From the UC Blogosphere...

Pests in the Garden

By Yvonne Rasmussen, U. C. Master Gardener

The recent nice weather has made everyone more active in the garden, including the insects. Some insects, although large and rather dramatic, are not serious pests in the garden, while other smaller ones can be very problematic, especially if they are new to our area.

The large, white, C-shaped grub with a brown head and gray tail may be big—it measures about one inch long—but it does no harm in the garden. It is the larval stage of a scarab beetle called the masked chafer or, alternatively, the May or June beetle. It generally matures in May or June and is rarely a pest unless it is in your lawn. In lawns, these grubs can cause brown spots where they eat grass roots. In your garden soil, you can ignore them or remove them by hand. Toss them onto a dry surface, where they will dehydrate and die. Often birds will eat them.

On the other hand, the spotted winged drosophila (SWD) is a minute insect that can ruin your fruit crop. First spotted in California three years ago, it is a serious invasive fly. It has since spread to all the fruit-producing areas of California, Oregon and Washington.  It is related to the vinegar fly that likes the overripe fruit on your kitchen counter, but this fly attacks ripening fruit.

The male has two spots on the tip of its wings. The female lays her eggs in whole ripe fruit. This insect is a big concern for anyone growing soft fruits such as cherries, raspberries, blackberries, blueberries, strawberries, plums, nectarines and peaches. It thrives in temperatures from 70°F to 80°F, with high humidity, so coastal crops and early-season fruits are most at risk.

The damage makes it possible for fungi to get into the fruit, which accelerates the rotting process. Only two to three days after the female lays her eggs inside, the fruit will start to collapse and wrinkle. So how can you protect your fruit?

 Here are a few tips for homeowners:

 Set up monitoring traps early in the season, which means now. You can make traps easily from heavy plastic 16-ounce or 32-ounce cups with tight-fitting lids. Drill small holes (1/16 to 3/8 inch) along the top sides. Fill the cup with about two inches of cider vinegar and one drop of dish soap. Place a yellow sticky card (available at many nurseries and hardware stores) loosely arched inside near the top to trap flies. Hang the trap in a tree near the fruit, or place it on the ground in a cool, shady spot. Check traps weekly to collect the flies from the liquid and the sticky card. You will likely catch several kinds of flies; use a magnifying hand lens to identify the SWDs. Even if you don’t identify the flies you catch, you can use these traps to help reduce the fly population around your fruit trees or bushes.

 Use fine netting to keep flies away from fruit before it begins to ripen. You can build a cage around your trees to keep out the flies, but make sure it has no gaps or holes and make sure your netting is very fine.  These flies are really small. The same netting will protect fruit from bird damage, too.

 Pick ripe fruit frequently. Flies attack soft ripe fruit, so harvest several times a week to make sure you get to eat it before they do.

 Clean up and destroy all fallen fruit and do not leave any overripe fruit on the tree or plant.

 A few pesticides are available for home use. Follow the label directions carefully and do not spray when bees are active.

 Napa County Master Gardeners will be hosting two workshops this summer on insects in the garden. On Saturday, June 18, “Debugging Garden Bugs” will offer tips for insect identification. On Thursday, June 23, “Get to Know Your Garden Bugs” will present a more general program designed for families.

For more information on controlling the spotted winged drosophila, visit our website (see below). Look under Napa County Programs for Master Gardeners, then under Seasonal Topics for the information on SWD, or come by our office for complete information.

Master Gardeners are volunteers who help the University of California reach the gardening public with home gardening information. Napa County Master Gardeners (http://cenapa.ucdavis.edu) are available to answer gardening questions in person or by phone, Monday, Wednesday and Friday, 9 a.m. to Noon, at the U. C. Cooperative Extension office, 1710 Soscol Avenue, Suite 4, Napa, 707-253-4221, or from outside City of Napa toll-free at 877-279-3065. Or e-mail your garden questions by following the guidelines on our web site. Click on Napa, then on Have Garden Questions?

U.C. Master Gardener TV is broadcast weekly on Napa Public Access Cable Television Channel 28, and ATT U-Verse Chanel 99, at 11 a.m. on Thursdays and 7 p.m. on Saturdays. You can also watch it online at www.napavalleytv.org. .

Garden Tour: Save Sunday, May 15, for “Down the Garden Path,” the Napa County Master Gardeners’ garden tour. The tour will showcase seven unique Up Valley gardens owned and maintained by local Master Gardeners. For tickets and more information, visit http://cenapa.ucdavis.edu.

