Tag Archives: drought tolerant plants

Plants that Hold up in the Heat

What happens to a plant when the thermometer tops 100 degrees like it did a couple weeks ago? Planning for more hot weather this summer is a requirement for a successful garden. Are there some plants that can survive tough times more easily?

Bees Bliss salvia

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. But at temperatures about 104 degrees 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 endure hight heat can be stunted, weakened and attract pests and diseases even if water is available.

Plants do have natural systems that respond to heat problems. Some plants are better at this than others. 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 do take resources away from a plants other needs like growth, flowering and fruiting.

It’s no surprise that many California natives are adapted to high temperatures. In my own garden I grow several plants that are doing quite well without irrigation and handled the heat wave just fine. One is Bees Bliss Sage, a low groundcover that can reach 6-8 ft wide draping over rocks and walls. It has an extended bloom time from mid-spring to early fall with whorls of lavender-blue flower spikes. Bees, butterflies and hummingbirds all find it attractive.

salvia clevelandii

Another plant that can handle high temps is salvia clevelandii. Right now it has just started its blooming cycle of electric blue-purple flowers. They will last through the summer. This salvia survives without any supplemental irrigation but if I give it an occasional deep watering and wash off the foliage every so often its much happier.

mimulus arantiacus

Who doesn’t like color in their garden? Mimulus or Sticky Monkey Flower blooms are showy and the hummingbirds love them. The Jelly Bean series has added bright pink colors in addition to white, orange, red and yellow but the traditional aurantiacus types are the most tolerant of drought.

As summer comes along the California fuchsia will provide the color in the garden. I like it that they spread by underground rhizomes and self sow. Free plants are always welcome. I have them planted on a slight slope where they tumble over a rock wall. My bees and hummingbirds find this plant irresistible.

penstemon heterophyllus

Other California native plants that can handle the heat with little water include 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.

These plants can be the rock stars of your garden. Some natives can survive with no water after 2 years many look more attractive with a few deep waterings per summer. And don’t forget the organic soil amendments and wood chip mulch to encourage the soil microbes and keep the soil cool.

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.

The Wonderful World of Aloe

Probably because our winter has been so dramatic every time I see the brilliant flower spikes of an aloe plant glowing brilliant red, yellow and orange I marvel. Beloved by hummingbirds and sustainable garden aficionados alike aloes are easy to grow. So easy that a couple of these tough-as-steel succulents are growing right out of the cracks in a gas station parking lot in town and blooming without any supplemental water or care. How’s that for bullet proof?

Aloe ferox

Our Mediterranean climate is perfectly suited for the exotic looking family of Aloes. Some hail from the Arabian Peninsula and Madagascar but mostly they are native to South Africa. The spikes of their showy flowers supply much needed nectar for hummingbirds at a time that not much else is blooming.

There’s a variety for any space, large or small, container or tree-like. Here are a few of the types I’m seeing blooming right now in our area.

Aloe ferox or Cape Aloe grows best in full sun but tolerates a wide variety of growing conditions. They can thrive in very dry conditions or grow in an area that receives regular irrigation- a good trait given our recent wet winter. The foliage is hardy to at least 20 degrees and the winter flowers down to 24 degrees. Cape aloe grow to 6 feet tall and 3-5 feet wide so plan accordingly if you plant one of these spectacular reddish-orange to orange succulents. Cape Aloe occupies a many habitats in it’s native Cape Region of South Africa and is listed on the endangered plant list.

Aloe arborescens – Torch aloe

Torch Aloe or Aloe arborescens blooms also in fall and winter. The bright yellow or red flower spikes cover this large clumping variety. This species has recently been studied for possible medical uses similar to the well known aloe vera plant. It’s the only other member of the Aloe family that is claimed to be as effective. It can survive much lower winter low temperatures than aloe vera.

Aloe vera has been grown for thousands of years in tropical climates. It is one of the most widely used medicinal plants on the planet. As a houseplant make sure the pot has plenty of drainage holes as they cannot tolerate standing water. Let them go completely dry between waterings and grow them in the very bright light of a south or west facing window.

Aloe maculata

The Soap Aloe or Aloe maculata is so tough that it can survive just about anywhere. Besides the parking lot I mentioned earlier it’s growing in my Bonny Doon garden that receives no winter sun at all. The gritty soil here drains quickly which helps them survive given the 124 inches of rainfall received so far this winter. My Soap Aloe aren’t blooming right now but others in better growing conditions are sporting showy flowers atop tall, multi branched stalks in colors ranging from red to gold. Once established this succulent needs only occasional water to look good. They grow in partial to full sun. The foliage gets 18 to 24 inches tall with the bloom spikes reaching 35 inches tall.

Every garden should have a variety of aloe to feed the hummingbirds in winter.

When Rainfall Causes Problems

If you were waiting for some rain before planting to control erosion wait no more. That last storm brought plenty of the wet stuff and the next round is hopefully not far off. You’ve gotten a reminder of those areas that need stabilization during the rainy season.

