Category Archives: pests

methods for controlling pests

pests

How to Combat Moles and other Critters in the Garden

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There’s a gentle guy among us with a beautiful garden in Scotts Valley who’s a serial killer – a killer of moles, that is. "The first one’s the toughest"  he said while showing me around the other day. Caddyshack has nothing on this determined gardener and from the look of his landscaping he’s definitely winning the battle.

This mild mannered vegetarian started planting trees 20 years ago when he moved to the property but says he became serious about gardening only 5 years ago. He has created lush-looking, low water landscaping in his extremely sandy soil, watering some areas only once per summer. And oh, did I mention, he shares his garden with deer, too?

Many of us battle some of these same issues. How does he win the war while watching his garden grow? He used to have gophers, too, but after using cinch and Macabee traps for the past couple of years there are not too many left on the property. The moles are a different story. They have the ability to learn testing our mental prowess in the process.

He has found that one of the best ways to keep moles from destroying his garden is to install perimeter fencing around the beds. Gardening by exclusion he calls it. Cinch traps are successful, too, and he’s killed 16 so far this year. It’s not that the moles eat the plants but their burrowing dislodges roots and the plants will die the next time it gets hot. He digs down 24" and sinks a gopher wire barrier, one area at a time.  Paths are left bare so he can see if they are encroaching. Moles can tunnel 17 hours a day and ruin an area in just a couple of hours so he has become ever vigilant.

Deer control comes from plant selection and a product he gets on the internet that contains a bittering agent found in antifreeze, anti-nail biting and cleaning products among other household items.  Having used other taste and smell repellents containing rotten eggs, garlic, blood meal, citrus, ammonia, hot pepper and coyote urine, he swears by this product. His garden contains many plants he considers "bullet proof" like lambs ears, lions tail, hot lips salvia, breath of heaven, tagetes, armeria, asteriscus, carnations, dietes, Little John callistemon, mimulus, westringea and society garlic to name just a few. He plants "what works".

What hasn’t worked with his deer population is vinca that used to grow under the oaks. Wandering jew has successfully taken over and he’s OK with that. "Why fight it?" is his mantra. Plants he protects with Bitrex are daylily flowers, star jasmine, correa, penstemon, some sedums and the flowers on the aloe. He grows lots of different aloes, yucca and agaves, rescuing many from garbage piles and propagating others. He has 4 acres to cover.  There’s also a huge Angel’s trumpet under the oaks that he started from a cutting 4 years ago.

In one garden a huge Breath of Heaven has grown 9 ft tall. Nearby is a handsome small tree from So. Africa, Podocarpus henkelii or Long-leafed Yellow-wood. Eventually it will grow to 25 ft but is only half that size now. The foliage is distinctive and dense with heavy, shiny, dark green drooping leaves, giving it a weeping look. It is truly a specimen tree. His euphorbia collection includes a variety that looks like an azalea with chartreuse flowers. A very large stand of crocosmia was started from a 4" pot. Fortunately it’s planted in the right spot.

So much to see, so little time. Everywhere I looked was another beautiful vignette- accenting a dry river bed in one area, a fire pit with log seating in another. I learned so much from this gentle, determined gardener.

pests

Spider Mites

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That’s a good question
If you notice the leaves on some of your plants appear stippled or flecked with pale dots and have fine webbing, especially on the undersides, you have a spider mite infestation. These pests thrive during dry weather and their populations can get out of hand by August.

Mites puncture plant cells with their mouthparts, then suck the plant fluid. The tiny areas of leaf tissue that have been killed appear as tiny dots on the the leaves. Mites often go unnoticed because they are tiny and natural controls such as weather and predators frequently keep their populations low. Severe infestations often result because these natural controls have been disrupted by pesticides and excessive dust.

Control spider mites on fruit and nut trees, azalea, fuchsia, maples and rose by regular, forceful spraying of plants with water to rinse dust and dirt off both sides of leaves. If you do have to spray to control an outbreak use insecticidal soap or a light spray oil. Sulfur is effective in reducing populations of some spider mites but this dust can disrupt beneficial predaceous mites.

Avoid using broad-spectrum pesticides which disrupt biological controls. When applied for other pests during hot weather, these can cause dramatic outbreaks of mites within just a few days even though their label may say they control mites.

Although a young or weak plant may not survive a severe spider mite infestation, it is not usually fatal to a vigorously growing tree or plant. The best defense is a good offense – periodically spray your plants with water in the morning to keep them clean and dust free.

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.