Mobile Help Desk: Bring your gardening questions to the Napa County Master Gardeners mobile help desk on Saturday, April 23, at Mid-City Nursery in American Canyon; and Saturday, April 30, and Sunday, May 1,  at DJ’s Growing Place in Napa. Master Gardeners will be available to answer questions at these locations from 10 a.m. to 2 p.m.

Open Garden Days: Napa County Master Gardeners welcome the public to their demonstration garden at Connolly Ranch on the first Thursday of every month, from April through October, from 10:30 a.m. to noon. Master Gardeners will be on hand to answer questions. Connolly Ranch is at 3141 Browns Valley Road in Napa.

Fiddle De-Dee!

Nero may have fiddled while Rome burned, but the honey bees just kept on working. We recently visited an apiary in Glenn...

Honey bee settles on a fiddleneck. (Photo by Kathy Keatley Garvey)

Honey bee settles on a fiddleneck. (Photo by Kathy Keatley Garvey)

A taste of nectar--honey bee on a fiddleneck. (Photo by Kathy Keatley Garvey)

A taste of nectar--honey bee on a fiddleneck. (Photo by Kathy Keatley Garvey)

Come on in--the nectar's fine. (Photo by Kathy Keatley Garvey)

Come on in--the nectar's fine. (Photo by Kathy Keatley Garvey)

Poolside Plants

By Cheryl Toivola, U. C. Master Gardener

Choosing plants to be used around swimming pools is a more complex task than just choosing plants that look tropical. Poolside plant choices should be determined by factors such as microclimate, pest tolerance and litter potential, as well as the safety and comfort of the pool users.

Avoid any plants with stickers, thorns or anything bristly or sharp. The pool deck is an active area and often host to playing children who do not want to be cut, poked or scratched. Pool-area plants also need to be hardy so that a poorly thrown pool toy doesn’t cause damage. 

Keep plants that attract stinging or annoying insects away from the pool, and avoid plants prone to pests or disease. You don’t want to have to spray pesticides or herbicides around pool water.

For easy maintenance, choose plants that produce minimal litter or debris. Avoid deciduous plants whose leaves could drop or blow into your pool. Deciduous fruit trees do not belong anywhere near a pool as they will drop not only their leaves but rotting fruit as well. Do not plant trees with invasive roots. Over time, these roots can lift up a pool deck.

Several evergreen trees can also create irritating liter. Coast live oak drops acorns, and many varieties of pine drop needles. This debris can also stain a concrete pool deck.

Many perennials can also be messy, so consider annuals in beds located close to the pool. Pick annuals that will hold their petals and leaves such as zinnias. Avoid messy bloomers such as petunias and geraniums. 

Plants can serve many purposes in poolside landscaping. They can help soften the harsh lines of the pool and deck. Plants can also screen unsightly pool equipment, cover fences or create privacy screens.

Although the list of plants unsuitable around a swimming pool seems long, many good choices remain. To make a statement, choose dramatic plants. These plants can create even more drama if they are placed close enough to cast a reflection onto the pool. Plants with a dramatic look include agave, yucca, phormium and palms.  Agaves need frost protection but can add a sculptural accent. Saga palm creates an attractive tropical effect without the litter of palm fronds.  For shaded areas, Fatsia japonica (Japanese aralia) can create a bold look.

If showy flowers create too much litter, choose plants with colorful, bold leaves. Many phormiums (New Zealand flax) have large, narrow, fleshy  leaves striped with pink, green or yellow. Especially colorful varieties include ‘Rainbow Warrior’, ‘Jester’, ‘Maori Chief’ and ‘Sundowner’. 

A quintessential favorite that can be found near many California swimming pools is Agapanthus africanus (lily of the Nile). This South African native has many cultivars ranging in bloom color from white to blue to purple.  There is also a dwarf variety called ‘Peter Pan’.

For small shrubs, plant low-litter varieties such as Pittosporum tobira ‘Wheeler’s Dwarf’, Nandina domestica ‘Gulf Stream’, Raphiolepsis indica ‘Ballerina’ or Viburnum davidii.  For additional color, try perennials such as Hemerocallis (daylily), Erysimum ‘Bowles Mauve’ (wallflower), canna or Kniphofia (red hot poker). Additional annual choices include begonia and coleus. 

The right plants can help you create an attractive, low-maintenance, litter-free environment around your swimming pool. For a more comprehensive listing, consult Sunset’s Western Garden Book.

U.C. Master Gardener TV is broadcast weekly on Napa Public Access Cable Television Channel 28, and ATT U-Verse Chanel 99, at 11 a.m. on Thursdays and 7 p.m. on Saturdays. You can also watch it online at www.napavalleytv.org.

