- Author: Ed Perry
Soil solarization is a simple technique that you can use in your home garden to reduce or eliminate many soil-inhabiting pests. Solarization works by heating up the soil in the presence of moisture to temperatures that are high enough to kill many fungi, nematodes, weeds and weed seeds.
In order to solarize your soil, you must leave a clear plastic tarp on the soil surface for 4 to 6 weeks during the hottest part of the year, which of course is now. Black or colored tarps will not allow the soil to get hot enough, so you must use transparent plastic. Polyethylene plastic 1 mil thick is the most efficient and economical, but you must handle it carefully because it rips and punctures easily.
Before laying the plastic down, clean up all weeds, debris and large clods, then level and prepare the soil as for planting. The closer the tarp to the soil, the hotter the soil becomes. Air pockets caused by clods or debris will decrease the effectiveness of the treatment. A smooth, bare soil surface is best.
You must also wet the soil before covering it with the tarp. The moisture causes organisms to be more sensitive to heat and also allows the heat to penetrate deeper into the soil. It's best to wet the soil thoroughly before laying the tarp.
While some pests may be killed within a few days, 4 to 6 weeks of treatment in full sun during the summer is needed to kill most pests with solarization. The highest soil temperatures will occur when the days are long and hot, and when the sky is clear and there is no wind.
Many disease organisms are effectively controlled with solarization, including the fungi that cause Verticillium wilt, Fusarium wilt and damping off of seedlings. Many annual weeds are also controlled, but perennial weeds such as Bermudagrass, field bindweed, johnsongrass, and yellow nutsedge are suppressed but not completely controlled by the procedure. Nematode populations are also reduced, but the heat may not penetrate deep enough to destroy those below the top foot of soil. Nematodes should be controlled well enough for shallow-rooted crops.
Once the solarization is completed and you've removed the tarp, take care not to disturb the soil very much. Turning the soil can bring up living weed seeds and diseases that were too deep to be destroyed by the heat.
Read the publication Soil Solarization for Gardens & Landscapes for more information.
- Author: Anne E Schellman
Summer is here, and so is the Stanislaus County Fair! Our brand-new University of California Cooperative Extension (UCCE) Master Gardener Program is excited to have a presence at the fair this year, with volunteers who have just graduated this past June.
Come see us in front of the Floriculture building located just inside the fairgrounds near the arch gate off 900 North Broadway. Our table that will showcase a colorful poster all about our program. Come find out who we are and what we do and ask your gardening or pest questions.
Pick up free copies of Quick Tips cards on pests like ants, powdery mildew, cockroaches, and more! We'll also be giving away carrot and California poppy seeds (while supplies last).
Want to be a UCCE Master Gardener in Stanislaus County? We have flyers with all the information you need and will be taking applications next week!
For more information about the fair, visit the Stanislaus County Fair website.
- Author: Ed Perry
Home gardeners often become concerned when their fruit trees begin dropping fruit prematurely. In some cases, fruit drop is nature's way of reducing a heavy fruit load. In other cases, premature fruit drop may be caused by pests and diseases, adverse weather conditions or poor cultural practices.
Apples may have a couple of periods when fruit drop occurs. The first is often after the flower petals fall off and may last two to three weeks. The very small dropping fruits are the ones that were not pollinated, so will not develop further. Many fruit species need to be pollinated by bees. Lack of pollination may be the result of cold or wet weather during the bloom period, or by a lack of honey bees. Also, if there is freezing weather just before the flower buds open, more fruit drop may occur.
Other adverse weather conditions may also contribute to fruit drop. For example, persimmons may drop if the weather turns suddenly hot in spring, just as the small fruits begin to develop. Trees not receiving adequate irrigation water would be more prone to dropping fruit.
Pests and diseases may contribute to the problem of premature fruit drop. Cool wet weather during the bloom period of walnuts often results in infections of walnut blight, a bacterial disease that damages catkins, leaves, and newly-pollinated nuts. Infected nuts may drop prematurely. Premature ripening and fruit drop often occurs in apples and pears that are infested with codling moth larvae.
