Spring is here and if you are like us, you can't wait to get outside and see how your plants and garden are doing! As usual, UC IPM has useful tips for the month of April to prevent pests in the garden and landscape. To see more tips specific to your region, visit the Seasonal Landscape IPM Checklist on the UC IPM website. Here are some general tips to get you started:
- Cover fruit trees with netting to exclude birds and other vertebrate pests.
- Aphids are out already so look for them and their natural enemies such as predaceous bugs like lacewings, lady beetles, and syrphid flies. On sturdy plants, spray aphids off with a strong stream of water or apply insecticidal oils or insecticidal soaps to kill them.
- Manage ants. Plants infested with honeydew producing insects like aphids, whiteflies, and mealybugs may attract ants who take that honeydew back to the nest to feed the colony. Manage ants around landscape and building foundations using insecticide baits and trunk barriers.
- Whitewash tree trunks to deter borers and prevent sunburn. Apply to young trees or older bark on susceptible trees newly exposed to sunlight.
- Look for signs of clearwing moths boring in ash, birch, pine, poplar, and willow.
- Check for signs of powdery mildew on apple, crape myrtle, grape, rose, and stone fruits. Take preventative measures, like pruning, to provide better air circulation between plants.
- Watch for yellowjackets and other wasps building nests in undesirable locations. Knock down newly started nests and use lure or water traps to control populations.
- Prevent mosquitoes by eliminating standing water in gutters, drain pipes, flowerpots, etc. Place Bt “dunks” (Bacillus thuringiensis subspecies israelensis) in birdbaths and ponds to selectively kill mosquito larvae.
- Adjust watering practices as rainfall decreases. Check irrigation systems for leaks and broken emitters and perform maintenance as needed. Consider upgrading the irrigation system to improve its water efficiency.
- Monitor stone fruit trees for pests such as aphids, borers, brown rot, caterpillars, powdery mildew, and scale insects.
Don't see your county on the checklist or want to provide feedback? Let us know!
IPM is a science-based, environmentally sound strategy that farmers, professionals, and residents can use to help prevent or control pests and their damage while at the same time protecting people, bees, beneficials, pets and the planet.
Are you already using IPM?
IPM uses a combination of methods including:
- biological control -- 'good bugs' or beneficial organisms like spiders or parasites that eat or prey on other bugs;
- physical control -- blocking the pest from getting to a plant or in your house. Squishing a pest. Pulling weeds out by hand.
- cultural control -- changing the conditions favoring the pest such as reducing wet areas or fertilizing less
- chemical control -- using a pesticide that controls the pest but is less toxic to other organisms and the environment. Pesticides are considered only when other methods have not been successful.
What are some IPM examples?
Pests such as ants, flies, cockroaches and mice. Prevent them from entering your home by sealing up cracks and crevices, using weather stripping on doors and windows, and repairing and replacing screens.
Monitor outdoor pests so you can decide whether or not take action. Some IPM tactics include spraying aphids off with a forceful stream of water, handpicking caterpillars, snails, and beetle pests, or using row covers to keep pests off your plants.
After reading this article, you may discover that you already practice IPM. To learn more about integrated pest management, visit the UC IPM website What is IPM? or visit the Home, garden turf and landscape pests web page for solutions to common pest problems.
Spring and Summer Vegetables From Your Very Own Garden
By Pat Hitchcock, U.C. Master Gardener of Napa County
When should home gardeners start planting their spring or summer vegetable patches? A recent warm spell with near record-breaking daytime temperatures might have inspired you to consider getting some seeds and plants into the ground.
Your dreams of fresh produce might have been encouraged if you saw all the vegetable seedlings at local nurseries. However, nature is probably not finished with winter yet. Many of those nursery seedlings will not thrive if we have chilly days and nights ahead.
A look at the data can be enlightening. Here are the average monthly high and low temperatures for Napa: February, 62°F and 42°F; March, 67°F and 44°F degrees; and April, 71°F and 45°. But these temperatures are averages, which means that many days have lower lows or higher highs. The record shows that our area has a 90 percent chance of experiencing frost in January, dropping to a 10 percent chance in April. So there is still some chance of frost in the next eight weeks.
What does this mean for vegetables? Annual vegetables belong to several different plant families, but they may be loosely divided into two kinds: cool season and warm season. Cool-season vegetables grow best and produce the highest quality crop when average temperatures are 55°F to 75°F, and they usually tolerate slight frost when mature. In contrast, warm-season vegetables require long, hot days and warm soil to mature. They grow best when average temperatures are 65°F to 95°F, and they are damaged by frost.
March and April are much better for cool-season vegetables than for warm ones. Not only are the temperatures better suited to cool-season produce like broccoli, but they are anathema to warm-season vegetables. If we get frost, these tender plants would need to be protected from exposure that would otherwise kill them. The soil right now is pretty cold as well, and the heat-loving vegetables would not grow much until both soil and air temperatures warm up.
Fortunately, there are a lot of cool-season vegetables and many of them mature in 45 to 70 days. The list includes radishes, beets, carrots, lettuce, kale, spinach, Asian greens, broccoli and cauliflower. So you can plant these cool-season vegetables now and be finished with harvesting in May, in time to plan warm-season veggies. If you have limited garden space, this is one way to maximize production.
In Napa Valley, May is the first month when the average night temperatures hit 50°F, while daytime highs are 76°F on average. Over the summer and into early fall, daytime temperatures climb to the 80s and low 90s and nighttime averages stay in the 50s. These temperatures provide a four- to five- month growing season for the vegetables that need warm soil and warm air to thrive.