Garden Tour: Save Sunday, May 15, for “Down the Garden Path,” the Napa County Master Gardeners’ garden tour. The tour will showcase seven unique Up Valley gardens owned and maintained by local Master Gardeners. For tickets and more information, visit http://cenapa.ucdavis.edu.

 

Gardening Helps Adult Day Care Members

By Jill Rowley, U. C. Master Gardener

What is horticultural therapy? If you were to visit the Napa Valley Hospice facility on Jefferson Street in south Napa, you would see an inspiring example. Nine volunteers, many of them Napa County Master Gardeners, spend time every week working with the clients of Adult Day Services. These clients are often physically frail. They may be stroke survivors or have early-stage dementia or Alzheimer’s or chronic mental-health issues. People come to the facility for its many services, one of which is horticultural therapy, held every Wednesday morning and every other Friday morning.

Not all the clients who use the center are interested in gardening, but about 25 participants enjoy the fresh air and the pleasure of watching seeds grow into full-sized plants. They also tend the perennials and keep the beds free of weeds.

Flowers, vegetables, succulents and herbs are all grown in planters within easy reach of the gardeners and accessible for wheelchair users. When I visited in early February, on a lovely warm day, I saw the Adult Day Services clients heading out to the patio, smiling and sporting huge sun hats. Some went to work digging and weeding the planters, some planting small lavenders that they had propagated themselves, and some just talking to other gardeners.

I learned that a cooking group at the center has used tomatoes and herbs grown by the clients to make salsa and the staff has used fruit from the lemon tree to make lemon bars.

In talking to coordinator Anne McMinn, I learned that the garden participants often show improvements in memory function and socialization. Sometimes a certain plant or fragrance will jog a memory. One of the garden beds has a sensory theme with fragrant plants such as lavender and lemon thyme. Once a year, the participants hold a plant sale, pricing and labeling the plants and helping to sell them. Last year's sale raised $250 for garden supplies.

The clients of Adult Day Services may need a little more help than others, but all of us reap the benefits of gardening. In the garden we get quite a workout, bending down to plant, reaching up to trim a bush, lifting mulch and potting soil, stretching to rake beds, and clenching and unclenching our hands to pull weeds.

It is important to bend the knees when lifting, letting the legs do the work, not the back. Bend from the hips, not the waist, when hoeing, digging or planting. Those with arthritis can use tools with large handles. Gardeners with weak backs should use long-handled tools and limit the time spent in the garden so as not to become too tired. 

Gardening is also mentally therapeutic. Just think of the pride you feel when your seeds germinate or when you see your bulbs poke up through the soil or watch a shrub develop its first flowers.  It is so enjoyable to share successes and failures with other gardeners, and so gratifying to taste fruits and vegetables that you have grown yourself.

Even those who are elderly, or not as physically able, can enhance their fitness by work in the garden. Gardening strengthens muscles and improves stamina, balance and coordination. Many studies have proved that muscle tension and blood pressure respond positively to plants, and that planning and planting a garden can provide respite from daily stresses and worries.

Horticultural therapy benefits people of all ages. Children can experience the delight of growing zucchini from seed. Adults can have the satisfaction of growing food for their daily meals. Seniors can work leisurely, cultivating the flowers or vegetables that they love. Gardening offers pleasures for a lifetime.

In the Napa Valley, we are fortunate to be surrounded by beauty. Every season brings visual pleasure, whether it is the daffodils, tulips and poppies along the roads, the mustard in the vineyards, the pink and white blossoming trees along our highways, the roses in our home gardens, or the bronzed autumn foliage on trees in the city parks. These sights give us a mental lift every year, but even greater pleasure can be found by working your own soil. Watching a garden grow can be the best feeling in the world.

Joseph Breck, a 19^th-century horticulturist, wrote, “'Man was not meant to rust out in idleness. A degree of exercise is necessary for the preservation of health, both of body and mind, as his daily food. And what exercise is more fitting, or more appropriate of one who is in the decline of life, than that of superintending a well-ordered garden?”

Garden Tour: Save Sunday, May 15, for “Down the Garden Path,” the Napa County Master Gardeners’ garden tour. The tour will showcase seven unique Up Valley gardens owned and maintained by local Master Gardeners. For tickets and more information, visit http://cenapa.ucdavis.edu.

Mobile Help Desk: Bring your gardening questions to the Napa County Master Gardeners mobile help desk on Saturday, April 9, and Sunday, April 10, at Home Depot in Napa; and Saturday, April 16, and Sunday, April 17, at Orchard Supply Hardware in Napa. Master Gardeners will be available to answer questions at these locations from 10 a.m. to 2 p.m.

