Monthly Archives: July 2022

Design trends

Poisonous Plants in the Garden

Hydrangeas contain cyanide

When you look at the list of plants that are toxic in one way or another to humans or pets, it’s a wonder any of us has survived. Maybe it goes under the same category as drinking out of a garden hose when you were young but poisonous plants are a more serious threat. Take a look at your garden and evaluate the risks of these common plants if you have pets or small children.

Not that long ago I was suggesting vines for a design I was working on. The client had a dog that nibbled plants so I wanted to make sure none were toxic. Of the common vines I suggested that do well in our area Bower Vine, Royal Trumpet Vine, Goldflame Honeysuckle and Lavender Trumpet Vine were eliminated from our consideration.

Many of us are including native plants in our landscapes to attract wildlife and save water and resources. Here are some common native plants that you should be aware of if you have small children. This list comes from
Borstein, Foss and O’Brian- California Native plants for the Garden.

Coffeeberry- leaves, berries and bark
California buckeye- all parts (poisonous to bees also)
Western azalea- all parts
Elderberry- all parts except ripe berries and fruit
Solanum-all parts
Snowberry-berries
California buttercup- juice of the plant
Berberis- roots and leaves
Prunus ( cherry )- seeds
California poppy- all parts
Lupine (annual)- seeds, fresh leaves and stems.

Beware the lovely rhododendron

Rhododendrons are just one or our beautiful plants that are poisonous. Children are more susceptible to the effects of plant toxins and should be taught not to eat seeds, berries or leaves from any plant. Do not assume a plant is nontoxic because birds or wildlife can consume it without harmful effects. Be prepared for an emergency by keeping syrup of ipecac on hand and the number of the Poison Control Center. ( 1-800-222-1222 )

Small pets can also be at risk if they ingest parts of poisonous plants out in the yard. Know what plants you have and keep a list. Oleander and foxglove are notorious deadly plants. Here are just some others you might not know.

Hydrangea leaves, flowers and branches contain cyanide. Lantana foliage and especially unripe berries also contain dangerous toxins while delphinium leaves and seeds contain toxic alkaloids which decrease as the plant ages. Sweet peas, lobelia, impatiens, carnations, calla lily, mums and bleeding hearts also have plant parts with come degree of negative effect if ingested.

Surprisingly, even some vegetables contain natural toxins. Diseased celery and green potatoes as well as potato leaves and sprouts produce a very strong toxin. Raw, green, young asparagus shoots can cause dermatitis and the red berries that form on their feathery branches are poisonous. Large quantities of tomato leaves and stems contain alkaloid poisons. Livestock have died from eating the foliage. I guess the deer that browse your tomato vines aren’t ingesting enough to cause them harm as they seem to know just when you have another set of buds for them to nibble.

Trees are not the most common cause of accidental poisonings around the home but a few species may present a hazard.

The black seed inside apples contain cyanide although you have to eat large quantities for them to be deadly. Peach kernals, bark and twigs contain cyanide also as do apricot, cherry and plum pits.

You don’t have to eliminate plants around the home that have natural toxins. Humans have lived for centuries around gardens and orchards. Just be prepared by knowing what plants grow on your property.

Design trends

Planting Tips for Containers

Native Western Azalea is a sure “thriller” in any container

I used to have over 300 containers. Then I whittled them down to 200. The fire took care of that but I saved a bunch by cutting away burned roots, replacing melted pots and giving the survivors some TLC. I consider them pets now given all the care I have given them over the past two years. Now that they are showing progress I have my eye on planting new containers with natives, succulents and more flowers for the butterflies. I might try my hand at container vegetables again although last year’s effort was not very successful given the amount of shade that I have. Every gardener has their your own trial and tribulations, too, so I’ll quit whining now.

Adding California natives to my collection of container plants has been a goal for a long time. Besides attracting birds and wildlife to the garden they use less water than most container plants plus they are beautiful. Gardening in containers is easy. You can control the soil, water and light and the gophers can’t undermine your efforts. There are a lot of California native plants that do well in containers and I’m going to place them where both the birds and I can enjoy them.

This Woodwardia is growing in the ground but they also do great in containers

Natives that will do well in part shade include Western Azalea (Rhododendron occidentale), Chaparral Pea, Giant Chain Fern (woodwardia) and Deer grass. These plants grow big and are best for large containers. You can visit CalScape website for more native plants for any exposure and tailored to your exact location. https://calscape.org/search/

Dramatic containers utilize the concept of combining a thriller, some fillers and spiller or two. Not all my containers will use this formula but I seem to be drawn to those that do. Plants in nature can be quite random in the way they grow together and still be lovely. Containers need a bit more order to dazzle and direct the eye.

