 feet tall and are loaded with green fruit.
Using drip irrigation, Frichette usually gives each plant 2 gallons of water every third day. With four .6 gallon-per-hour emitters per plant, he irrigates about 45 minutes twice a week or less. He’s been letting his tomatoes tell him they need watering.
“Because of the drought, I have been holding back and waiting until I see the leaves just start to roll (to retain moisture) before I irrigate,” he said. “Due to our cooler weather, I have been watering about every fourth or fifth day.
“Because I am (irrigating) underground, I lose nothing to evaporation, so I am cutting back even more to see just how little these plants can survive with,” he added. “This will vary with the temperature of the day and the size of the vine, as the bigger vine will lose more to transpiration.”
Don’t skimp on young plants that are still rapidly growing vine, he advised. They need water, but make it deep.
“The real key is that the plants really need deep watering in the early growing phases, in order to get the roots foraging down into the earth rather than along the ground,” Frichette said. “There are lots of variables in this endeavor.”
In the rest of the vegetable garden, snake soaker hoses down rows or around mounds and water deeply once a week, Brenzel said. There’s less evaporation and water use than spraying the plants overhead.
Save trees first
“Trees are what I worry about the most in this drought,” Brenzel said. “Give each tree a deep irrigation before we get into the real heat of summer; a good soaking at the dripline (the furthest reach of a tree’s branches and foliage). That way they’ll have good moist soil heading into the summer.”
Mulch around trees to preserve that moisture reserve. Put down a layer of organic mulch (wood chips, bark, shredded leaves, compost, etc.) 4 inches thick in at least a 4-foot circle. Leave a mulch-free circle 6 to 8 inches around the trunk to avoid rot.
Watch out for stress, added Sacramento certified arborist Matt Morgan of Davey Tree Expert Co. “In pine trees, you’ll see needle dieback, loss of needles or browning on the tips. Broadleaf trees, short-term signs are leaf wilt and the tree looks unhappy; it sort of sags. Long-term, there will be burning around the leaves’ edges. They look scorched.”
Coastal redwoods already have fallen victim, he noted. “Once they pass a certain point, they’re gone. There’s no bringing them back.”
Drought weakens a tree’s ability to fight off pests, Morgan said. “Sycamores are showing signs of scale (a sap-sucking pest). Pines are seeing a lot more beetle activity. Borers are attacking birches.”
“Watch your Japanese maples,” Brenzel added. “They can show signs of drought. They’ll need some extra TLC.”
During the summer, water trees deeply and infrequently, about twice a month, Morgan said. Young trees may need more frequent irrigation. “If you stop watering your lawn, remember you still have to water your trees.”
Lance Walheim grows 30 varieties of specialty citrus on his farm near Visalia. “At the end of last season, we had to buy some very expensive water (to keep the trees alive),” he said. “That’s what keeps me up at night. It’s going to be a long, dry summer.”
The longtime master gardener and author also is the go-to home gardening expert for Bayer Advanced, the garden products maker. Drought survival has become his cause.
“Helping citrus in drought comes down to efficient watering,” Walheim said. “Look at your irrigation. Some people water every day – don’t! Or they don’t water thoroughly; they’ll treat their trees like lawn and only give them a sip. Like other trees, water your citrus deeply and infrequently. Make sure to mulch.”
Lack of water will produce smaller fruit, he noted. Watch out for such pests such as scale or aphids. Don’t apply pesticides or fertilizer unless you deep water first. But citrus trees are otherwise fairly resilient.
“In the middle of summer, I deep water every eight to nine days,” he said. “but I make sure the water gets down two to three feet.”
Walheim suggests this trick for deep-watering citrus and other trees: vertical mulching. It’s particularly effective for trees planted in heavy clay soil. Dig or auger holes 12 inches deep or more, spaced every 3 feet around the tree along its dripline, the furthest reach of its branches. Then pack the holes with mulch or compost. Water the holes slowly (a hose set at a low trickle works great), so the mulch becomes moist. That water will then seep into the surrounding ground, helping it stay moist, too.
“Lemons tend to be more vigorous, so they need more water than other citrus,” Walheim added. “For most citrus, irrigating three times a month is plenty. The important thing is to do it properly when you do water.”
Brenzel recommends cutting back even more. She irrigates her citrus once a month or less, sacrificing fruit for water savings.
Deciduous fruit trees such as peaches or plums need twice-monthly irrigation up until harvest. But after that, let them go dry, she said. Irrigate only if the trees wilt.
Roses and ornamentals
Besides his citrus orchard, Walheim grows a lot of roses. He’s the author of “Roses for Dummies” (For Dummies, 2000, 416 pages).
“I’ve put them all on drip irrigation,” he said. “Under normal situations, I give them an inch of water a week in summer. But in this drought, I’ve backed way off. They’re now getting watered once every two weeks or less.”
The key is that his roses are planted in the ground and well established, in place at least a year or more. Their deep roots help them cope. Roses in containers or newly planted will still need weekly irrigation or more.
So far, Walheim’s roses have fared well with less water. “There’s less bloom,” he said. “The plants don’t look as pretty as they usually do. But under this current water situation, it’s OK. Roses are a lot more drought-tolerant than people think.”
Same goes for camellias and azaleas, Brenzel said. “Old camellias and old azaleas are survivors. They’re really drought-tolerant. It doesn’t make sense to pull them out or let them die. Once established, they do really well without much water or attention.”
Roses, ornamental shrubs and perennials all benefit from mulch, Brenzel noted. But like lawn trees, they can be affected when the sprinklers get turned off.
“The key is you’ve got to be aware where they’re getting their water,” she added. “If they’re planted in a border (next to turf), they may have been getting their water from the lawn. Shrubs and perennials may be soaking up that same water. If you stop watering the lawn, you’ll lose them, too.”