Rhododendrons and other Poisonous Plants

My fascination with poisonous plants was piqued recently while researching organic methods for eliminating rhododendron root weevils. You’ve probably seen their damage-scalloped or notched leaf margins starting in May or June. The adult weevils feed at night but usually do not seriously injure the plant. It’s the larvae feeding unseen on roots that will cause severe damage and death of the plant if weevils are left uncontrolled.

Because rhododendrons contain toxic resins that are more concentrated in the foliage, to pesticides along with a tolerance for the toxins in the leaves. Organic or even chemical sprays have little effect anymore according to a study funded by the Rhododendron Society of America and end up killing hundreds more predatory beetles and other beneficial insects in the process.

Applying parasitic nematodes to your soil is one way to control weevils. Other tactics include placing a shallow pan of water under the plant or a soup can filled with soapy water buried up to the to attract and drown the adults . You can also try banding the trunks with tape or waterproof paper and smearing the bands with a sticky barrier like Tanglefoot. Spreading some coffee grounds under the plants also helps to discourage them from crawling up the trunk after they spend the night at the base of the plant. And if you’re really determined you can hand pick them after dark- effective but not much fun.

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.

Great Shrubs-not the ‘usual suspects’

Everybody has them. Some are burgundy, while some are variegated with fragrant flowers. I’m talking about shrubs that provide reliable good looks without a lot of work. Plants that have high impact, are low maintenance and contribute year-round interest should be the stars of your garden. Perennials are pretty but shrubs provide long term beauty without all the work. Here are some shrubs that I use often in designs. Shrubs I couldn’t live without.

Shrubs can be problem solvers. Let’s say you have a bare spot between you and the neighbor next door. The neighbor is nice and all but still you’d rather they didn’t look right into your kitchen window. You want a shrub with some pizazz as you will see it daily when you’re doing dishes. You’d like something different than the usual suspects for screening.

A wonderful plant for this spot would be Lophomyrtus Sundae. This evergreen, myrtle relative grows in full sun or partial shade and requires only moderate watering. Showy, creamy variegated leaves on burgundy stems make this narrow 8-12 ft tall by 4-8 ft wide shrub really stand out in the border. Small white summer flowers are an added bonus.

Need a fast growing, deer resistant, drought tolerant evergreen shrub for a sunny spot? Luma apiculata reaches 6-8 ft tall in no time and can even be trained as a small tree. Dense, deep green leaves, beautiful smooth bark and white to pinkish late summer flowers all make this plant valuable in the landscape. Birds will like the blue-black, half inch fruits although they are not especially tasty to us.

What tolerates considerable shade, blooms with fluffy yellow flowers that smell like chocolate or vanilla and is dense enough to make a good screen or informal hedge?  Azare dentata grows to 15 ft tall, 12 feet wide and can also be trained as a small tree if you want. It would combine well with other tall shrubs in the shady border like Lily-of-the-Valley shrub, podocarpus Maki, hydrangea, Japanese aucuba, mahonia and rhododendron.

Another shrub to ignite a border with smoldering shades of burgundy and purple is the Royal Purple smoke bush. Their stems grow straight up which makes them a useful addition to any border in need of diverse forms. Growing up to 15 ft tall and wide, you can keep this drought tolerant plant in check by cutting back hard each spring after the first leaves break out. They will send up new growth year after year. If left unpruned, wispy, smoky flower clusters appear in spring. Even the youngest specimens turn a striking burnished orange-red in fall. They grow in full sun or partial shade.

There are so many  interesting, easy to grow shrubs. Any one of these will earn its keep with good foliage, interesting form and low maintenance.

Watering tips for Santa Cruz Mountain Gardens

Summer is in full swing now and you may be torn between reading a book on the chaise lounge or pruning the wisteria. Actually, it’s important to do both. Watering is crucial also as plants are vigorously growing and the warmer weather evaporates available soil moisture quickly.

Ignore generalities such as "provide one inch of water each week" or "don’t water at midday,the leaves will burn". Instead, become aware of your garden’s moisture needs. Hot, sunny, windy slopes or shady beds with clay soil and new plantings all require a different watering strategy.

When is the best time to water? Is it true that water droplets will scorch leaves in the sun? According to a study published in New Phytologist, a journal of research in plant science, there is a slight risk of leaf burn on fuzzy leaved plants like ferns. The hairs can hold the water droplets above the leaf surface and act as a magnifying glass to the light beaming through them. The study also reported that water droplets on smooth leaves, such as maples, cannot cause leaf burn, regardless of the time of day.

However, in my thirty years of gardening , my own observation is that the leaf burn on a fuzzy leaf must be very small, indeed, as I’ve never observed any damage. If you find a plant needs water midday, by all means go ahead and water it. Containers even benefit from the cooling effect that watering provides.

That being said, watering in the morning is the most efficient whether you water by sprinkler, drip system, soaker hose or by hand. The water soaks deep in the soil without risk of evaporation. It bolster the plant for the day and has dried from leaves by evening reducing the risk for foliar diseases like mildew. Plant roots are also more receptive to watering in the morning.