Thrillers act as the centerpiece of a container. They are usually big, bold and beautiful. Giant Elk Clover is one such California native that is an attention getter. It grows in part shade. Others that need more sun include Chilopsis linearis (Desert Willow) is another great subject for containers as it is slow growing and beautiful in leaf and flower. Other architectural natives that will catch your eye as the centerpiece of a container are Hardy Hibiscus (Rose Mallow) and Pacific Dogwood. The thriller goes in the center of the pot or if your container will be viewed from only one side it goes in the back.

Next come the fillers. They can be foliage or flowering plants but they should complement and not overwhelm your largest plant. Usually they have a mounding shape and I’ll plant several around the thriller. Good fillers include Heuchera maxima and Western Maidenhair fern, both which like part shade. Lucky for me.

The last plants I’ll add are the spillers which are small and will soften the edge of the container. Redwood Sorrel, Wild Ginger and Miner’s Lettuce are good choices. California Fuchsia would look spectacular with its red or orange flowers and grey foliage spilling down the side of my container if I had more sun.

In choosing a container, remember a porous clay pot will dry out fast in the summer sun as will a small pot. If you want pots on a sunny deck, you’ll have better results if your container is made or ceramic or colored plastic and is big enough to allow 2 inches of potting soil around the root ball. I don’t use water absorbing polymer granules in my containers as they are all in shade in winter and would stay too wet depriving plant roots of oxygen.

Water when the top inch or two of soil is dry depending on the size of the container.. On a very hot day, watering mid-day will cool the soil although I like to get my watering done early. Get to know your plants. Plants that are still growing into their containers need less frequent watering than those that are getting root bound. How much water? Water until it runs out the bottom and empty the saucer the next day if any water remains. Use a gentle nozzle that doesn’t dislodge the soil or compact it. Also make sure the water in the hose isn’t hot from lying in the sun.

The best overall soil mix for natives in containers is sharp sand and horticultural pumice added to a good potting soil. Never use perlite or that puffed up pumice because it will float and look terrible Don’t add gravel or clay shards at the bottom of the pot as this impedes drainage. It work best to fill the entire pot with soil, top to bottom with a screen over the hole to keep out earwigs and sowbugs.

Design trends

Creating a Cutting Garden

With a cutting garden you, too, can put together bouquets like they do at Filoli Gardens.

Until about 100 years ago, one of the most important areas of any large garden was the cutting garden where flowers were harvested like a crop and taken inside for display. Today our lifestyles and tastes are reflected in bouquets that are more casual. The bouquets you make from garden grown flowers, interesting foliage branches, grasses, vines and even herbs always seem to have more personality and cottage garden softness than ones bought from the store. So if you picture yourself strolling out in your garden, bucket in hand to cut beautiful richly colored, fragrant bouquets for your own home or to give to family or friends here are some tips that will make that happen.

Flowers that lend themselves to cutting with long stems and a long vase life can be incorporated into any spot of the garden but if you enjoy lots of cut flowers indoors you may want to set aside a small bed primarily for an old-fashioned cutting garden. A seldom used side yard would be an ideal place as long as it receives at least a half day of sun. Or how about that narrow bed along the fence you never know what to do with? if you’ve never planted in the soil of your future cutting garden, amend the soil generously with organic matter or compost. Then water to germinate weed seeds and hoe them off. Don’t turn the soil again as you’ll bring up more weed seeds. Now you’re ready to plant.

Perennial flowers are prized as cut flowers. Many annuals are good as well as grasses or the strap-like leaves of flax or cordyline. Prunings from the smoke tree, oakleaf hydrangea, grapes and Japanese maple look handsome in bouquets, too.

What can you still plant this time of year for cutting? Marigolds, cosmos and zinnias are annuals that are quick to germinate and easy to grow. Snapdragons are great cut flowers also. A tip for zinnias to make them last longer is to pick the flowers then they open but before pollen shows otherwise they don’t open well. Both hummingbirds and butterflies like zinnias.

Perennial flowers are among the most prized of all cut flowers. Coral bells, scabiosa, gerbera daisy, mimulus, hosta, aster, yarrow and shasta daisy can be planted now, too. Delphinium, kangaroo paw, alstroemeria, penstemon, copeopsis, dahlia, gloriosa daisy and coneflowers are just a few more of the stars of a cutting garden.

