A Change in Pace in the Summer Food Garden
Leading up to and into the spring/summer planting season, we were busy improving the soil, increasing irrigation (hopefully inspecting or installing a drip system), pulling the summer weeds that replaced the winter weeds, transitioning our garden from spring to summer crops, mulching and taking various actions to fight the onslaught of vertebrate and insect pests looking for something tasty to eat. We were "human doings." Now that our summer crops have matured and are producing, we can take a little respite...sitting in the shade of the garden and sipping a cool drink. We get to become "human beings" again. Enjoy the respite, but don't relax too much. We still have four major jobs in the August kitchen garden (and into our usually hot Sonoma County September): 1) harvesting crops at their peak, 2) replacing moisture lost to increased evapotranspiration (ET), 3) watching out for and preventing crop damage, especially damage caused by hot temperatures and intense sunlight and 4) planning the transition to our fall and winter food garden.
Consuming garden-fresh produce is the reward for food gardening. In August we have an abundance of fruits and vegetables to share with friends and family. But, don't waste the investment of time, effort and money that went into the food garden by failing to harvest at the right moment for each crop. For easy reference, we gleaned the harvest advice in the California Master Gardener Handbook and put it into one easy-to-reference harvesting chart.
When the weather heats up and you reach for another beverage, remember that your crops are feeling about the same way. On average, Sonoma County soil loses about 1 inch of water per week during the summer. We've set our drip or hand-watering schedule based on this average. But, remember that it's just an average. When weather is in the 90's for a stretch of time and spikes above 100, you'll need to supplement that watering schedule. Always check the soil moisture before irrigating...you have a handy tool with you all the time: your finger. For more info about drip irrigation systems and hand watering, see our article "Conserve Water" as well as our Food Gardening with Less Water page.
Another bi-product of hot weather and intense sunlight is abiotic damage to our plants. This includes crop sunburn, blossom end rot, solar yellowing, green shoulders, fruit cracking and leaf roll. Summer food gardeners are most concerned about these conditions in tomatoes, but other warm-weather crops also can be affected. Shade cloth, even watering, mulching, avoiding high Nitrogen fertilizers and the like can mitigate many of these symptoms. Read more about and see photos of the common tomato problems in the UC Master Gardener Program Blog. Also, be on the lookout for some common warm weather pests such as tomato hornworms--a good snip of the pruners takes care of them. Don't forget the weeds that can harbor pests such as the tomato russet mite waiting to attack from field bindweed. The UC Integrated Pest Management page is a gold mine of information and advice.
And, while you are sipping your cool drink, pull out your planting diary from last year along with the seed catalogs. Plan your fall and winter food garden. Master Gardener Janet Barocco tells us why a cool weather vegetable garden is cool in her article Cool Season Vegetable Gardening. If you've never had a fall garden, check out article below to find out where and when the Food Gardening Specialist group will be providing free workshops.
In the Garden
It's Getting Hot, Hot, Hot! Food Gardening With Less Water
During our hot, dry Sonoma County summer food gardeners need 1) to provide enough water to their crops in order to replace the amount lost to surface evaporation and plant transpiration (the "ET Rate") AND 2) to do so in a manner that conserves water. On average, our soils lose about 2 inches of water per week per cubic foot during a typical summer. This cubic foot is the area in which most our crops' active root zones reside. That means for every square foot of garden surface, we have to replace about 2/3 gallon of water per week. However, we don't do it all at once. Instead, we divide that amount of water into 3 to 7 applications per week in order to provide more consistent moisture for maximum crop health and production. The most efficient way to deliver water to our crops is through drip irrigation that targets each plant. Plus, there are other actions we can take that reduce ET such as adding compost, applying mulch and using shade cloth. You can learn more by viewing our Food Gardening with Less Water page. This page provides a variety of helpful documents including how to install a drip system (along with a shopping list) as well as a form to determine how long you need to run your drip system. While on this page, check out the video made by our Master Gardener Food Gardening Specialists. If you are unable to use drip (e.g., your water quality clogs emitters or you belong to a community garden that doesn't have drip irrigation), see our Conserve Water article that is part of a series on sustainable food gardening, and which includes a method to determine how long to hand water.
Save the Dates for Free Fall and Winter Food Gardening Workshops
Don't miss planting a fall and winter garden. August is not too early to start in Sonoma County! And, if you don't plant a fall/winter garden, learn how to put your garden to bed as well as strategies to improve your soil over the winter. Save the following dates (look for descriptions on the calendar this summer; Saturday workshops are from 10:30 a.m. to 12:30 p.m. unless otherwise noted):
- August 4, Fall into Food Gardening, Sebastopol Regional Library
- August 25, Fall Food Gardening, Harvest for the Hungry Garden, Santa Rosa
- September 8, The Transitional Fall/Winter Food Garden, Windsor Community Garden
- September 15, 10-11:30 a.m., Fall/Winter Food Gardening, Bayer Farm Community Garden, Santa Rosa.
