Welcome to the October lesson of Kitchen Garden School at Cornell Farm! While we may be winding down for the year, that doesn't mean there isn't anything to be done in our gardens for the remainder of fall and winter. Our lead kitchen gardener, Cynthia DuVal, has tips for fall garden cleanup, soil amendment, and planting select crops — or cover crops — that will overwinter happily in our gardens.
Cleaning Up & Transitioning the Garden
This month, the rains have begun to pick up again in our corner of the Pacific Northwest, signaling the end of the primary growing season. While we may have a few sunny days still in the forecast, it's unlikely to be enough to ripen any immature fruits developing on our warm season crops, so you're probably best to cut your losses and go ahead and harvest what you can and begin the cleanup process.
This is especially true for tomatoes, which can easily split after periods of heavy rainfall. But take heart: Any tomatoes that are beginning to show color will continue to ripen on your counter if you bring them in now. And, of course, you can always make fried green tomatoes for the rest! (If you can't bear the thought of picking them young, we've heard of people digging up entire tomato plants and hanging them upside-down in a garage or shed so that the fruits continue to ripen on the vines. It might be worth a try, but we can't say we've done it ourselves.)
Most kitchen garden plants are annuals or tender perennials that should be removed from your garden beds as they begin to die back. If you're fortunate enough to have a greenhouse, you might consider potting up your peppers to overwinter them in a place more favorable to their continued growth. When treated this way, peppers can do remarkably well for multiple years. This year, Cynthia is giving this a try with her pepper plants. You can see the roots of one of her pepper plants on the right in the image below, next to those of an eggplant pulled from the same bed. Roots like these are why it's a good idea to water deeply!
Not only does a bit of fall cleanup keep things tidy and clear the way for any fall or winter succession plantings down the line, but removing and discarding these plants helps to prevent the spread of diseases from year to year. While composting is a great way to recycle the organic matter in your garden, it's best to leave a few things off your compost heap. Tomatoes and potatoes can carry a variety of fungal diseases that may survive the home composting process, so it's best to simply discard them at the end of the season. In general, it doesn't hurt to be ruthless when deciding whether to discard — rather than compost — diseased plant material.
Fall Planting
October is perfect for planting many perennial herbs and other plants that will overwinter in our kitchen gardens. In fact, it is ideal for planting fruiting trees and shrubs so that they can establish roots before heading into the winter. Bulbs like garlic can also go in the ground from late September through November to provide a bountiful harvest in the year to come. In the video below, Cynthia demonstrates planting some of our favorite bulbous plants in Cornell Farm's display beds, and how she amends the soil in preparation.
Garlic, Shallots, and Onions
There are two main classifications of garlic varieties: Softneck and hardneck. As the name would suggest, the more common softneck garlic varieties feature a soft and flexible "neck" or stem, and are grown for their abundance of cloves and long shelf life. On the other hand, hardneck garlic, as one might suspect, has a much woodier stem. And while they don't produce as many cloves, they more than make up for this in terms of their size and taste. In this month's video, Cynthia plants the hardneck varieties Musik and Chesnok Red, and a softneck variety known as Inchelium Red — plus Holland Red shallots and sweet yellow onions. When planting the garlic and shallots, you should separate each head into individual cloves, and plant them with the pointed end facing up, about 3-4 inches down. (Onions don't need to be separated, but should be planted in the same orientation.)
Fall is the time for planting all three of these crops because it gives them to establish strong root systems before winter so that they can hit the ground running with growth as soon as temperatures begin warm. Onions will be ready to harvest as early as late spring, and garlic and shallots in the summer. And for an extra harvest, Cynthia is interplanting this bulb crop with two successions of lettuce in the form of starts and seeds, for fall and winter harvest respectively.
Cover Crops
In any kitchen garden beds where you don't plan to overwinter any cool-season crops, you might consider planting a cover crop to protect and feed your soil during the "off" season. Cover crops act as a "living mulch" that helps not only to keep weeds at bay, but to hold the soil in place through winter winds and rains. And when they die back or are cut down and incorporated into the soil, they provide organic matter that improves soil structure and nutrition. Some cover crops — in particular legumes — can even fix nitrogen from the air, providing added nutrients.
There are a variety of both annual and perennial cover crops that can be sown in our climate, but here are a few common ones:
- Buckwheat is particularly good at mining the soil for phosphorus, which kitchen garden plants need to flower and fruit.
- Fava Beans are great for fall cover cropping, as these nitrogen-fixers will keep growing in temperatures down to 35°F.
- Winter Rye has fibrous root systems that are great for to breaking up heavy, clay-rich soils, which is especially helpful if you plan to plant root vegetables down the line.
If you don't choose to plant a cover crop, you might consider adding fresh compost or leaves as a mulch in your edible beds this time of year, which will act to both add nutrients to your soil and suppress weed growth!
Looking Ahead
While there isn't as much going on in the garden during the late fall and into winter, determined gardeners can keep many plants going through the cold months. We're already enjoying a few peas here in our "second spring," and are looking forward to harvesting lettuce and broccoli before frost. If you're looking to extend your season even further, hoop tunnels, cloches, and freeze cloth can be used to keep your plants 3-5 degrees warmer than the outside temperature. (Freeze cloth is also useful for protecting certain plants like citrus during an exceptionally cold spell.)
Other Activities & Resources
Check out a few of the tasks you can undertake in the kitchen garden right now, along with the following "recommended reading."
- Reading the October, November, and December chapter of The Maritime Pacific Northwest Gardening Guide from Tilth Alliance (pages 92-107 in the second edition) will not only get you caught up on what there is to do in the garden this month, but what can be done in the months ahead.
- If you haven't been keeping a garden journal, there's no time like the present! While the harvest is fresh in your memory, even a few quick notes about what worked well and what you would like to tweak in the future are sure to come in handy.
- Consider starting a compost heap if you don't already have one going! With leaves beginning to fall and garden cleanup going on, this is a time of year when we can add a lot of organic matter to our compost bins.
- If you have excess produce from your garden, consider giving it to neighbors or your local food bank!
- If you are gifted a citrus tree for the holidays, be sure to check out our guide to growing citrus to ensure the survival and health of your tree.
October Planting
Although we are winding things down with the approach of fall, there are still many plants that can go in the ground in fall.
- Fall is the ideal time to add fruit trees and shrubs to your landscape, as cooler temperatures and rains help these plants get established before their growth slows in the winter. We have a great selection at the Nursery this time of year!
- As discussed in this month's lesson, September to November is the ideal time to plant out garlic, shallots, and onions for harvest next year.
- Many brassicas (broccoli, cabbage, kale, etc.) and leafy greens will overwinter as young plants, which can be harvested sparingly through the winter, or left until spring for an early harvest. You generally want these crops to be only a couple of inches high before heading into frost conditions; too big, and they may get knocked back. As an extra incentive, the taste of many of these crops is often sweeter after going through the cold of winter, as their plant tissues have stored sugars that were used to help keep them from freezing!
Connect With Us
If you have questions about edible gardening or would like help selecting plants, our knowledgeable team is always happy to assist you in the Kitchen Garden Greenhouse. Cynthia often gives informal tours of our display beds, so feel free to stop by for a quick walk-around! For help from afar, you can reach out to Cynthia and our Kitchen Garden team directly at edibles@cornellfarms.com.
We are also excited to share that, for those wanting more individualized assistance with their kitchen gardens, Cynthia is also available for personalized 90-minute Garden Coaching Sessions held in your very own garden.