Transitioning to the Fall and Winter Food Garden
There is some very important information that translates into having a successful fall, winter and/or early spring harvest. All of this information is used now as we transition our summer garden to fall.
1. Hardy vs. Half-Hardy Cool Weather Vegetables. Refer to page two of the Year-Round Food Gardening in Sonoma County publication to see what veggies can be planted in September and October. Not all of these veggies withstand the same degree of cold weather. Half-hardy crops (such as lettuce and cauliflower) can withstand a limited or light frost whereas hardy crops typically can tolerate a heavy frost (24-28 degrees F). If you want to harvest over the winter and/or early next spring, include hardy crops such as broccoli, Brussels sprouts, cabbage, collards, corn salad, garlic, kale, leeks, bunching onions, radishes, Daikon radishes and spinach. Also, note that most root crops can be "stored" in the ground as long as the ground doesn't freeze (for example, turnips and beets--unless you are growing them for their greens).
2. Average First Frost Date. If you've lived in your current location for some time, you probably can estimate the first frost date based on past experience. But, if you're not sure, NOAA has you covered. They produce averages based on the past 30 years of collated data (updated every 10 years) for every weather station. We've made it a little easier to find this info by extracting the data for Sonoma County weather stations (see First and Last Frost Dates for dates based on different risk percentages in your area). Bring half-hardy veggies to maturity before this date and hardy veggies to at least near maturity by this date. As they say in banking, past performance is not an indicator of future earnings, but this is the best information we have for planning purposes.
3. Ten Hour of Sunlight. At Sonoma County's latitude, we have less than 10 hours of sunlight from November 18 to January 23. During this time, crops imperceptibly grow or stop growing. If your area's first average frost date falls after November 18, use November 18 when determining when to bring a crop to maturity. Some hardy crops, if brought to a reasonable size by November 18, can be harvested throughout the winter and/or will begin growing again after January 23 for an early spring harvest.
4. Days to Maturity. Every crop (and every variety) has a "days to maturity"--the days from when the seed or transplant is put in the ground to the date the first edible leaf or fruit matures. Usually you can find this information on the seed packet. If not on the packet, you will find it easily on the Internet. The date you plant and how you harvest (e.g., harvesting baby lettuce leaves) will affect your variety selection.
Now that you are armed with essential information and using the "days to maturity" for the varieties you've selected, count back from your area's last average frost date (or November 18, if earlier). Now add two weeks--remember that maturing will slow as the days get shorter and cooler. The date you calculate using this process is the last day to get your crops in the ground if you intend to harvest them before frost arrives (and, for a decently long harvest of half-hardy crops, you'll want them to mature a bit sooner). If you find that you're too late to plant a particular variety, just select another variety with a shorter days to maturity. You have a little wiggle room (but not much) if you intend to bring hardy crops to near maturity (for an early spring harvest) by that date. Your cool weather crops will enjoy starting in the warm soil and maturing in the cooler weather. And, if you are the industrious type, you can use season extenders (cloches, frost cloth, plastic tunnels, etc.) to protect the half-hardy crops when frost is extended or heavy. Enjoy your fall and winter harvest!
In the Garden
Etch Your Pumpkins
While your pumpkins are still growing and the shells have not completely hardened, you can etch your pumpkins with a sharp object. Young children will be thrilled to receive a pumpkin with their name on it. Be sure NOT to pierce the shell to the internal fruit. The shell will "heal" itself by forming scar tissue...and showing off your etching.
Fall and Winter Food Gardening
Don't miss planting a fall and winter garden. There are many cool weather veggies that can be planted in September in Sonoma County.
Plus, the Food Gardening Specialists and Kendall Jackson Winery will offer a special for-fee Harvest Celebration on Sunday, September 30 in the Kendall Jackson Winery food garden. This fun and informative day includes Master Gardener food gardening workshops, food samplings from local chefs, wine blending and tasting, truffle hunting, painting sessions, mozzarella stretching, barrel making and more. Check KJ's website for details and tickets. Funds from this event 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.
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.
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
September Food Garden Tasks and Tips
For what to grow this month, click here.
- Don’t stop weeding…they are still growing and competing with your vegetables for water and light.
- If you did not replenish the food garden soil last month, add two inches of good quality compost on top of the soil now. Why? Compost 1) builds soil structure by creating pores for air and water; 2) improves moisture retention in light soil; 3) improves drainage in heavy soil; 4) feeds microorganisms that provide a symbiotic relationship between the soil and your plants so that plants can use the nutrients; and 5) provides all the nutrients – in combination with the soil – that your plants need. Higher soil nutrition helps plants produce better yields with the same amount of water!
- If September is hot, set out fall/winter vegetable transplants later in the afternoon and use a row cover for a week or two to protect tender seedlings from the sun. If possible, try to time transplanting veggie starts to coincide with the start of a cooler weather cycle, then watch to make sure they have adequate water when the temperatures go up.
- In Sonoma County, the summer food garden is still in high production. If you have an overabundance of squash, pick them when they are very young and tender. If you have more produce than you can use, your neighborhood food bank or a neighborhood gleaning program will be happy to help you out.
- Mulch will help with water retention and weed suppression now and protect against cooler weather in October and November. Use three to four inches depending on the size of the mulch particles. Mulch should not touch the plant stems. Do not cover seed beds with mulch.
- Stagger plantings of leafy greens and other favorite crops that can be harvested before mid-November (the average frost date for Sonoma County).
- Plant hardy crops that will survive the winter for a continued harvest.
- Remove the tips and small fruits of melons and winter squash as they won’t have time to mature. Also, pinch off the last blossoms of tomatoes, eggplant, peppers, and squash to encourage larger fruits.
- Clean up fallen fruit after harvest. Dispose of diseased material.
- Citrus: apply 1/2 pound 5-2-1 organic fertilizer mixed with 1 tablespoon Epson salts per tree, then water well.
- Raspberries: foliar feed with liquid fish fertilizer twice this month.
- If you find snails and slugs in your garden, build a trap using a 12- by 15-inch board raised off the ground by 1-inch runners. As they collect under the board, scrape them off and destroy daily.
- 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.
- 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.