In apples and pears, a second drop occurs once the fruits are about the size of marbles, usually in May or June. This is commonly referred to as “June drop.” Fruit drop at this time of year is thought to occur as a result of competition between fruits for available resources.
Some fruit tree species, such as plums, may experience a mid-summer fruit drop. Proper fruit thinning can help to prevent this. How much to thin depends upon the tree species. With peaches and nectarines, it's important to make room on the branches for each fruit to grow to 2 ½ to 3 inches in diameter. Thin by pulling off ¾ to 1-inch long fruit in April and May, leaving one fruit every 6 inches. This results in more fruit on the ground than on the tree, but it's important to produce large, flavorful fruit and to minimize limb breakage.
Thin apricots when the fruit is about ¾ inch in diameter, leaving 1 apricot every 3 inches. Thin plums when the fruit is ¾-inch-long, leaving 1 plum every 4 to 6 inches. Thin apples after the usual May or June drop. Leave 1 apple every 6 inches or allow only 1 apple to remain per spur. Asian pears should be thinned to leave only 1 fruit per spur.
When mature fruit begins to drop, it's a sign that the fruit is ready for harvest.
Ed Perry is the emeritus Environmental Horticultural Advisor for University of California Cooperative Extension (UCCE) in Stanislaus County.
- Author: Anne E Schellman
On Thursday, February 7, the University of California Cooperative Extension (UCCE) Stanislaus County Master Gardeners held their very first class. The topic was spring vegetable gardening. UCCE Master Gardener Royce Rhoads discussed how to tell if your seeds are still “good,” what supplies are needed to start vegetable seeds indoors, and what vegetable seeds to plant outdoors.
We were excited to have 64 people attend our first event! Feedback from participants included:
- Thanks for the opportunity to attend and learn some basics.
- Appreciated the clear and concise information.
- This program is off to a great start and will be a real asset to our community!
If you couldn't make the class, you can download our free Vegetable Gardening Guide. It has step-by-step information on preparing garden beds, proper irrigation, dealing with pests and diseases, and a guide to which vegetable crops you can grow in our area and tips for growing them. You can also contact the UCCE Master Gardeners with your questions by calling (209) 525-6800 or sending an email to ucmgstanislaus@ucanr.edu.
Never miss a class! Stay in touch by subscribing to our newsletter blog, The Stanislaus Sprout. Look for the word "subscribe" on the top right-hand corner of the page. Add your name to receive gardening and pest management tips, as well as announcements for future classes and workshops.
- Author: Anne E Schellman
Pests need food, water, and shelter to live. Unfortunately, some of us unknowingly attract and even invite pests to live in and around our homes!
Insect and animal pests can pass through small spaces. For example, mice can get through a hole the width of a pencil, and cockroaches can flatten themselves and squeeze through cracks. Here are some circumstances that attract pests, allow them access, and provide them with food, water, and shelter:
Pest Attractors and Supporters
- Pet food and water bowls (indoors and outside)
- Bird feeders
- Leaking water spigots
- Open food packages in your kitchen
- Hedges and shrubs near doors or windows
Entry Points
- Holes in windows and screen doors
- Cracks in the foundation of your house
- Holes in the roof or attic
- Crevices around pipes indoors (bathrooms, laundry area, kitchens) and outside
Use IPM to Manage Pests
Use integrated pest management or IPM to help you pest proof your home. First, walk in and around your home to inspect for the above pest attractors, supporters, and entry points. Once you find a pest, for help with identification contact the UCCE Master Gardeners of Stanislaus County at (209) 525-6800.
If you can't personally inspect your home or don't have time, you can call a pest control company and ask them to do it for you. This is helpful for hard to access places like basements and attics.
For Quick Tips on common pests and their management and prevention from the UC IPM website, click below.
Other Helpful Links
What is IPM?
UC IPM Website
Pest Notes Library
Stay in touch! Follow us on Facebook or Twitter @UCMGStanislaus