Tag Archives: drought tolerant plants

Helping your Garden Survive the Heat

Matilija poppies are known as Fried Egg plant. Be careful the sap of this plant
is poisonous to humans and animals.

Looks like we’re in for a hot summer. Already we’ve had scorching temperatures and since it’s only the beginning of July, you can bet there will be more hot spells. How can you help your plants survive a heat wave? Are there some plants better adapted to handle hot temperatures?

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 high heat can be stunted, weakened and attract pests and diseases even if water is available.

Understanding how plants respond to heat stress is important for developing crops that can withstand rising temperatures and more frequent heat waves under climate change. Much research is being done to counter drastically reduced crop harvests from increased temperatures.

California Fuchsia has adapted to heat and drought.

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 take resources away from a plants other needs like growth, flowering and fruiting.

Plants respond to heat stress by activating hormones which act as chemical messengers. Brassinosteroids are one of these hormones. They have growth promoting properties as well as the ability to increase the heat stress resistance of plants. Because it is a natural product it is approved for organic farming. Research continues to create varieties that are more resistance to heat stress and also provide more stable harvests.

It’s no surprise that many California natives are adapted to high temperatures. Bees Bliss Sage, a low groundcover that can reach 6-8 ft wide is a plant that can 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.

Another plant that can handle high temps is salvia clevelandii. Their blooming cycle of electric blue-purple flowers will last through the summer. This salvia survives without any supplemental irrigation but if you give it an occasional deep watering and wash off the foliage every so often it’s much happier. All the salvias are good performers in the heat. Just be sure to keep them groomed of dead leaves and branches to keep your garden fire safe.

Jelly Bean Gold Mimulus

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.

Other California native plants that can handle the heat with little water include matilija poppy, eriogonum, manzanita, artemisia, California milkweed, California fuchsia, ceanothus, mountain mahogany, bush poppy, bush lupine, native penstemon, monardella, mahonia nevinii , fremontodendron and holly-leafed cherry.

Non-native but 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 that are able to survive with no irrigation after 2 years may look more attractive with a few deep waterings per summer. And don’t forget the wood chip mulch (not bark chips) to encourage the soil microbes and keep the soil cool.

These are a Few of my Favorite Plants

While staying at a friends house during the evacuation I was able to stroll through her garden. Shes also a landscape designer and her garden is as beautiful as youd imagine. Shes addicted to plants and keeps adding to her megs collection on a regular basis. Among the blooming perennials I came across were some of my person favorites. All three are wonderful low water, wildlife and pollinator friendly plants.

Epilobium ‘Everett’s Choice’

The first plant that caught my eye was an epilobium Everetts Choice. The name Epilobium is considered current but this group of sub-shrubs used to be called Zauschneria and are so different from the other epilobiums like Fireweed that many California native plant enthusiasts and even the experts often still refer to them as Zauschneria.

This low-growing vigorous ground-hugging shrub remains under 6 inches tall by up to 4 to 5 feet wide with fuzzy gray-green leaves that are covered with long whitish hairs. Vivid red-orange tubular flowers are produced in profusion in the late summer into fall. It does best in full sun but will tolerate some shade. Quite drought tolerant, but remains a fuller and more attractive plant with an occasional summer watering. It likes well-drained soil best but will do OK in heavier soils if not over watered. California fuchsia are deer resistant and attractive to hummingbirds.

Echo Mango kniphofia

The second plant that caught my eye is also a hummingbird magnet. Kniphofia, also called Red Hot Poker blooms spring into summer with torch-like clusters that open from the bottom up. The selection at my friends garden was probably Echo Mango. Whether the cultivar blooms with red, yellow, orange or mango colored flowers this perennial grows to about 3 feet tall and 4 feet wide in full sun. It is evergreen and requires little summer water. Deer dont like this plant either so thats a plus and its hardy to below 15 degrees.

Sdum ‘Autumn Joy’

Many of you already grow sedum spectabile Autumn Joy. A succulent perennial to 1-2 feet tall it has wide cabbage-like rosettes of pale blue-green leaves and rich, dark pink flowers that put on a spectacular show above foliage in summer and fall. Plant in sun in a dry well-drained soil and water however much or little you want. The foliage dies back in the winter but is root hardy to below -30 degrees. This group of sedum was given the prestigious Royal Horticultural Societys Award of Garden Merit in 1993. Beautiful in the rock garden, perennial garden or spotted into a natural meadow setting it attracts bees and butterflies and is deer resistant. The seed heads can be left for winter interest as well as a food source for birds but stems should be removed prior to the new buds opening in February.

Any one of these plants would be a lovely addition to your garden if you dont already grow them.

Knee High by the Fourth of July

A black-tailed deer celebrating the Fourth of July.

Who doesnt love corn on the cob fresh either from the garden or farmers market? But this column isnt about growing corn or about patriotic deer, its about climate smart plants that hold up to the heat. So lets get started.

