Category Archives: drought tolerant gardens

Watering Plants in the Summertime

All plants need water– even those that are tolerant of our summer dry conditions. Water makes up 90-98% of every plant we grow. It’s needed for photosynthesis, as well as reproduction and defense against pests.

What happens to a plant when the thermometer tops 100 degrees? Are there some plants that can survive tough times more easily?

Mimulus ‘Jelly Bean Gold’

Photosynthesis is one of the most remarkable biochemical processes on earth and allows plants to use sunlight to make food from water and carbon dioxide. At temperatures about 104 degrees, however, the enzymes that carry out photosynthesis lose their shape and functionality. A garden that provides optimum light and water but gets too hot will be less vigorous. Tomatoes, for example, will drop blossoms and not set fruit if temperatures are over 90 degrees. Plants that do endure hight heat may be stunted and weakened attracting pests and diseases even if water is available.

Plants have natural systems that respond to heat problems. Plants can cool themselves by pumping water out through the leaves for a kind of swamp cooler effect. They can also make ?heat-shock? proteins which reduces problems from over heating. All these strategies can take resources away from a plants other needs like growth, flowering and fruiting.

California fuchsia

It?s no surprise that many California natives are adapted to high temperatures. Some California native plants that can handle the heat with little water include salvia, mimulus, California fuchsia, eriogonum, manzanita, artemisia, California milkweed, ceanothus, mountain mahogany, bush poppy, bush lupine, native penstemon, monardella, mahonia nevinii, fremontodendron and holly-leafed cherry.

Other well adapted plants that are known to be more tolerant of heat include butterfly bush, germander, rosemary, smoke tree, rudbeckia, coreopsis, lantana, plumbago, gaillardia, lilac, sedums, oregano and verbena.

So how much water do different types of plants need during the heat of summer?

Be sure that you water trees and shrubs deeply checking soil moisture first with a trowel. Established small to medium shrubs should be watered when the top 3-6″ is dry, large shrubs and trees when the top 6-12″ is dry.

As a rule of thumb, trees and large shrubs need deep but infrequent irrigation. They should be on a separate valve than your smaller shrubs and perennials. Water ornamental trees 1-3 times per month depending on the type and soil. Tree roots grow 12-36? deep and require 10 gallons of water per inch of trunk diameter.

Bush Poppy

Apply water with a soaker hose, drip system emitters or hand held hose with shut off and soft spray attachment according to your water district?s restrictions. Don?t dig holes in the ground in an effort to water deeply. This dries out roots even more. Be sure to water the root zone to the indicated root depth every time you water. Watering deeper than the root zone only means you are wasting water. You can test how deep you watered by pushing a smooth rod that?s 1/4 inch – 3/8 inch in diameter into the ground soon after you irrigate. The soil probe should easily slide through the wet soil but become difficult to push when reaching dry soil.

The roots of smaller shrubs are 12-24? deep in the soil. Established native shrubs may need only monthly waterings to keep them looking their best while other shrubs may need watering every 7-10 days during the heat of the summer. Perennial roots only go down 12? or so and may need watering once or twice a week depending on type.

With lots of mulch and the above watering tips you can keep all your plants happy and healthy

Interesting Plants to Update your Garden

Tired of seeing the same plants in your garden and everywhere else? Feel like changing things up a bit? With this question in mind I?ve turned to my fellow landscape designers to see what plants they are using these days so that every garden they design doesn?t look the same. You can have too much of a good thing.

One thing I know for sure is that I don?t want to recommend a plant that hasn?t been shown to be a reliable grower in a variety of conditions. Sometimes the latest and greatest plant introduction turns out to be a dud. Other times a new cultivar of an old favorite hits a home run. Here are some oldies but goodies and new plants to add to your garden.

 

Loropetaum ‘Jazz Hands Dwarf PInk’

Loropetalum ?Jazz Hands? is getting the nod from everyone who?s grown it. If you love the deer tolerance, low maintenance. moderate watering and toughness of regular Chinese Fringe Flower this showy dwarf variety is even easier to grow. Staying low and tidy Jazz Hands Dwarf Pink has cool purple foliage with a cranberry undercurrent and hot pink blooms. It looks great combined with Jazz Hands Dwarf White. Local wholesale nurseries are growing it so it?s readily available.

