As the cool fall weather moves in, some gardeners are ready to rip out their summer gardens and plant some cool-season vegetables, while others hesitate to say goodbye to those delicious cherry tomatoes or the peppers that finally started to ripen. In southern climates, summer veggies will continue to grow with little threat of frost and snow, while in northern zones, without protection, many warm-season plants will soon be lost to early frost.
The good news is that no matter what region you’re gardening in, there are plenty of ways to ripen up those last few green tomatoes and extend the season for a few more weeks or even months.
Prune Excess Vegetation
At this point in the season, chances are your plants have put on a lot of vegetative growth. If you’re growing in a warm southern climate, there may still be plenty of time for that new growth to set new fruit that will ripen this season, but for most gardeners that’s not the case. New growth takes a lot of energy and blocks valuable sunlight from your plants. By trimming off excess vegetation from the top of your fruiting vegetables, you’re able to redirect that energy into the fruit while also increasing sun exposure.
While you’re at it, pluck off any flowers and young fruit that won’t have time to fully ripen.
Remove Diseased Plants
By fall, many of us have spent a fair amount of time combating pests, fungi, and diseases. Any plants that are overrun with aphids, powder mildew, or any other ailment should be removed now to prevent the problem from spreading to other plants. Some gardeners will compost diseased plants because they expect the heat generated by the composting process to kill off the disease. Though this is often the case, removing these plants completely is recommended to avoid the risk of potentially reintroducing the problem back into your garden.
Water Before Cold Snaps
With temperatures dropping and precipitation moving in, now is the time of year when gardeners cut back on watering or shut off irrigation all together. It’s always important to conserve water and never good for your soil to be oversaturated, but watering before a cold snap is just as important as watering before a heat wave. Well-irrigated soil will retain more heat during the day and release it to warm the plants as frost moves in. Always be sure to give your plants a healthy drink the day before frost is predicted.
Provide Frost Protection
Few things will bring your summer garden to a close quicker than a hard fall frost, but there are a few simple and effective ways to protect your tender plants. The first step is to determine what level of frost protection you’ll need and when to expect the first frost in your area. There are a variety of resources available (such as the United States Department of Agriculture and the Old Farmer’s Almanac) to help you find that information, including websites that allow you to search by zip code.
A thick layer of mulch is a great way to retain soil moisture and insulate a plant’s roots, but mulch will actually increase the plant’s risk of frost damage by preventing heat and moisture from being released to warm the air. In order to effectively insulate your plants, be sure to cover them completely. Low-growing plants can be mulched over with a loose layer of straw, while taller plants can be covered with sheets, tarps, or even newspaper.
For the best protection, frost cloth or row covers will provide substantial frost protection while maintaining airflow and allowing sunlight to reach your plants. To keep the weight off of tender plants and increase airflow, try creating a simple hoop house by building arches of 1/2-inch PVC pipe and draping frost cloth or clear plastic over the structure. After planting cool-season veggies, the hoop house can be kept up and draped in shade cloth. This will protect tender greens in the event of a fall heat wave. It can also be maintained with frost cloth to protect tender greens through winter.
Fruiting vegetables, like tomatoes and peppers, are heavy feeders, so you can’t just feed them once at planting time and expect them to keep producing large, abundant fruit all season long. In order to bulk up those beefsteaks and support that heavy crop of cucumbers into fall, give them all a healthy feeding now. Apply whatever fertilizer you’ve been using this summer, and if you’re still searching for a good vegetable fertilizer, look for one that’s lower in nitrogen with a good amount of phosphorus and potassium for your fruiting vegetables.
Location, Location, Location
If your prized pepper plant is growing in a pot, all you have to do to protect it from frost is bring it indoors for the night; or sometimes just placing it beneath a tree or awning will do the trick. However, with in-ground plants it’s not that simple. At this point in the season the location of your plants is set, but understanding what areas in your garden are most susceptible to frost will help you estimate the level of frost protection your plants might need.
Areas of your garden that are exposed to afternoon sun retain more heat in the soil, which will slowly release overnight. Gardens growing among trees or buildings or along fences, especially those areas protected from the North, are less susceptible to chilling winds and frost. As elevation increases, air temperatures decrease; however, topographic depressions will trap cold air as it settles overnight. Pay attention to the microclimates in your garden, and don’t be discouraged when your neighbor’s tomatoes survive the frost but yours do not.
Interplant Cool-Season Vegetables
If you’re having trouble deciding whether you want to squeeze a few more harvests out of your summer garden or get going on your winter veggies, try interplanting to maximize your growing space, but the established plants will also help by shading young tender greens as they establish. This process allows you to get a head start on your winter garden while still allowing your warm-season veggies to finish out the season.
For some gardens, especially those in northern climates, extending your summer growing season can be a major undertaking. If this is your first season trying these techniques, start small. Choose just one section of your garden or a few of your healthiest plants. Keep in mind; larger tomatoes such as beefsteaks require more sunlight to ripen than smaller tomatoes, so those should be the first to go if you have to choose.
Every gardener will experience different levels of success with these techniques. Figure out what works best for you and your garden, then fine-tune them each season to get the most out of your summer vegetables.