Free Workshop: Join Napa County Master Gardeners for a workshop on “Containers and Raised Beds” on Saturday, April 16, from 10 a.m to noon at the University of California Cooperative Extension in Napa. Learn to maximize your limited space by growing ornamentals, herbs and vegetables in containers and raised beds. Regiser online: http://ucce.ucdavis.edu/survey/survey.cfm?surveynumber=5920.

Open Garden Days: Napa County Master Gardeners welcome the public to their demonstration garden at Connolly Ranch on the first Thursday of every month, from April through October, from 10:30 a.m. to noon. Master Gardeners will be on hand to answer questions. Connolly Ranch is at 3141 Browns Valley Road in Napa.

Sharpshooter Always a Concern

by Val Whitmyre, Master Gardener

At a recent Master Gardener meeting, Napa County agriculture commissioner Dave Whitmer was the featured speaker. He delivered a sobering, but optimistic, message.

Whitmer spoke of how the early Indians had talked together about preserving the beauty and health of their land for seven generations out. They couldn’t have imagined the need for certified organic vegetables or guaranteed free-range chicken. They had no notion of pollution, either, just the contentment of cooking the evening meal under the stars.

As Whitmer spoke, my mind fast forwarded to the present and images of polluted waterways, paved-over farms, chemical pesticides and herbicides and supermarkets full of produce from Chile.

In the early 1990s, I remember seeing ripped-out vineyards where, only a week before, had been a seemingly healthy expanse of green foliage. This devastation, caused by a miniscule root-louse, phylloxera, had infected several vineyards, prompting drastic action to prevent further infection.

There is no turning back to simpler times. Napa Valley has developed into a tourist destination because of our wines, and we have consequently become a mono-crop valley. So we have had to develop solutions to guard against other diseases and pests. We must be vigilant in monitoring and inspecting to keep predators out of our county.

Nature always has another challenge for us. One worry for our grape growers is the glassy-winged sharpshooter, a big, ugly leafhopper. As large as a dime, it has the unpleasant habit of sucking fluid from plant stems and excreting a white liquid so drippy that some liken it to rain.

The sharpshooter’s sucking may not even harm the plant seriously, but as the insect moves from one plant to the next, it spreads the bacteria that cause Pierce’s disease. As these bacteria multiply, they clog the plant’s water-conducting tissue, which can compromise or kill a grapevine. The sharpshooter flies fast and far and could quickly infect a whole vineyard or even a whole county.

This pest lays its eggs on the underside of leaves. Its hosts include grapevines, crape myrtle, sumac, oleander, almonds, oaks, hydrangeas and stone fruit. It particularly likes young grape leaves. Symptoms of Pierce’s disease include leaf wilt, leaf burn or browning, drying or premature leaf drop.

We can help control this devastating insect by regularly inspecting our trees and vines. We can remove suspect plants from our property. To keep the pest out of our county, buy from local nurseries. Buying plants online isn’t buying locally, nor is shopping in adjacent counties.

 Look for a certificate of compliance at your local nursery, which indicates that the nursery is inspecting incoming plants. If you think you have spotted this sharpshooter, call 866-BUG-SPOT or visit bugspot.org to learn how to report the sighting.

The European grapevine moth is a relative newcomer here. By the time it was first spotted in Napa Valley in September 2009, it had severely damaged an entire vineyard. Since then, surrounding counties have reported sightings, too. Experts say the pest came here from Europe via Chile, possibly on fruit or vineyard equipment. It assumes the color of whatever it eats, so it is difficult to spot. It lays its eggs in grapevine flowers and leaf buds. For control, growers are relying on sticky pheromone traps to lure male moths and prevent them from mating. Some are removing host plants, such as crape myrtle, photinia, pittosporum and oleander. The moths also feed on olives, blackberries, cherries, nectarines and pomegranates.

If you have a grapevine and don’t use the grapes, remove all the flowers and developing fruit. Put them in your yard-waste bin and close the lid.

“We are doing all we can, working with our state and federal partners, to implement a plan to combat this pest in Napa County,” says commissioner Whitmer.  He likes to quote T. S.  Eliot: “It is not necessarily those lands which are the most fertile or most favored in climate that seem to me the happiest, but those in which a long stroke of adaptation between man and his environment has brought out the best qualities of both.”

Garden Tour: Save Sunday, May 15, for “Down the Garden Path,” the Napa County Master Gardeners’ garden tour. The tour will showcase seven unique upvalley gardens owned and maintained by local Master Gardeners. For tickets and more information, visit   http://cenapa.ucdavis.edu.

 

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