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California Native Plants, Deer Resistant Plants, poisonous plants

Poisonous Natives / Deer Resistant Natives

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July already. Plants are growing like there's no tomorrow. The hummingbirds are my constant companions in the garden and the resident deer population comes by daily. There are two spotted fawns that now accompany their mother along with a couple of her sisters. Life is good.

I see them sampling plants what the older deer are trying. There are native plants that are poisonous for us but only some of them are avoided by deer. It got me thinking. How do deer eat poisonous plants without apparent ill affect?  

Deer are browsers. They thrive on a mixed diet. You've seen them eat a few roses then saunter over to the abutilon and then on to the daylily flowers. Deer will eat almost anything, even plants with a strong scent like catmint, lavender,  or thyme when they are hungry or need water. They can even eat a few bites of various toxic plants.

According to Tom Hanley,  a wildlife biologist with the Forest Service Pacific Northwest Research Station, "There seems to be threshold levels for the toxicity of different plants, and as long as deer eat below that threshold, they're okay."  Plant toxicity varies with the time of year also and flowers may be less toxic than leaves or roots. They just mix it up.

That explains the eating habits of deer but what about us?

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.

Mostly though, native plants make great additions to the garden. They tend to be well behaved and are rarely invasive. Birds and butterflies rely on them for food, shelter and nesting. And best of all they are beautiful.

When I'm designing with native plants I find the following plants are fairly safe around deer. They are not perfectly safe at all times of the year but they are usually avoided.

Artemisia also called Ca. sagebrush
Asarum – Wild ginger
Baccharis – Dwf coyote brush
Ceanothus  'Julia Phelps'
Eriogonum – Ca. buckwheat
Douglas iris
Mimulus auritanicus – Sticky monkey flower
Monardella – Coyote mint
Ribes speciosum – Fuchsia-flowering gooseberry
Salvia

Enjoy your garden. Let the deer browse elsewhere and be aware of plants that may be toxic to children.

 

pests, poisonous plants

Rhododendrons and other Poisonous Plants

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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.