Sacramento Digs Gardening logo
Sacramento Digs Gardening Article
Your resource for Sacramento-area gardening news, tips and events

Articles Recipe Index Keyword Index Calendar Twitter Facebook Instagram About Us Contact Us

Is there a cure for spider mites?

Grab the hose to fight these dust-loving pests

Multicolored oval tomatoes with mite damage
Look closely to spot the mite damage on this Brad's Atomic Grape tomato plant. It's especially evident around the sepals (green "caps") of the tomatoes. Water is your best weapon against spider mites. (Photo: Kathy Morrison)



Hot weather, smoky skies, dusty plants and no rain in sight: That’s paradise for spider mites.

With prolonged dry heat, this summer has seen a spider mite explosion. The itty-bitty arachnids seem to be spinning their webs over everything: Tomatoes, roses, camellias, berries, fruit trees, you name it.

A cousin of spiders, spider mites have built up massive populations in local community gardens as well as backyards. Usually, natural enemies can keep these voracious critters under control. But right now, spider mites are having a baby boom.

Spider mites can produce a whole generation in five to 10 days. Each mama mite can lay 100 eggs. No wonder their numbers can overwhelm a plant in a short time.

Spider mites are so tiny – smaller than the period at the end of this sentence – gardeners usually don’t notice them until they’re mature; that’s when they start spinning their telltale webs.

As they grow, they tend to hide out on the underside of foliage, practically invisible to even the most observant gardeners. Spider mite feeding may cause polka-dot stippling to appear on leaves.

According to the UC Cooperative Extension master gardeners, spider mites attack many fruit trees, shrubs, vines, berries, vegetables and other ornamental plants. Besides tomatoes and roses, they also love beans, grapevines, squash and melons.

The damage at first looks a little like peach leaf curl with foliage developing stipples and turning yellow or red before falling off. Then the webs start appearing, coating leaves and stems.

If left undisturbed, spider mites can overwhelm plants. They’re especially bad during drought conditions (like right now) and can do the most harm to water-stressed plants.

Spider mites can’t be controlled by insecticides – they’re not an insect, they’re a mite. But miticides are not recommended either, since they kill many beneficial insects in addition to the mites, which often manage to evade pesticide sprays.

Neem oil applied in the early stages of an infestation may smother the mites, but also kills beneficial insects including those that eat mites. In addition, neem oil sprayed on hot days can cook the plant’s foliage – eliminating any benefit.

Instead of neem oil or miticides, grab a hose and make it “rain.” Spider mites are proliferating because of lack of rain and resulting dusty, dry conditions on plants. Washing down foliage mimics a summer storm and disrupts the mites’ happy homes.

Insecticidal soap also can be helpful if applied at the first signs of trouble. Make sure to spray the underside of leaves, too.

The good news? Spider mites usually die out in September when their natural enemies can keep their numbers in check. Until then, keep giving plants a gentle morning shower as needed to wash dust and mites away.

For more advice, see the UC IPM pest notes on spider mites:
http://ipm.ucanr.edu/PMG/PESTNOTES/pn7405.html

Comments

0 comments have been posted.

Newsletter Subscription

Sacramento Digs Gardening to your inbox.

Taste Winter! E-cookbook

Lemon coconut pancakes

Find our winter recipes here!

Local News

Ad for California Local

Thanks to our sponsor!

Summer Strong ad for BeWaterSmart.info

Dig In: Garden Checklist

For week of March 3:

* Celebrate the city flower! Catch the 100th Sacramento Camellia Show 3 to 6 p.m. Saturday, March 2, and 10 a.m to 5 p.m. Sunday, March 3, at the Scottish Rite Center, 6151 H St., Sacramento. Admission is free.

* Between showers, pick up fallen camellia blooms; that helps cut down on the spread of blossom blight that prematurely browns petals.

* Feed camellias after they bloom with fertilizer formulated for acid-loving plants.

* Camellias need little pruning. Remove dead wood and shape, if necessary.

* Tread lightly or not at all on wet ground; it compacts soil.

* Avoid digging in wet soil, too; wait until it clumps in your hand but doesn’t feel squishy.

* Note spots in your garden that stay wet after storms; improve drainage with the addition of organic matter such as compost.

* Keep an eye out for leaning trunks or ground disturbances around a tree’s base, a sign of shifting roots in the wet soil.

* Fertilize roses, annual flowers and berries as spring growth begins to appear.

* If aphids are attracted to new growth, knock them off with a strong spray of water or insecticidal soap. To make your own “bug soap,” use two tablespoons liquid soap – not detergent – to one quart water in a spray bottle. Shake it up before use. Among the liquid soaps that seem most effective are Dr. Bronner’s Pure-Castile Soaps; try the peppermint scent.

* Pull weeds now! Don’t let them get started. Take a hoe and whack them as soon as they sprout.

* Prune and fertilize spring-flowering shrubs after bloom.

* Cut back and fertilize perennial herbs to encourage new growth.

* Make plans for your summer garden. Once the soil is ready, start adding amendments such as compost.

* Indoors, start seeds for summer favorites such as tomatoes, peppers and squash as well as summer flowers.

Taste Spring! E-cookbook

Strawberries

Find our spring recipes here!

Taste Summer! E-cookbook

square-tomatoes-plate.jpg

Find our summer recipes here!

Taste Fall! E-cookbook

Muffins and pumpkin

Find our fall recipes here!