Category 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.

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.

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.

robby_frank_slope_sept2016_
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.

robby_frank_garden1
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.

robby_frank_garden2
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.

Succulents: One Solution for the New California Garden

According to Weather West, a California weather blog authored by climate scientist, Daniel Swain, the latest seasonal predictions do not inspire a great deal of hope that the coming winter will bring drought relief. “A substantial La Nina event no longer appears to be in the cards. If it’s present at all, it will probably be quite weak.” Seems that persistent West Coast winter ridge may just rear its ugly head again. Even if subtle shifts in the large-scale atmosphere pattern lead to a different outcome here, our persistent drought is still on the table.

aeonium_sunburst_statice
Aeonium ‘Sunburst’ with statice limonium perezii

More and more people are asking me to update their landscaping to use less water and be lower maintenance. Many want a more modern look and what could be more architectural and clean looking than a succulent garden?

Converting to a low water landscape requires careful planning and design to achieve the look you want. You need to evaluate drainage patterns, soil types, slopes, areas of sun and shade and building locations. Hardscape features, such as patios, paths and decks require no water to maintain and by selecting permeable materials such as porous pavers and gravel, rainwater can infiltrate the ground. Large boulders can be used as accents.

Next comes the fun part- plant selection. In choosing the best succulents for your garden think about if your area gets frost during the winter. Does it have protection from a building or evergreen tree or do you live in a banana belt that rarely freezes? Are you planting in sun, shade or a combination?

In addition to the hardy succulents like sedum and sempervivum many showy succulents need only a bit of protection during our winters. Aeonium decorum ‘Sunburst’ is one of the showiest species with spectacular variegated cream and green 10″ rosettes. It looks terrific planted with black Voodoo aeonium. Aeoniums do well in our climate as they come from Arabia, East Africa and the Canary Islands where winter rainfall is the norm.

echeveria_lace-closeup
Echeveria ‘Lace’

Echeveria grow naturally in higher elevations of central Mexico to northwestern South America and so also do well in our our cool wet winters. ‘After Glow’ is frost tolerant and looks to be painted with florescent paint. There are spectacular hybrids being developed every year. These are not as hardy as the traditional hens and chicks but well worth the effort to find a place where they can survive a freeze. Frilly ‘Mauna Loa’ sports turquoise and burgundy foliage while Blue Curls echeveria looks like an anemone in a tide pool.

OLYMPUS DIGITAL CAMERA
Succulent selections

Aloes from South Africa and Arabia are old world plants. Many, like the medicinal aloe vera, are frost tender, but other such as the tree-like aloe plicitilis are hardy down to 25 degrees and look great either in the garden or in pots. Did you know the Egyptians used aloe in the mummification process or that there are no known wild populations of aloe? In South Africa an aloe called ferox is used in the same way as aloe vera for burns and stomach problems.

To ensure success when growing succulents, make sure your soil is fast draining. Our winter rains can rot even the toughest plants when their feet sit in soggy soil. Add sand, gravel or pumice to your soil or plant on mounds to increase drainage.

A Walk on the Wildside: The Ongoing Saga of the Hillbilly Gardener

rose_Fourth_of_July
Fourth of July roses

Many years ago I was invited by a Scotts Valley resident to visit their garden. This was no ordinary garden I was to learn during my visit and each spring I look forward to seeing what’s new at Doc Hencke’s garden. From his roots in Oklahoma and Texas he describes himself as the “Hillbilly Gardener” but with his extensive knowledge of trees, vines and just about anything that grows he is one of the most successful and enthusiastic horticulturists I know. I wore my walking shoes and we started talking about what changes he’s noted in his landscape the past few years of drought coupled with this winter’s rains.

straw_bale_veggie_garden_Ghio_bearded_iris
Straw bale veggie garden with Joe Ghio bearded iris

First stop- the straw bale veggie garden. The soil in this part of the garden is blue hard sub soil so this above-ground method of cultivation has been a real success. Richard told me that when the bales were first put in place a couple years ago he watered them thoroughly to start the fermentation process. Using a meat thermometer he determined by the internal temperature when fermentation was complete. He then soaked the bales with liquid organic fertilizer and applied some blood meal to augment nitrogen. The straw bales are decomposing each year but he’s going to use them once more this season. His crop of kale, lettuces and chard looked robust and happy.

Nearby a bed of Joe Ghio hybrid bearded iris were in full bloom. “It’s been a great year for iris”, Richard said. Not so good for peach leaf curl. The rains this winter set the perfect stage for the fungus to proliferate. He joked that the birds get the peaches anyway.

Richard is redoing his pond this year. He’s tired of fighting the raccoons and algae. Steeper sides will deter the raccoons and deeper water will help to prevent algae growth. He was forced to remove a curly willow that shed leaves into the pond as their natural salicylic acid was poisoning the pond.

succulent_collection
Succulent collection with blooming kangaroo paw

Last year a new succulent bed was planted along the back of the house and patio. His Sticks on Fire all died over the winter from the cold and rain but the aeonium ’Zwartkop’, echeveria ’Sunburst’, kangaroo paw and various sedums were filling in nicely.

weeping_leptospermum
Weeping leptospermun

Below the patio the golden Mexican marigold and blue Pride of Madeira were in full bloom along with a gorgeous stand of Weeping Leptospermum. “Magnificent this year, just look at this plant. Can you imagine what it’s going to look like in another 15 years?”, he said. Pointing out the visual boundaries he creates with flowering vines growing up into the trees, Richard observed that some are going better than others. Sound familiar in your own garden? Even this expert propagator is sometimes stymied by Mother Nature.

Richard_and_the_giant_ China_Doll
Richard and his giant China Doll tree

I love to hear Doc Hencke’s stories as he shows me around. Stopping at a China Doll houseplant that has now grown into a tree he tells me he thinks it’s one of the tallest specimens ever. His giant bird of paradise flower pod opened last week. I’d never seen their enormous blue, prehistoric-looking flowers before.

Richard’s new desert garden along the driveway is growing in nicely with the aloe plicatilis blooming for the first time. Also the yucca he and his brother dug up inTexas is finally blooming. “I’ve only waited 52 years for it”, he laughs.

There are so many stories that come with each and every plant in Richard’s collection. It’s always a walk on the wild side.