All this talk about drought tolerant plants or water smart plants is misleading in some ways. What really matters for the success of a plant in your garden is that they are climate smart. You can call the new California garden climate tolerant or climate adapted but it all comes down to the same thing. The plants you choose to grow in your garden should be able to naturally tolerate periods of lower than average water. This doesnt mean no water during extremely long dry periods. No plant can live without water.

I have two books that I look to for plant ideas when called upon to design a garden in our area. This first was published by East Bay MUD in 2004 and is called Plants and Landscapes for Summer-Dry Climates. The other book I refer to regularly for ideas and information is California Native Plants for the Garden. Both are invaluable in these times of water conservation. One of the best tips each of them offer is to garden where you live.

All of us live in a summer-dry climate. Summer-dry gardens are naturally dry for long periods. Knowing which type of plant community you live in can make the difference between success and failure in your garden. Choose the right plant for the right place whether its a California native from an area with similar soil and exposure or a plant from another Mediterranean-like climate with growing conditions like yours.

Plant communities have evolved over time with geologic changes in climate, topography and soils. We have several district areas here- mixed evergreen forest, redwood forest, chaparral and sandhills.

If you live in a mixed evergreen forest you garden with trees like coast live oak, tan oak, madrone, bay and buckeye. Understory plants include ceanothus, coffeeberry, hazel and poison oak. Your soil contains serpentine and granite. Many other unthirsty plants like salvias, lavender, santolina, society garlic, giant feather grass, rosemary and rockrose do well here. California natives such as western mock orange (philadelphus lewisii), wild ginger and western sword ferns grow here also.

Mixed evergreen forest may also be found along canyon bottoms near streams where big leaf maple, white alder, cottonwood, and western sycamore trees grow. Most plant here grow lush in this deep soil. If you are looking to add something new to your garden here consider giant chain fern, aquilegia, dicentra, Pacific Coast iris and fuchsia-flowering gooseberry.

Found in the sandhills, silverleaf manzanita is perfectly suited to its environment.

Chaparral areas are the hottest, driest slopes of these mountains. Dense thickets of manzanita, coyote brush, chamise, coffeeberry, ceanothus, monkey flower and sage are native here. These plants are adapted to little water and often have tiny, thick, waxy, light green or grayish leaves. Soils tend to be rocky and shallow with overlaying rock or a subsoil that is mostly clay. Plants here need to have an extensive root system that reaches widely and deeply for water. If you live here a classic combination would be the spring blooming western redbud and Julia Phelps or Dark Star ceanothus. The combination of magenta and electric blue flowers is unforgettable.

The sandhills near Quail Hollow and Bonny Doon around Martin Rd. are part of an ancient sandy sea floor that was uplifted, eroded and exposed. These sandy soils lack organic matter and nutrients and their white color magnifies the temperature of the summer sun. Unique, native plants like silverleaf manzanita and Ben Lomond wallflower live here. Buckwheat and sticky monkey flower do well here. You might also try growing Lewisia, a pretty little plant native to northern California, thrives in sand and gravel soils with good drainage. This 8″ tall hardy perennial blooms from spring to early summer with extremely showy flower clusters in colors ranging from apricot to pink, rose and bright cherry red. Mulch them with gravel or crushed stone.

Remember right plant-right place. Dont try to force nature although most gardens do look better with some summer water. Closer to the house we expect a fuller look. Combinations Im going to try this season include leucospermum paired with blue echium or grey-leafed westringia planted with red-flowering callistemon Little John.

Autumnal Equinox

The autumnal equinox will arrive on Monday, September 23rd this year. It’s the official start of fall when the sun crosses the celestial equator and moves southward. The earth’s axis of rotation is perpendicular to the line connecting the centers of the earth and the sun on this day. Many people believe that the earth experiences 12 hours each of day and night on the equinox. However, this is not exactly the case.

During the equinox, the length is nearly equal but not entirely because the day is slightly longer in places that are further away from the equator – like where we live. Also the sun takes longer to rise and set in these locations as it does not set straight down but in a horizontal direction.

With the changing of the season, take advantage of fall planting weather. It was a hot summer and Im ready for fall. This is the perfect time for transplanting or adding new plants to your garden. Why? Cooler air is kinder to plant foliage while soil temperatures are still warm creating an excellent environment for new root growth. In the fall many plants and trees, even broadleaf evergreens, are entering a period of dormancy. With no need to allocate resources into foliage, plants are transferring all their energy into roots and storing nutrients for the cool months ahead. By spring, the new root systems should be well established.

I had hoped to spend some time at the UCSC Arboretum earlier this year when the showy pincushion and leucospermum protea were flowering but I never made it. Because anytimes a good time to visit the arboretum I dropped by recently. There is always something in bloom there and the hummingbirds know it. Here are just a few of the spectacular fall blooming plants that you might want to add to your own garden.