Plus, the Food Gardening Specialists and Kendall Jackson Winery will offer a special for-fee event on Sunday, September 30 in the Kendall Jackson Winery food garden. Stay tuned for more details about this fun and informative day. Designated funds from this event will support the all-volunteer Sonoma County Master Gardener program, allowing us to continue to provide free science-based, sustainable gardening education and consultation to county home and community gardeners.
Low-Water Herb Garden
Master Gardener Jason Robinson shares which herbs you can grow to spice up your meals without expending an inordinate amount of water. Not only are they perennial plants in Sonoma County, these herbs also have the advantage of deterring critters like deer with their aroma and/or leaf texture. If you buy nursery starts, protect them for a few weeks until their delicious saltiness (from the liquid fertilizers that nurseries tend to use) dissipates. Regular water will be required until the the plants are established. Read more.
Food Garden Specialists
Food Garden Specialists (FGS) are volunteers in the UC Master Gardener Program of Sonoma County. They have a passion for and extra training in sustainable food gardening. In addition to offering food gardening workshops, they provide free advice and consultation services to community gardens throughout Sonoma County. Read more.
Food Garden Tips
August Food Garden Tasks and Tips
For what to grow this month, click here.
- Start germinating cool-season veggies. Sow root crops such as beets, carrots and parsnips directly in the ground. Pay close attention to days of maturity. Timing of planting is very important. Fall crops must mature and produce before the growing season ends; winter crops must develop vegetable structure before winter so that they won’t bolt in spring without producing. Bulb onion seed sown now will produce green onions throughout the winter and bulb onions in the spring.
- Set out fall/winter vegetable transplants later in the afternoon and use a row cover for a couple weeks to protect tender seedlings from the sun. Mulch will help with water retention and weed suppression now and protect against cooler weather in October and November. Mulch should not touch the plant stems. Stagger plantings of leafy greens and other favorite cool weather crops that can be harvested before mid-November (average frost date for Sonoma County) and root crops that will survive the winter for a continued harvest.
- Many fall crops are not the most water-wise, so, consider these strategies: Instead of direct-seeding in the hot, dry month of August, you may want to transplant when the weather cools (and, hopefully, fall rains arrive). Check for varieties with a shorter days-to-maturity that can reach maturity before the average first frost date (mid-November in Sonoma County). This will allow you to plant later—hopefully, not in the heat of summer. Given the uncertainties of climate, choose “drought-resistant” or “drought-tolerant” varieties if they are available. Note that this terminology reflects the established plant characteristics; all seed requires water to germinate. Also, see the Food Gardening with Less Water page on the SCMG website.
- Remove finished summer crops by cutting plants just below the soil line to leave the roots to decompose in place. Before planting fall/winter crops, pep up your garden soil by adding one to two inches of properly composted organic matter. No need to dig it in—just add it to the top of the soil and plant into it. Other options include 3-4-3 dried chicken manure pellets OR a complete organic fertilizer (always follow the fertilizer manufacturers’ instructions).
- As always: Weed. Do not let weeds go to seed! They are competing for water and light.
- Pinch back flower heads and spikes on your herbs to maintain the best leaf taste, to encourage new growth, and to discourage bolting in August heat.
- If you split your citrus fertilization into three applications this year, make your last application this month. For mature citrus trees use 1 lb of urea or 6-10 lbs of steer manure (reduce for smaller trees). If spider mites are present, use insecticidal soap or a stream of water to wash them off. New mite generations develop rapidly and may require repeated treatments.
- Applying a few drops of mineral oil with a medicine dropper to corn silks just inside each ear 3 to 5 days after silks first appear may be effective in preventing damage from corn earworm.
- Remember to look at your planting calendar, annotated with days to maturity, so that you harvest your crops at their peak of flavor.
- If there is disease in your orchard or food garden, wipe or dip your pruners with alcohol (ethanol or isopropyl) or spray with a disinfectant spray after every cut so that you do not spread the infection.
- Fight critters with critters – build a bat or owl house. Bats eat moths like the ones that lay eggs on vegetables, eggs that turn into hungry caterpillars. Voles are a tasty treat for owls.
- Inspect crops regularly throughout their growing season for early problem diagnosis and resolution. Refer to University of California’s Integrated Pest Management (IPM) site. Is the summer garden infested? An insecticidal soap spray or a horticultural oil will smother many soft-bodied pests including aphids, mites, thrips and whiteflies without harming many beneficial insects and bees. If you could not control corn earworm (AKA tomato fruit worm) this summer, remove or disc stalks to reduce overwintering populations and prevent migration to neighboring crops. If the veins in your tomato leaves turn purple, your soil is deficient in Phosphorus; this is easily treated with a foliar spray of Epsom salts and/or adding bone meal to the soil.
- Know what pest you are fighting so that you can select effective pest management strategies. Check out University of California’s natural enemies gallery.
- Good cultural practices (i.e., the correct location, light, water, pruning, fertilizer, planting date) contribute to healthy plants. Sanitation is an important aspect of disease prevention: clear garden debris.