August 23, 20114 found this helpful
Mid to late summer is a great time to plant seeds for a "second season" crop. After harvesting early maturing crops like salad greens, radishes, peas, and spinach, plant a second wave of your favorite cool-season vegetables for a bountiful fall harvest. Even in the coldest zones, there is still plenty of time for varieties to grow and reach maturity before the first frost.
It's All About the Timing
The key to growing second season vegetables for a fall harvest is timing. As the growing season marches on, the days will get shorter, the soil cooler, and the sun's rays less intense. The first step is to determine your average first frost date. Then look at the seed packet for days to maturity and add another 14 days to that number to account for the shortening days. Once you calculate the days to maturity, use that number to calculate back to the seed-starting date. To ensure a harvest before cold weather arrives, select "early" or "fast-maturing" varieties for planting.
Plant These Mid-Summer Crops for a Fall Harvest
- beets: 30 to 60 days to maturity; survives temperatures in the high 20 degrees F
- broccoli: 50 to 70 days to maturity; survives light frost
- Brussels sprouts: 50 to 70 days to maturity; hardiest varieties good to 20 degrees F
- bush beans: 45 to 65 days to maturity; killed by frost
- cabbage: early varieties mature in 50 days; hardiest varieties good to 20 degrees F
- cauliflower: 60 to 80 days to maturity; survives light frost
- cilantro: 60 to 70 days to maturity; survives light frost
- garlic: harvest the following July; winters over in ground
- green onions: 60 to 70 days to maturity; survives high 20s (F)
- kale: 40-65 days to maturity; hardiest varieties good to 20 degrees F
- leaf lettuce: 40 to 60 days to maturity; survives light frost
- mustard greens: 30 to 40 days to maturity; survives light frost
- radishes: 30 to 60 days to maturity; dig until soil freezes
- spinach: 35 to 45 days to maturity; survives light frost; may overwinter
- Swiss chard: 40 to 60 days to maturity; survives light frost.
- turnips: 50 to 60 days to maturity; survives light frost
Don't forget about the flowers! Lots of annual and perennial flowers thrive in cool weather and can be sown mid-summer for fall blooms. Try annuals like alyssum, candytuft, calendula, stock, and sweet peas; or perennials like bee balm, toad lily, red-hot poker, or evening primrose.
Preparing the Soil
Before sowing second season crops, turn over the soil and mix in some balanced fertilizer to replace what earlier plants have used up. Leftover plant debris like stems or roots from the first planting can cause problems in seed germination, so make sure to remove this material as completely as possible.
Mid-summer heat can be stressful to seedlings and transplants normally grown during the cooler, wet weather of spring. Keep the soil moist as your seeds are germinating and protect young seedlings from the hot afternoon sun. Salad crops, which prefer cooler soil, can be started indoors and transplanted outdoors as soon as soil temperatures start to cool down a bit. When the weather turns cold, extend your plants' season by growing crops under row covers and cold frames.
Late summer and early fall is the perfect time to squeeze a second season of vegetables out of your garden. For crops like corn, the warm days and cool nights of fall concentrate their sugars, which acts to enhance their flavor. For crops like spinach and lettuce, the cool weather prevents them from bolting prematurely and turning bitter. Depending on how long it takes your crop to mature and which growing zone you live in, there is still plenty of time to put in a second crop.
Preparing Soil for a Second Season
You don't need a designated vegetable garden to plant cool weather crops. Window boxes, empty containers or an empty space formerly taken up by this year's annuals will all work fine. To prepare soil for planting, clear away old plant debris and work some compost into the top few inches of the soil. If necessary, moisten the soil thoroughly a few days before planting to make it easier to work.
Although temperatures are starting to cool, this time of the year soil temperatures are higher and the moisture level in the soil is lower. In warmer zones, daytime heat can turn topsoil into a hard crust and high temperatures can prevent seeds from germinating. Seeds will need to be planted as much as two times deeper than normal to compensate for these "summer-like" conditions. If necessary, use row covers to help keep the soil cool and moist or sow your seeds in the shade of taller plants.
Cooler Weather = Slower Growth
Shorter days and cooler temperatures slow down plant metabolic processes, so expect cool weather crops to take longer than normal to reach maturity. To figure out what to plant, read the back of your seed packets to find out how many days are needed to reach maturity. Now add another 2 weeks onto the projected number of days needed in order to make up for the reduced amount of available sunlight and the lower nighttime temperatures. For example, if radishes normally take 35-40 days, expect them to take 49-64 days. If you know your average first frost date, take a calendar and count backwards the number of days it takes your crop to mature. This is the approximate date to sow your seeds. If you don't know your average first frost date, contact your country extension agency.
Top-Notch Cool Weather Crops
Even if you live in a lower zone, there is still time to plant certain crops. Obviously, corn doesn't grow particularly well in the frost and snow. Still, don't automatically rule out a crop just because your first frost date is rapidly approaching. Spinach, for example, can be easily over wintered provided that it has reached a good size before the first hard frost and is given some protection. Some root crops, like turnips, carrots and rutabagas, can be covered with a deep layer of protective mulch as temperature drop and harvested from under several inches of snow in mid winter (providing you can get to them, of course). Try to select "early" variety cultivars and remember that row covers and cold frames offer gardeners the ability to extend the growing season well into fall.
Here are some examples of good second season crops:
|Vegetable ||Approx. Days to Maturity |
|Beets ||55 to 60 |
|Broccoli ||70 to 80|
|Brussels Sprouts ||90 to 100|
|Cabbage (including Chinese) ||70 to 80|
|Carrots ||85 to 95|
|Cauliflower ||55 to 65|
|Collards ||60 to 100|
|Kale ||40 to 50|
|Kohlrabi ||50 to 60|
|Lettuce ||40 to 50|
|Mustard ||30 to 40|
|Onions (sets) ||60 to 80|
|Peas ||55 to 70|
|Radishes ||25 to 30|
|Rutabaga ||70 to 80|
|Spinach ||50 to 60|
|Turnips ||55 to 60|
Don't Forget to Water
No matter the season, vegetables require at least 1 inch of water per week and should never be allowed to dry out. Be aware that it's easier to over water crops in the fall, because as temperatures drop, the soil is able to hold moisture for longer periods of time.