Don't put down those garden gloves for the year just yet! Believe it or not, October happens to be one of the most fruitful times of year to plant spring-blooming bulbs, hardy vegetables, and shrubs of many varieties.
Mid-August to mid-October is an ideal time of year to plant new trees, though, that time frame can be stretched into November and December. To be 100% sure, measure soil temperature early in the morning for a few, consecutive days. If your soil is consistently 50° F or higher, you're good to plant.
Leafy greens and Brassicas: Lettuces, spinach, and Swiss chard can be planted from seed or from transplant this month. Plant members of the Brassica family, including broccoli, cabbage, Brussels sprouts, kale, kohlrabi, and cauliflower, from transplant. Kale can also be planted from seed in October.
From early fall through most of November is one of the best times of year to plant spring-blooming bulbs, cool-season annuals and vegetables, as well as many trees, shrubs, and perennials.
Although each plant's needs may vary and some will be more winter-hardy than others, in general about a month before the last fall frost is sufficient in giving the plant enough time to establish itself and take root.
Spring-blooming perennials, especially in the bare root form, are best planted early in the fall. Planting in the fall while the soil is still warm will give the roots enough time establish properly. This allows the plants to emerge from well established roots, with a stronger start, the following spring.
Fall is a great time to plant perennial herbs, which come back year after year and thrive in either pots or planting beds. Plant herbs such as thyme, oregano, mint, and sage any time from summer to mid fall, and you'll be able to harvest now and up until a hard freeze.
The most vigorous growth of plants will be in the summer when the sun is up and out the longest. During winter, the sun is neither as high in the sky, nor in the sky for as long as it is in the summer. For your plants, that means less light. For some plants, this may trigger dormancy.
You can sow seeds for winter vegetable crops, like salad greens, radishes, carrots, onions, Swiss chard, English peas and kale. Look for transplants of other cool-season vegetables, including Brussels sprouts, broccoli and cauliflower. Herb transplants also appear in garden centers during winter.
Fall is Good for Root Growth
Warm soil temperatures encourage root growth – more so than in the spring when the soil is still warming up. Plus, with the shorter days and cooler air temperatures, plants spend less energy on growing foliage and flowers and more on building a strong root system in preparation for winter.
Similarly to pansies, chrysanthemums or mums are best planted in October from an established plant rather than from seed. Keep in mind that these beautiful blooms can't typically survive winter weather conditions, but you can keep your mum plants living longer if you bring them indoors.
September/October is the ideal time to take cuttings from your favourite strains of tender perennials to increase your stock for next spring or to make sure they live on if the parent plants do not survive the winter.
Some of the best vegetables to plant in December include kale, microgreens, radishes, and asparagus. You may also get away with planting scallions or green onions outdoors, and an indoor herb garden will always thrive no matter the outside temperatures!
In general, aim to finish your fall planting about 6 weeks before your first expected frost date (8 weeks for evergreens). In Zones 3 and 4, you would count back from the latter half of September.
To support plants through this season of transition, make sure they get adequate water until the ground freezes. This is especially important if the summer season has been hot and dry, and for newly planted trees, shrubs and perennials. In fall, plants do not need as much water as they may have needed in summer.
Brussels sprouts, broccoli, cauliflower and cabbage are brassicas (also called Cruciferae) and the plants in this species are wonderful for the fall/winter garden. In fact, you can continue to harvest Brussels sprouts even after a snow. Broccoli, cauliflower and cabbage are tolerant to about 26°F.
Most plants slow down their growth and production in temperatures above 90 degrees. Tomatoes, for example, which are a warm season crop to begin with, basically stop growing or producing leaves, stems and tomatoes around 90-95 degrees.
Sugars fuel plant growth, so the more light a plant is exposed to, the more energy it will create and the faster it will grow.
“For trees, shrubs and perennials fall is a great time to plant,” said Weston Miller, Oregon State University Extension Service horticulturist. “If you plant mid-September through mid-November, the soil is warm and gives plants a long time to establish.
Planting in fall allows these plants to establish root systems that they can then bulk up over the winter. Also, in fall, there's usually more rain– which means less maintenance for you.