Speaking of local sources for plants, we live in one of the prime growing areas for landscape plants. I recently learned that one of my favorite plants Canyon Snow Pacific coast iris is going through a difficult time. Seems it?s become less vigorous than the other colors in the Canyon series and the growers are working to improve their stock. We need to count on a plant?s performance. There?s enough other issues to deal with in our gardens without starting with a wimpy plant.

Cistus variegata ‘Mickie’

Rockrose have always been favorites in the low water use garden. There?s one with a low, mounding habit that hugs the ground and creates a super colorful accent to the sunny garden. With brilliant gold leaves splashed in the center with green this variegated cistus hybridus called ?Mickie? is hardy in winter, grows only 14-18 inches tall and spreads to about 2 feet wide. Perfect for containers or smaller gardens.

If you like to include California native plants in your garden Woolly Blue Curls or trichostema lanatum has been shown to be reliable in the garden if given full sun, good drainage and little fertilizer or amendment. Group similar plants and forget about them. They bloom from late spring through summer and make a good cut flower. Another common name for this plant is Romero or California Rosemary which dates back to the Portola expedition in 1769.

If you want to make a big splash in your garden or container try growing Salvia ?Amistad? or Friendship Sage. With fast growth in the warm months to 4 or 5 feet tall, the rich royal purple flowers attract hummingbirds and butterflies to the garden. It will grow in light shade with medium water requirements and remain evergreen in warmer parts of your garden.

Cousin Itt acacia

Acacia ?Cousin Itt? continues to be a favorite for many of us. This lovely small plant with emerald green, feathery foliage that stays small in the garden and has low water needs. Not to be confused with the bully acacia tree seen around here, it?s one of the good guys. Plant in full sun to partial shade.

So if you?re in the mood to add a couple of interesting plants to your garden, take a tip from what landscape designers use or grow in their own gardens.

Favorite Plants of Landscape Designers

Big surprise. Many of my friends are also landscape designers. We get together to talk plants, garden design challenges and plant problems while enjoying good food along with a little wine thrown in for good measure. Recently we met in Corralitos to exchange favorite go-to plant ideas and tour the truly fabulous garden of our host. Filled with interesting foliage and texture as well as plants that flower over a long season we all came away excited to use them in our next design. Maybe some of these ideas will work in your own garden.

Fremontodendron californicum

Every interesting garden has good bones. A successful one has a focal point, garden rooms with ?walls? and a ?ceiling?, plants with different textures and foliage color, repetition and unity. My friend?s garden is no exception.

Rivaling for our attention from the breathtaking view of Monterey bay, a fremontodendron, in full bloom, was a real show stopper. This California native shrub requires little irrigation and provided the perfect backdrop to the entry garden.

Loropetalum / Agave ‘Blue Glow’

Other plants that brought this garden to life included a stunning Blue Glow agave paired with the burgundy foliage of loropetalum rubrum. Both have low water needs and aren?t attractive to deer.

Eggs and bacon plant

A small recirculating fountain tucked within a pocket garden provided an inviting lure for songbirds. Surrounded by the unique lotus corniculatus or eggs and bacon plant along with a tropical-looking melianthus major aka honey bush this garden room invited one to stick around for awhile.

We garden designers were impressed with the size and vigor of acacia ?Cousin Itt?. This lovely small plant with emerald green, feathery foliage stays small in the garden and has low water needs. Not to be confused with the bully acacia tree seen around here, it?s one of the good guys. Plant in full sun to partial shade.

Euphorbia wulfennii

In deer country you can?t go wrong with euphorbia characias wulfenii ?Bruce?s Dwarf?. It does an excellent job of seeding itself so beware. Grow it where it can self sow and not become a problem child. Very hardy in winter and water sparingly. In spring and summer the flower heads form at the branch tips covering the plant with a chartreuse color.

A French hybrid lilac called Pocahontas scented the air as we exchanged our favorite plants that pull a garden together. The winners included hardy geraniums like Biokovo and Karmina and California native heuchera maxima. Canyon Snow Pacific coast iris also got a lot of votes. Groundcover sedum ?Angelina? and lime thyme garnered support also.

Abelia ?Kaleidescope? and ?Confetti? got the nod from several of us. Also high on the list of favorite plants, the variegated gold and green cistus was used by many because of its low, mounding habit that hugs the ground and provides a bright evergreen accent to a sunny garden.

So if you?re in the mood to add a couple of interesting plants to your garden, take a tip from what landscape designers use or grow in their own gardens.

