Category Archives: drought tolerant plants

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

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, it?s 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, Heart?s Desire, Centennial and Diamond Heights. If deer frequent your landscape you should stick with Anchor Bay, Heart?s Desire and Centennial but the others are great in protected areas.

One of the upright types I grow is ceanothus thysiflorus. It?s 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. It?s 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 don?t 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.

California Natives for Erosion Control

Who knows what the weather will be like this winter but what we do know is that some of our rain events will come with a vengeance. It’s not that unusual for our area to get 8 inches of rainfall during a storm and that can create havoc on an unprotected hillside. Fortunately, October is a good time to do something about it.

Pink Flowering Currant

Fall is the perfect time to plant in our area. The soil is still warm encouraging root growth and the weather is mild. Using the right plants on hillsides can help slow and spread runoff and prevent soil erosion. Mulch also protects soil from direct rain impact and slows runoff across bare soils. Covering the steepest slopes with jute netting through which plants may be installed is an added precaution.

There are many attractive plants that work well for erosion control. Often they need to adapt to shallow, poor soil and cope with less than ideal conditions all while putting down dense, strong roots. California natives are well suited to this job.

Common native shrubs include ceanothus and manzanita of all

Calycanthus occidentalis

types. Calycanthus or Spicebush has fragrant flowers in late spring blooming well into summer with a spicy fragrance. The foliage is aromatic when crushed and changes from a spring green color to pale golden in autumn. Decorative woody fruits last into winter making this shrub attractive year round. It thrives with infrequent to moderate watering. Combine with coffeeberry and deer grass in sunnier spots or with Douglas iris and giant chain fern in shaded spots below trees. All these plants have deep roots and control erosion.

Ribes s. King Edward VII

Ribes sanguinem or Flowering Currant is another show stopper capable of controlling erosion. In the spring the long, flower clusters of this deciduous shrub will dominate your garden. Choose from white flowering ‘White Icicle’ or ?Barrie Coate” and ‘King Edward VII’ with spectacular deep red flower clusters. ‘Spring Showers’ has 8 inch long pink clusters. Grow in full sun to partial shade. This California native requires little water once established and is a valuable nectar source for hummingbirds.

Some other good California native shrubs for erosion control are western redbud, mountain mahogany, western mock orange, lemonade berry, toyon, matilija poppy and western elderberry. ribes viburnifolium, creeping mahonia and baccharis. Ceanothus maritimus, ?Heart?s Desire? and ?Anchor Bay? are all good groundcover selections and are not attractive to deer.

Symphoricarpos – Common Snowberry or Creeping Snowberry – can hold the soil on steep banks. This native tolerates poor soil, lower light and general neglect.

Smaller natives that put down deep roots are yarrow, coast aster, California fuchsia, wild grape, mimulus, buckwheat, wild rose, sage and salvia.

Bush poppy -dendromecon rigid- is another native found right here in our area and needs no irrigation at all once established. Beautiful bright yellow, poppy-like flowers cover the plant in spring. They can be propagated from cuttings taken in summer and are pest and disease free.

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