The long growing season is helpful because many warm-season plants need a lot of time to mature. In many cases, the part we eat is a fruit, botanically speaking. Melons, tomatoes, winter squashes and pumpkins are all fruits that we eat when ripe. Sweet corn, green beans and summer squash are immature fruits.
May is also the month when soils have warmed enough to plant warm-season produce. Although nurseries sell seedlings of many vegetables for you to transplant, several warm-season crops do better when started from seed planted directly in the ground. These include beans, squashes, cucumbers, melons and pumpkins. The minimum soil temperature needed for these seeds to sprout is 60°F. If you plant the seeds in cold soil, they will not sprout and may rot. In warm soil, the seed will come up readily, rapidly establish a good root system and grow well.
Is it time to plant vegetables? Yes, as long as you choose cool-season plants. Hold off on summer's heat-loving crops until the weather is warmer.
Workshops: U. C. Master Gardeners of Napa County will lead a workshop on “Growing Spring and Summer Vegetables” on Saturday, March 12, from 9:30 a.m. to 11:30 a.m., at the University of California Cooperative Extension office, 1710 Soscol Avenue, Napa. Learn the requirements for success with summer vegetables from seed to starts. Topics include soil types and temperature; when to plant seedlings; how to water, fertilize, harvest and manage pests and diseases. On-line registration (credit card only); Mail-in/Walk-in registration (cash or check only).
The workshop will be repeated on Sunday, March 13, from 2 p.m. to 4 p.m., at the Yountville Community Center, 6516 Washington Street, Yountville. Register for the Yountville workshop at the Parks and Recreation Department at 707-944-8712 or on its web site.
Compost Workshops: on March 5 starting at 9 am and again at 11 am and Worm Composting on March 19 at 9 am. Preregistration is required. Find more information and registration links at our website http://ucanr.edu/ucmgnapa
Master Gardeners are volunteers who help the University of California reach the gardening public with home gardening information. U. C. Master Gardeners of Napa County ( http://ucanr.edu/ucmgnapa/) 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, 707-253-4143, 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? Find us on Facebook under UC Master Gardeners of Napa County.
- Author: Paul McCollum
To all the lovely people,
Here is the garden to-do list for the month of April from the people at Organic Gardening. We have been blessed with some rain this week but we could use a lot more. Summer gardening this year is shaping up to be a challenge and conserving water will be the watchword. One person told me that when she turns on the hot water she saves the cold water until the water warms - she then uses the saved water to feed her potted plants on the patio and elsewhere. Good idea.
Please write with any garden questions.
Paul
April To-Do List for Zone 9
- If slugs and snails are decimating your plants, collect them in the evening, when you're most likely to spot them.
- Plant pumpkins, summer squash, melons, and other vegetables that thrive in heat.
- Every 2 weeks from now until late summer, plant small blocks of bush beans and sweet corn to extend the harvest until frost.
- Thin fruits on fruit trees to increase their size and keep branches from breaking.
- Plant summer bedding plants, such as petunias, lisianthus (Eustoma grandiflorum), wax begonias, and impatiens.
- Sow seeds of nasturtiums, marigolds, portulaca, amaranthus, salvias, vinca (Catharanthus roseus), sunflowers, and zinnias.
- Plant perennials like ornamental alliums, bellflowers (Campanula spp.), daisies, yarrow, daylilies, coreopsis, penstemon, perennial geraniums (Geranium spp.), iris, and statice.
April To-Do List for Zone 10
- Plant perennials so they can settle in before the summer heat arrives; give them plenty of water.
- Plant heat-loving bedding plants, such as vinca (Catharanthus roseus), strawflowers (Helichrysum bracteatum), blanket flowers (Gaillardia spp.), and gazanias.
- Plant roselle (Hibiscus sabdariffa), amaranth, and Malabar spinach (Basella alba) now through August; make sure you give the Malabar spinach some shade and extra water.
- Try some tropical edibles: Buy malanga, gingerroot, and others at the market. Cut them into pieces at least 1⁄2 inch long, and plant. Harvest from October through December.
- Trellis tropical cucurbits (luffa, chayote, Tahitian squash, and so on) on a fence, and reap the rewards this fall.
- Author: Betty Homer
I love traveling along Highway 12 past Suisun City in Solano County, especially days after a good, hard rain which turns the landscape into undulating verdant hills and pastures where livestock graze peacefully. Hidden amongst this bucolic scenery, is a local gem known as the Western Railway Museum in Suisun City, which I discovered by happenstance some years earlier. During April of each year, the Museum hosts a wonderful event where, for a nominal entrance fee, wildflower enthusiasts can take an hour-long, 10-mile trip on one of the Museum’s vintage trains, to catch views of native wildflowers (e.g., consisting primarily of poppies, goldfields, brass buttons, butter and eggs, clover, and sheep’s sorrel) that blanket the hillsides and fields of Solano County. The tours are docent-led and views change weekly, depending upon what is in bloom. My past experience on this tour has been that the train will stop at an appropriate juncture to allow visitors to exit and wander alongside the fields to take photographs and to examine the wildflowers up-close. The window to catch this glorious display of wildflowers is short-lived, as the tours begin on April 3, 2013 and run until April 28, 2013. I recently visited the general vicinity in which these tours take place, and at least as of the posting of this blog entry, there did not seem to be many wildflowers yet on display, but that will quickly change, so consider making your plans now. For additional information about the various tours, times, and ticket prices, please visit (http://www.wrm.org/).