Lessons in Water Conservation

There?s a saying that you should learn something new everyday and while visiting Robby Franks? Scotts Valley garden recently I added valuable lessons to my irrigation know-how and successful succulent and other low water-use plant cultivation.

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Slope with dry creek bed, succulents and other low water-use plants.

You might remember a prior column of two about this ?serial mole killer? as Robby laughingly described himself several years ago. He told me he?s licked his huge mole problem by exclusion and trapping plus he?s been the benefactor of a large gopher snake and a couple king snakes from the neighbors so he?s pretty confident now that his garden and all the work that goes into dividing and transplanting and mulching will not go in vain.

The soil in Robby?s garden is quite sandy and thin. He?s done wonders adding his own compost over the years. We all know mulching is one of the best ways to conserve water in the landscape. Robby has long been an advocate of composting and regularly renews the mulch in his garden. He even calls himself “Mr Mulch”. He has permeable paths and a dry river bed that allow rainwater runoff to soak into the soil slowly. He keeps his plants pruned in a naturalistic manner because “smaller plants use less water'”. But all this wasn’t enough. His 3 “dumb timers”, as he calls them, were using too much water. That’s when he started researching weather based smart irrigation timers.

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The dry creek bed

“To me it seemed like an easy way to conserve water and it’s better for the plants as well”, Robby said. “It will increase the irrigation times if the weather is hotter and dryer than usual, decrease it if colder and turn itself off if it rains”. After research Robby eventually chose the Rainbird ?Simple to Set” Smart Indoor/Outdoor Irrigation timer.

At a raised feeding platform a covey of quail were enjoying an afternoon snack. Below a group of Mexican marigold, fortnight lily, society garlic and euphorbia were thriving and Robby explained they are all watered with one irrigation hub called an Apollo 8 Port Bubbler. It is simple to install and screws onto an existing sprinkler riser or other 5/8? tubing. Each port can be adjusted to deliver just the right amount of water to each area. Attached a micro spray to the end of the 1/4? tubing and plants grow larger and deeper root systems.

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Collection of plants requiring little irrigation

Robby?s garden is a diverse collection of plants from all over the world. He told me he?s been impressed how the cordyline are growing and considers them better performers than the popular New Zealand phormium in both heat and cold conditions. But succulents are his passion. He?s got five varieties of sedum, three types of aloe including his favorite ?Red Tip?, two varieties of sempervivum although he laments they are slower growing then he?d like, echeveria and his new favorite plant, Dyckia ?Red Devil?. Although technically not a succulent but in the genus bromeliad it does have similar characteristics. ?They remind me of an underwater scene?, he said. Their dark, spiky foliage did look a bit like giant sea anemone.

Robby does a lot a research and loves to share the knowledge he?s gained about plant cultivation and irrigation. Many a garden in Scotts Valley have benefited from his passion. Robby Frank is on a crusade to save water and Smart Irrigation and mulching is one way to do it.

Sheet Mulch Away that Old Lawn

Replacing that water guzzling lawn or dramatically reducing the size is a good place to start conserving water and is easier than you think. If you?ve been paralyzed with the thought of digging out and hauling away hundreds of square feet of heavy sod or using dangerous grass-killing chemicals, sheet mulching is the method for you.

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Sheet mulching in progress

This simple technique eliminates the lawn by smothering it with layers of compost and renewable materials. Here?s how to do it:

  1. Mow the lawn down to 1-2?, leave the clippings in place and soak with a hose.
  2. Flag the locations of sprinkler heads you will be keeping for your new plantings and cap off the ones you won?t need.
  3. Add an inch of compost to speed up the decay of the grass. If your lawn borders a driveway, path or sidewalk you?ll have to remove about 3? inches deep of soil along these edges and back 8-12? so that the new mulch doesn?t slide off into the sidewalk.
  4. Put down 2-3 layers of newspaper or one layer of cardboard overlapping the edges by 6-8? to prevent regrowth at the edges. You can buy recycled cardboard in rolls for larger projects or find your own at appliance or bicycle stores. Wet the cardboard or newspapers to keep them in place as you go along. It?s best to use cardboard or newspaper thatwill break down quicker. Don?t use plastic sheeting because water and air cannot penetrate it.
  5. Add a 3? layer of mulch such as bark chips from a tree trimming company. You can use compost, straw or shredded plant material. If you have Bermuda grass or other weeds like oxalis you will need to layer about 8? of mulch to smother them.
  6. Water thoroughly.
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Plants installed immediately after sheet mulching

If you can wait a month or more to let the decomposition process get going so much the better. If you just can?t wait you can begin planting now by scraping away the mulch and poking a hole in the cardboard or newspaper where the plant is to go. Then add some compost to help the new plant become established. Be sure to plant high enough to prevent crown rot and keep the mulch a couple inches away from the stem. The top of the root ball should be 1-2? above the soil and just below the mulch.