Water makes up 90-98% of every plant we grow. It’s needed for photosynthesis, as well as reproduction and defense against pests. Checking soil moisture and improving a soils ability to absorb and hold water should be a priority when you’re out in the garden. Don’t wait for plants to wilt and burn before correcting watering problems.

Most plants need 18" depth of well-drained soil to thrive although trees and many vegetables roots grow several feet deep. More than an inch of water per week may be needed for their success and in the case of many trees and native plants, deeper but more infrequent watering is required.

You can easily measure how much water you are applying. If you have a sprinkler system, place a straight-sided container like a tuna can on the outside edge of the area being watered. Let the sprinkler run until one inch of water has accumulated in the can. When using a drip system or soaker hose, irrigate until a 3" deep test hole dug 1 ft out from the emitter or end of the soaker is moist. Moisture at that level indicates than an inch of water has been applied. The best way to determine how many inches of water your soil needs for a good soak is by digging down after the water has had a chance to settle. When watered well, the soil should feel cool and damp at the bottom of the hole. If the soil feels warm and dry you haven’t watered long enough. You need to do this test just once to get a feeling for how much water your soil can hold and how deeply it’s soaking in.

Be kind to your plants this summer. It only take a few minutes for a drop of water suspended form a soil particle to be drawn upward from a root tip to the farthest leaf blade and then released from leaf stomata as air cooling vapor. How cool it that?

Butterflies of the Santa Cruz Mountains

Have you noticed how many butterflies are visiting your garden lately?   I see California Sister, Common Buckeye and Western Tiger Swallowtail everywhere I look. We have about area. Many of these occur only in our mountains, forests and chaparral environments. They are easy to attract and make a permanent feature of your landscape. Here’s how.

Butterflies are less efficient than bees as pollinators but have their place in the ecosystem. They do not pick up much pollen on their bodies. Still they visit a variety of wildflowers and other plants to probe for nectar adding beauty and color to the garden. Did you know that butterflies taste with their feet?

To attract the species of butterfly most common in your area, a butterfly garden should include plants that accommodate all stages of the life cycle ( egg, larvae, pupa and adult ). When both adult nectar and larval host plants are available, they will attract and support a butterfly population. In addition to the right plants, your garden should also have sun, a water source, protection from wind and plants in clusters. When maintaining your garden avoid the use of insecticides, including BT.

As adults, most butterflies feed on the nectar of flowers. Some local butterflies, however, like the Mourning Cloak and Red Admiral, feed primarily on rotting fruit or tree sap for moisture and nutrients and the California Sister also feeds on aphid honeydew.

In the larval stage, most butterfly species are limited to a single plant family and occasionally a single genus. To attract more Western Tiger Swallowtails, for instance, provide larval host plants such as willow, sycamore, alder, Big Leaf maple, sycamore, plum and ash. Common Buckeye lay their eggs on mimulus and verbena while California Sister use the coast and canyon live oak. Planting a variety of grasses and shrubs like ceanothus, buckwheat, coffeeberry, bush lupine and manzanita and also perennials like redwood violet, California aster and wallflower to attract a variety of local butterflies. If your garden is near a wild area that naturally supports the caterpillar stage, you can plant just the nectar plants to attract butterflies to your garden.

Filling your garden with nectar producing flowers is the fun part. Adult butterflies rely on sugar-rich nectar for their daily fuel. Different species have different flower color and shape preferences. Many butterflies produce scents that attract the opposite sex and many of these scents smell like the flowers that they are attracted to and visit. The scent of these butterfly pollinated flowers may have evolved as an adaptation to ensure their survival.

Butterflies typically favor flat, clustered flowers that provide a landing pad although larger butterflies can feed on penstemon and salvias while hovering. Butterflies have good vision but a weak sense of smell. Unlike bees, butterflies can see red and are attracted to brightly colored flowers. PInk, red, orange, yellow and purple are the most attractive nectar source colors but they also use blue and white.

Consider the blooming time of each plant. Having plants blooming in the sun for many hours in the day will lengthen your viewing time. Nectar rich flowers include yarrow, aster, verbena, scabiosa, buckwheat, toyon, salvia, erysimum, zinnia, lantana and coneflower.

In addition to nectar, butterflies need a source of water and salts. A patch of mud kept wet year round or a shallow depression lined with pebbles and kept moist will work fine. Also provide some flat rocks for them to bask in the sun in an area protected from the wind by shrubs.

Having your own butterfly garden will enable you to witness close-up the wonder of butterflies and the flowers on which they feed.
 

Tropical Plants for the Santa Cruz Mountains

Summer weather is finally here and I find myself thinking of ways to stay cool. We know there is a cooling effect under the canopy of our forest trees. Extremes in air and soil temperatures are lessened. But any combination of perennials, shrubs and trees helps to keep your garden cool while also providing habitat for wildlife, decreasing energy usage, absorbing CO2 and supplying fresh oxygen. Why not add some plants that have a tropical feel to make your garden feel and look soothing on a hot summer day?