Native flowers that last for a week or more include clarkia and sticky monkeyflower. Yarrow and hummingbird sage will last 4-6 days.

While just about any plant material that strikes your fancy will work in a mixed bouquet there are four types of plant forms that naturally look good together: Spires for height and architectural properties with flowers like liatris, snapdragon, gladiola, salvia, Bells-of-Ireland as well as the strappy leaves of flax or cordyline. Round flowers such as roses, dahlias, long-stemmed marigolds and peonies provide focus. Lacy flowers are fillers- ferns, baby’s breath, dill. Foliage from shrubs such as abelia, breath of heaven, California. bay, ornamental grasses, grapes and other vines, herbs, woody tree branches like smoke tree and Japanese maple which also look handsome in a bouquet.

A deconstructed arrangement separates each type of flower into their own vase or container instead of grouping them in a mixed bouquet. Vary the size and shape of the vases and containers and group them together to create a unique vignette.

All bouquets are beautiful.

Design trends

Living Fences when you Need to Screen

Variegated Mint Bush is a good addition to a living fence in sun or shade with foliage smells like a cross between mint, thyme and oregano.

Many people only think of plants that remain evergreen when they need screening. However, if you use one-third deciduous plants to two-thirds broadleaf evergreens they will weave together and you won’t be able to tell where one leaves off and another begins. This makes mature hedges secure borders, especially if you throw a few barberries or other prickly plant into the mix. You’ll also get seasonal interest with fall color and berries for wildlife.

When you plant new shrubs that you plan to turn into a hedge, know what to expect and then let each plant develop in its own way rather than trying to make it into something it’s not. Any plant can be pruned and trained into any shape but that creates more work than if you selected shrubs than naturally grow into a form that pleases you.

Narrow spaces can be challenging when you need to screen the house next door. There’s not room for a big, evergreen tree or hedge to solve the problem. One way is to use plants that can be espaliered against a fence or trellis. Some plants like azara microphylla naturally grow flat without much coaxing on your part. This small dainty tree is fast growing and reaches 15-25 ft tall. The yellow flower clusters will fill your garden with the scent of white chocolate in late winter. They are ideal between structures. I’ve used the variegated version to screen a shower and it’s working great.

Many times a screen may start in the sun but end up in mostly shade. For your sunnier spots why not mix in a few dwarf fruit trees to enjoy, ceanothus and Pacific wax myrtle for the birds, barberry for the beautiful foliage and fall color, spirea, rockrose, escallonia and quince for their bright flowers and fragrant lilacs for cutting in the spring?

Loropetalum chinense makes a beautiful low water screen in sun or part shade

The shadier side can include Oregon grape for fragrant, yellow winter flowers, snowberry for those striking white berries in the fall, oak-leaf hydrangea, viburnum and native mock orange for blossoms in the spring. Loropetalum have beautiful flowers and burgundy foliage while Variegated Mint Bush sport lovely purple flowers and fragrant foliage. Mixed hedges appeal to bees, butterflies and songbirds while also providing flowers, berries and color throughout the year for you to enjoy.

Good shrubs for screening that naturally stay between 6-15 feet include California natives such as ceanothus ‘Concha’ or “Julia Phelps’, California coffeeberry and mahonia. Other good performers are westringia ‘Wynabbie Gem’, New Zealand tea tree, oleander, pittosporum ‘Marjorie Channon’, purple hopseed and escallonia.

Bare spots in a hedge are caused by old age and repeated shearing without allowing the hedge to grow. The problem can be alleviated by cutting away dead twigs, branch by branch and then shearing outside the last cut next time you prune.

To keep down maintenance, mulch around your plants and install drip irrigation. There won’t be any pruning to do if you choose plants that grow to the height you want.

How close should you plant a mixed hedge? Depending on the mature size of the plant, spacing could be from 3-5 feet part If you want a quick, thick screen.This gives them room to breathe and develop their own shapes. Fast growing plants can be space 5-6 feet apart or more and will usually fill in within 5 years.

Provide the best growing environment for the fastest results. By this I mean amending the soil at planting time if your soil is not very fertile. Cover the soil with mulch and fertilize with compost or organic fertilizer. Water deeply when needed especially during the first three years when young plants put on a lot of growth. Formal hedges are fine for some gardens but think of all the added benefits you’ll get planting a mixed hedge.

Design trends

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.