(Author’s note: The following essay was taken from The New England Gardener’s Year by Reeser Manley and Marjorie Peronto (2013, Candent Publishing). The original text has been revised with new variety recommendations.)
Mid to late July is the beginning of the vegetable garden’s second season. In addition to planting seedlings of broccoli and the other brassica crops, including cauliflower and cabbage, this is the month to sow seeds of beets, peas, green onions, lettuce, Swiss chard, and turnips. And it is the time to plant leafy herbs such as basil, dill, and cilantro, fast-growing herbs that will be ready for harvest about a month after sowing the seed. You can harvest the young leaves as needed until the plants are killed by frost; basil is very frost sensitive, but cilantro will tolerate the first light frosts.
Leafy vegetables, such as spinach, Swiss chard, kale, mustard greens, and leaf lettuce are second-season crops that should be harvested before their leaves reach full size. The small leaves are often more tender and tastier than mature ones. These crops can be planted in succession every few weeks as small spaces open up in the garden to provide a steady supply of young leaves.
Remember that many of these second-season plants, including most of the leafy vegetables and turnips, can survive and even improve in flavor after a light frost. Beets, green onions, and peas will survive 28° F, while the hardiest varieties of Brussels sprouts, cabbage, and kale are cold hardy to 20° F.
In general, be sure to incorporate compost or organic fertilizer into the soil before starting any of these fall crops. If you need more seed for these second-season crops, buy it now while garden center racks are still stocked. Many mail-order seed companies are still filling orders as well.
In the following guidelines for planting your late-summer and fall vegetable garden, sowing and planting dates are for USDA Zone 5. Delay by one or two weeks for gardens in Zones 6 and 7, respectively. Subtract one or two weeks for gardens in Zones 4 and 3, respectively.
Cilantro and Dill
In the second week of July, sow seeds of cilantro and dill directly in the garden, taking advantage of spaces that have opened up as summer crops were harvested. By mid-August, you will have plenty of fresh cilantro leaves and tender dill shoots for use in the kitchen.
By mid-July, earlier sowings of these two annual herbs will be flowering. Let a few of these plants go to seed, then either collect the seed for use in the kitchen or allow the plants to self-sow next year’s crop.
Basil plants grown from seeds sown in July, in the garden or in pots, will produce a first cutting by mid-August. Continue cutting through September, but remember that basil is very sensitive to frost, so be sure to get your last cutting of fresh leaves when that first frost of the season is imminent.
Start this crop from seed indoors in the first week of July so that you will have four-week-old transplants for the garden by the first week of August. You should be able to harvest sprouts about 90 days from planting, after they have been kissed by a frost.
Several seed companies, including are offering a new variety of Brussels sprout, “Bitesize”, with small green buttons about half the size of standard sprouts. These super-sweet sprouts hold their baby size for a long time.
Broccoli, Cauliflower, and Cabbage
Seeds of these brassicas should have been planted in June to produce garden transplants for mid-July. If you did not make this sowing, perhaps your local garden center did. When shopping for transplants, be sure to purchase young transplants produced for midsummer planting, not potbound, worn-out leftovers from the spring crop.
Among the broccoli varieties recommended for late season gardens, Territorial Seed Company (www.territorialseed.com is introducing “Hallmark”, a standout in their winter trials. The heads stand up to rain and cold better than other broccoli varieties.
Baker Creek Heirloom Seeds (www.rareseeds.com) carries an heirloom cauliflower, “Purple of Sicily”, with large 2-3 pound heads of brilliant purple that change to green when cooked. In addition to a sweet, refined flavor, this variety is naturally insect resistant.
Successive sowings of lettuce can be started in late July. Sow seeds in vacant spots of the garden as they open up.
This year I want to try “Brown Dutch” lettuce, also sold as “Winter Brown”, a loose-headed variety with large, floppy, blistered outer leaves that are tinged reddish-brown. This variety was a favorite of Thomas Jefferson, the most frequently planted of the approximately seventeen lettuce varieties planted in his kitchen garden at Monticello. Jefferson’s records show that this variety was sown twenty-seven times between 1809 and 1824, primarily in the fall for a winter harvest. You can order seed for this variety from the Thomas Jefferson Foundation (http://www.monticelloshop.org/600460.html).
Because of problems with early bolting of spring-sown spinach, many gardeners in northern New England wait until late July to early August to sow spinach. Late-summer-sown spinach will continue to produce leaves until the plants succumb to freezing temperatures. Recommended varieties for fall sowing include Avon, Indian Summer, Melody, Razzle Dazzle, Olympia, and Tyee.
Summer-sown spinach seedlings will need shading through periods of hot weather and plenty of water. Spinach only needs 30 to 45 days from sowing to harvest, so you can continue sowing through late summer.
Use the “cut and come again” method of harvesting your spinach, removing the older, outer leaves of each plant while allowing the young inner leaves to continue growing for a later harvest. If you need a lot of spinach, cut entire plants about an inch above the crowns; the plants will likely send out a new flush of leaves.
Other Crops for Vacant Spots in the Garden
Seeds of bush beans, carrots, beets, kohlrabi, radish and turnips can all be directly sown starting in mid-July as space becomes available. If you have the garden space and leftover seed, start a fall crop of garden peas with a mid-July sowing. Success varies from year to year, but even a small crop of fresh peas in September is worth the effort.