Leaucadendron Jester

The Leaucadendron Jester (Sunshine Conebush), another type of protea, were loaded with brilliant deep wine-red bracts. This evergreen shrub grows to 5 feet tall and is very pest and disease resistant. Deer arent interested in the showy bright pink, cream and green foliage and its quite drought tolerant once established. You can cut the branches as they are prized for use in floral arrangement. People think that protea are hard to grow but really its a plant-it-and almost-forget-it kind of plant. They need good drainage and dont like phosphorus fertilizer preferring poor soils with minimal care. Sounds like a winner to me.

Epilobium ‘Mattole Select’

A little further down the trail I came across another easy to care for plant. California fuchsia have undergone several name changes over the years but whether you call them epilobium or zauchneria they are in bloom now. The ‘Mattole Select’ cultivar forms tidy 6 inch high mats of beautiful silver foliage. Late summer through fall brings orangey-red tubular flowers which attract hummingbirds. Spreading by underground rhizomes, this epilobium increases size a little less vigorously than the others. Its more shade tolerant than most California fuchsias and needs just a bit more water but its still quite drought tolerant. Pruning plants down to a few inches in late autumn helps rejuvenate them for the following year.

Grevillea junipera ‘Monoglo’

As I followed the hummingbirds around the arboretum I came across another groundcover that both the birds and the bees favored. Grevillea juniperina Molonglo (Juniper Leafed Grevillea) blooms with a soft yellow flower unlike most grevillea. This fast growing evergreen forms a mass of dark green soft needle-like leaves and bears an extremely profuse show of light golden yellow flowers from late spring to winter. This tough hardy drought tolerant plants is the perfect groundcover for large areas and will cascade down slopes and walls.

Im looking forward to another visit to the arboretum this winter as the Australian garden will be in full bloom then.

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

Its 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 districts restrictions. Dont 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 thats 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

Ceanothus: The Most Valuable Plant in your Garden

Those of you who read my column regularly might have noticed I often write about plants that are valuable to the birds and the bees as well as butterflies and wildlife in the general. I have 10 bird feeders around my house. Four for the hummingbirds and the other six have black oil sunflower seed and hulled chips. At this time of year when there are so many young the extra food is much appreciated. I provide water and nectar plants for the bees and butterflies as well. If I had to choose one plant to grow that would provide the most benefit for all the critters it would be ceanothus. Hands down, its the best and here are some of my favorite varieties.

Ceanothus ‘Carmel Creeper’

Ceanothus ‘Heart’s Desire’

The groundcover varieties I have in my landscape are Anchor Bay, Carmel Creeper, Hearts Desire, Centennial and Diamond Heights. If deer frequent your landscape you should stick with Anchor Bay, Hearts Desire and Centennial but the others are great in protected areas.

One of the upright types I grow is ceanothus thysiflorus. Its one of the earliest native shrubs to bloom in our area. Ceanothus thyrsiflorus grow along a narrow band close to the coast from Monterey to southern Oregon. I also grow Julia Phelps with those electric blue flowers and Ray Hartman.

A new variety I’ve recently learned about from my friend and fellow Press Banner columnist, Colly Gruczelak, is called Celestial Blue. She planted several 2 years ago from 4″ mail order sleeves and they are now 3 ft tall and 4 ft wide. In her sandy garden, home to her personal deer population, the flowers look like blueberry sherbet. With a light fragrance, described as grape tart, it makes a good screen or accent. This cultivar is probably a hybrid of Julia Phelps and Concha. A horticultural cultivar is simply a plant variety that’s been selected specifically for gardens. Celestial Blue flowers 9 months a year especially in the summer when it explodes with rich purplish blue flowers.

A great variety I often use when designing a garden is Ceanothus Concha because it will accept summer water more forgivingly than most and tolerates clay soil more than other species.

Joyce Coulter ceanothus also tolerates clay, summer irrigation and shearing better than other cultivars. Its a good bloomer, drought tolerant and is covered in spring with wildly fragrant blue three-inch flower spikes.

Ceanothus is often said to be short lived. Most varieties need good drainage, little summer water and dont need soil amendments. In their wild conditions ceanothus plants have a natural life cycle of 10-15 years although some live longer.

Diamond Heights ceanothus

Several members of the ceanothus family can form a symbiotic relationship with soil micro-organisms and fungi, forming root nodules which fix nitrogen. This is a reason why fertilizing is not normally recommended. Adding fertilizer mights kill off the good micro-organisms. Ceanothus are better left fending for themselves.

Ceanothus provide excellent habitat for birds and insects. They are good for attracting bee and fly pollinators and are the larval host plants for the beautiful ceanothus silkmoth. Ceanothus seed is readily eaten by many local birds. Planting a ceanothus is an important step to attracting more birds and wildlife to your garden.

Early California Indians used the fresh or dried flowers of some varieties for washing, lathered into a soap. it has been said to relieve poison oak, eczema and rash.