Bold, large scale plants with dramatic foliage evoke the jungle. Mixing the familiar with the exotic creates dramatic compositions. Hardy tropical gardens are based on rhythmic repetitions of plant form and foliage patterns rather than on a flowers. Flowers do play their part but it is the flow and interplay of shapes and textures that form the design and create ongoing visual interest.

Start by adding a tree that is big and bold like Purple catalpa. Catalpas are among the few hardy deciduous trees that can compete in flower and leaf with sub tropical species. Huge leaves, 10-12" long, emerge deep blackish purple in spring, then turn purplish green in summer. At this time of year, the tree is covered with large clusters of white trumpet shaped flowers lightly speckled with yellow or purple. At 30-40 ft tall, this beautiful tree is well adapted to extremes of heat and cold as well as different soils.

You’re probably not going to be ripping out your old garden and starting anew, but you can revise your plant palette to include hardy tropicals. Even if your garden is small, using just a few outsize, large textured plants gives a neutral small space an immediate sense of intimacy. Emphatic foliage plants like Japanese aralia, philodendron selloum, black bamboo, red banana, windmill palm or canna lily would make a dramatic statement in any garden. Canna Australia is especially showy. This burgundy-leaved cultivar is often grown for its foliage alone though it bears spectacular orange-red flowers in summer. Plant in full sun or part shade in average soil and supply regular water during growth and bloom.

Sculptural plants instantly transport us to the wild. Richly colored foliage and bold shapes add a lush feeling to the understory of your tropical garden. Here’s where the chartreuse leaves of Sum and Substance hosta really stand out. This 3 ft high by 6 ft wide variety can handle some sun. Pale lavender flowers spikes are an added bonus. Combine it with the striking, creamy yellow, variegated abutilon Thompsonii. It blooms almost continually with pale orange bells veined with red. The hummingbirds will love you.

Underneath it all, plant some showy groundcovers like black mondo grass, lysimachia Goldilocks, lamium Pink Pewter or Burgundy Glow ajuga.

Whatever you choose, see your garden anew and enjoy the summer in a cooler topical garden.

Color in the Garden

Now that the weather is cooperating it’s a pleasure to spend time out on the deck and in the garden. Even the evenings are warm enough to enjoy outside. If you find yourself looking about and thinking the garden of your dreams needs a little something more, consider adding color from flowers, foliage, bark and landscaping materials.

Don’t be afraid to play with color even if you don’t get it right the first time. Just learn from your mistakes and make adjustments. Whether it’s a pastel Monet garden or a hot Samba garden you want to create, here’s how your own garden can draw oohs and aahs in every season.

Warm colors , dynamic and noticeable from afar than cool hues which are more calming and understated. Warm colors advance visually, cool ones recede. So to make a small garden appear larger use cool blues and lavenders in the back with just a touch of scarlet, orange or yellow up close for contrast. Do the opposite to make a large space more intimate – position warm colors at the back, cool colors in front.

Garden colors aren’t static either. They vary with time of day, the season, the weather and the distance from which we view them. Also color perception varies among people and not all people with normal vision see color the same way. Since color and light are inseparable, white, yellow and pastels seem more vivid in low light. In overcast or fog, soft colors like pink, creamy yellow, pale blue and lavender come alive. As night approaches and the earth is bathed in blues and violets, those colors are the first to fade from view.

Have fun with color. don’t be afraid to try new combinations. . I often hear people say "I like all the colors except orange". Orange naturally combines with blue as these ‘sunset’ colors are opposite each other on the color wheel. Think how nice bright orange California poppies look with blue marguerites or peach poppies with blue violas. You might not think of linking orange with pink but it’s a pleasing combination. It works because pink is analogous with purple. Try combining orange calibrachoa in a planter with pink arctotis and lavender Silver Sky bacopa to harmonize with the pink and contrast with the orange.

Foliage is a rich source or garden color. You can find plants with yellow, red, purple, blue or gray foliage as well as shades of green with variegated, marbled or streaked leaves. Rose Glow barberry has rich marbled bronzy red and pinkish hew foliage and looks sensational next to coral Grosser Sorten pelargoniums.

And don’t forget white, cream and silver flowers and foliage to brighten up the night garden. White combines nicely with both warm and cool colors so it’s easy to place. It’s an effective peacemaker between colors that would clash if placed side by side. In shady gardens, plants like white bleeding heart, wavy cream-edged hosta, white browallia, white hydrangea, lamium and white calla lily pop at night. Gardens in more sun can plant Holly’s White penstemon, silvery bush morning glory, dichondra Silver Falls, fragrant Iceberg roses and white sweet alyssum and Whirling Butterflies gaura for the butterflies.

Plants grow and gardens change over time. Realize that you’re embarking on a journey that may take many years. Have fun getting there.

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