Modify the sprinkler to drip and remember to adjust your irrigation system run times to accommodate your new plantings.

This is a basic ?lasagna? method for lawn removal. If you are planning to replant with water smart grasses you would choose finer composted mulch instead of bark chips. Either way the process works on the same concept as a compost pile. As the lawn dies from lack of light, it decomposes with the activity of beneficial worms, insects and microorganisms coming up from the soil and doing their job to break down the nitrogen and carbon in the sheet-mulch layers. It?s a win-win situation for the environment and your water bill.

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One year after lawn removal by sheet mulching

Water conservation starts with losing or reducing the thirsty traditional lawn and reducing irrigation. Transform your landscape into a resilient garden that not only saves water but acts to build the earth into a living sponge that harnesses rainwater and replenishes the aquifer at the same time. Attracting wildlife to your new beautiful garden is a bonus.

Be sure to apply for your rebates and have your lawn inspected, even if it?s dead, before you start.

Save Water with a Dry Lush Landscape

In all the years I?ve been a landscape designer I?ve never heard anyone say to me ?I want my garden to look like the desert.?? Using California native plants along with appropriate low water use plants from other Mediterranean dry climate areas can save water and look lush at the same time. We live in an area naturally rich with trees and shrubs and wildflowers that survive on seasonal rainfall. Here are some ideas to give your landscape a lush look while saving water.

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Succulent garden in progress

There?s no better place that showcases a dry lush landscape that my friend Richard Hencke?s garden in Scotts Valley.? Doc Hencke has been at this gardening business a long time starting when he was a kid in Texas and Oklahoma. I am always inspired whenever I visit his garden and come home with a car full of plant starts from his greenhouse. He?s a propagator extraordinaire who loves to share and is a good friend.

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Judy’s succulent garden

On this day I also wanted to see his new raccoon-proof pond and surrounding landscaping. There calandrina starts are settling in nicely. They haven?t started blooming yet but will soon with those neon-pink flowers that sway above the plant on long stems. This spectacular Chilean perennial is long blooming and perfect for a dry garden or difficult spot like a parking strip or hillside. It will suppress weeds as it grows, quickly spreading into a dense groundcover. Nearby is another bed filled with aeonium, sedums, kalanchoe, baby toes and other succulents designed by his wife, Judy.

Doc Hencke?s garden is comprised of a couple dozen different areas or garden rooms. He?s been enjoying discovering new succulents and adding to the new dry lush hillside. He?s growing several varieties of aloe, cordyline and yucca along with douglas iris which are doing fine given the same irrigation as the rest of the dry hillside. Blue Chalksticks or senecio mandralis border the path and their long bluish-green fleshy leaves look great near the red cordyline.

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Doc Hencke’s dry lush entry landscaping

The secret to a lush look is to group plants into a vignette of complimentary elements. A vignette is a brief but powerful scene. Garden vignettes can be more than just plants. Doc Hencke?s driveway garden is a good example. An array of textural plants is combined with a weathered teak bench, richly colored, glazed pots filled with the architectural strappy leaves of phormium and a recirculating water fountain to complete the scene. The blue stone retaining wall is the perfect compliment to the blue and gold succulents that grow in the nooks and crannies.

A dry lush plant palette could also include plants such as Little John bottlebrush, dietes ?Katrina?, Festival Burgundy cordyline, Hot Lips salvia, Variegated dianella, Amazing Red phormium, Icee Blue podocarpus, phlomis, Southern Moon rhaphiolepis, Gulf Stream nandina and Cousin Itt acacia.

A visit to this amazing garden wouldn?t be complete without admiring Doc Hencke?s prized Sand plum which he swears is the tallest in the country. Also called Chickasaw plums they are found naturally on sandy prairies in Oklahoma and Texas where they are very effective in stopping blowing sand. Wikepedia states this early blooming plum grows to 20 feet tall and Richard?s is about 30 feet tall. Just another in his long line of horticultural successes.