Fall is the perfect time to start planning and planting. The nights are cooler, the days shorter and the soil still warm. Everything that a new plant needs to get a good start.

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Steep hillside at author’s house covered with erosion control plantings

Using the right plants on hillsides can help slow, spread runoff and prevent soil erosion. Often they need to adapt to shallow, poor soil and cope with less than ideal conditions all while putting down dense, strong roots. Mulch also protects soil from direct rain impact and slows runoff across bare soils. This is important while new plants are growing in. Covering the steepest slopes with jute netting through which plants may be installed is an added precaution.

What plants are good for controlling erosion in our area? When choosing plants to cover a bank for erosion control, assess the conditions of the area you want to plant. Is it in the sun or shade? Is it a naturally moist area or dry? Do you intend to water it or go with our natural cycle of wet in the winter and dry in the summer? Matching the plant to the site conditions will ensure success. California natives are well suited to this job.

If the area you need to stabilize is large and mostly shade, consider ribes viburnifolium or Evergreen Currant. Like mahonia repens or Creeping Mahonia it needs no irrigation when established. Another native, the Common or Creeping Snowberry can also hold the soil on steep banks, spreading by underground stems that stabilize the soil.

A bank in the sun would contain a different plant palette. Common native shrubs for sun include ceanothus groundcover types such as ‘Centennial’, ‘Anchor Bay’ and maritimus that are not attractive to deer like the larger leaved varieties. Manzanita are also excellent at controlling erosion.

philadelphus_felton_covered_bridge
Western mock orange aka philadelphus lewisii

Some other good California native shrubs for erosion control are Western redbud, mountain mahogany, Western mock orange, lemonade berry, toyon, bush poppy, matilija poppy. spicebush, pink flowering currant and Western elderberry.

Smaller natives that put down deep roots are yarrow, coast aster, California fuchsia, wild grape, mimulus, buckwheat, wild rose, sage, deer and needle grass, Pacific Coast iris, penstemon, artemisia and salvia.

Remember when setting plants on a steep slope to arrange them in staggered

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California fuchsia

rows. Make an individual terrace for each plant and create a basin or low spot behind each one ( not around the stem ) to catch water. Set the crowns of the plants high so they won’t become saturated and rot after watering and make sure mulch does not build up around the stem.

These suggestions are just a few of the plants that control erosion. Every area is different and every situation unique.

Stars of the Fall Garden

More and more of us are embracing the concept of gardening with a sense of place. To garden where you live means accepting that your garden in California is naturally more subdued by fall. Plants that bring color to the garden at this time of year are invaluable. A successful garden is a feeling.

The fall bloomers and ornamental grasses are at their peak right now and thanks to our recent rainfall they are getting a big drink. Many birds are loading up on carbohydrates and fats to provide fuel for their migration. Others will stick around and want to be in the best possible condition for the winter season. In addition to seeds, nuts and acorns, flowers are important in their diets,

leonotis_leonuris
Lion’s Tail

With Halloween almost upon us orange blooming plants like Lion’s Tail look perfect in the autumn garden and gets the attention of birds, bees and butterflies. The scientific name leonotis leonurus translates from the Greek words meaning lion and ear in reference to the resemblance of the flower to a lion’s ear but this perennial shrub has long been called Lion’s Tail in California. A member of the mint family it starts blooming in very early summer and continues through fall. Having very low water needs and hardy down to 20 degrees it’s perfect for a drought tolerant garden.

California fuchsia is also at the height of its blooming season. Starting in the summer and flowering through fall this California native will be covered with orange or scarlet-orange flowers that attract hummingbirds like crazy. A great plant along the path or draping over a rock wall this perennial thrives in areas that might fry other plants. Also known as Epilobium canan or Zauschneria it is in the evening primrose family and native to dry slopes and chaparral especially in California.

bulbine
Orange Stalked Bulbine

Another good choice for your drought tolerant garden is the long blooming Hallmark bulbine. The Orange Stalked bulbine is a succulent you’ve got to try. Starting in late spring and continuing through fall and often into winter this one foot tall groundcover spreads to four or five feet wide. The orange star-like flowers with frilly yellow stamens form atop long stalks that rise above the foliage. Remove spent flower stalks to encourage reblooming.

mimulus
Mimulus Jelly Bean Gold

What’s a fall garden without an orange or gold hued mimulus to feed the hummingbirds? Mine haven’t stopped blooming since early summer. Deer resistant and drought tolerant Sticky Monkey flower get the sticky part of their common name from their leaves which are covered with a resinous oil discouraging the larvae of the checkerspot butterfly from dining too greedily.

Orange and blue are opposite on the color wheel so they look fabulous together. Enter the salvias with their mostly blue and purple flowers. From California natives such as salvia clevelandii to Mexican bush sage to Autumn sage there are thousands of varieties on the market. All are deer resistant, gopher resistant, drought tolerant and hummingbird magnets.

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.