While we busily harvest the great bounty of fruiting crops, nutritious leaves, roots, flowers and herbs erupting from the garden in mid July, the sneaking thought that winter is coming plays like creepy horror film music in the back of my mind. We're all doing our best to can our tomatoes and make our cabbage into sauerkraut for use in the winter months. Another method for staying food secure heading into winter is to plant fall crops in summer. To be honest, in many regions this can be a difficult task. The high summer sun, the pest pressure and shortening days make this a true feat, but if plants can germinate, become established and are cared for during periods of drought, the fall garden can be a spectacular display and a bountiful store of homegrown nutrition.
Harvest and Remove Spent Spring Crops
Whether you've got acres of crops, a backyard garden or a patio covered in containers, it can be difficult to say goodbye to your spring sown produce. These plants have been good to you, produced beautiful food and maybe they are still limping along with something to offer, but at a certain point you've gotta rip off the band-aid and make room for something new. Some plants that tend to finish up their season midsummer that can provide space for a fall sowing include garlic, radishes, turnips, broccoli, beets, cabbage, carrots, potatoes, onions, cauliflower, peas, and spring greens among others. Your tomatoes, peppers, eggplant, okra, flowers, and other long standing summer crops may still be heavy into production and may not finish up in time for a fall sowing in their place.
Determine What to Grow Based on Your First "Hard" Frost Date
When you set out to plant your early spring crops, stray late frosts can threaten your young plants, especially hard frosts, or those that dip well below 32 degrees Fahrenheit. When thinking about planting a fall garden, this is slightly different as the plants will be reaching maturity as the stray light frosts of 29-32 degrees Fahrenheit roll in and will need to complete their life cycle before the hard stop initiated by a hard, killing frost of around 24 degrees Fahrenheit or below. Most all of your summer sown, fall crops will tolerate a light frost and can even continue to grow as temperatures dip into the low forties. Many of your brassicas crops will actually sweeten as the temperatures cool and light frosts concentrate their sugars in the field. Knowing when the average hard frost of fall occurs in your region is an important first step in creating your fall planting plan. Counting back 12-14 weeks from your average first frost date in the fall will give you a good window for sowing fall crops in the summer.
Make a Plan Based on Your Usable Space and Prep it
Making plans for your fall harvest in the winter when you're making your spring plans can help you manage your space most efficiently and also help you make the hard call to pull something up that you may be tempted to leave in the ground when summer arrives. That being said, there is some flexibility in midsummer when the soil is warm and its easy to get crops to germinate. Whether you've mapped out your plantings or you're just deciding to wing it, the space that becomes available in July can be divided up into crop types that you, your family, and or customers favor. Once you've removed the spent plants of your spring sown crops, it is important to remove any additional debris left behind, weeds, and any stalks or root balls that may send up shoots and/or harbor harmful pests. A clean bed for seeding and transplanting can be amended with a light application of fertilizer and a dose of compost, as a boost for the young plants to come.
Caring for Direct Seeded Fall Crops
While the soil temperature is warm enough for speedy germination, sometimes heat and especially soil dryness that can occur at the peak of summer can be hard on direct seeded crops. These crops that did so well in the spring did so because the environment was ideal for their establishment and growth. The heat of summer, especially as you head south, can be a lot for a young seedling that thrives in cooler weather. It is important to help mimic the conditions of spring as much as you can for these crops to germinate. An important part of that is keeping the bed consistently moist during the germination stage. Until the seeds come up, the bed must be watered. If there's no rain on the forecast, watering your carrot bed everyday may be a reality. While this may not be a big deal for quick germinating crops like greens, turnips and radishes, your beets, carrots and fall/winter spinach may need your help to get growing. Transplanting things like beets and rutabagas can also help you manage your space and ensure a decent stand against the odds of summer. Watering as they continue to mature will help the plants cope with the stresses of the summer heat. Watering too much, especially in containers, is also a possibility, so keeping a consistently moist but not soggy soil will prevent the seeds from rotting before they have a chance to develop.
Caring for Transplanted Fall Crops
Whether you're starting your fall transplants of kale, head lettuce, broccoli, kohlrabi, cauliflower, swiss chard, or collards in a greenhouse or even in your own house, it is important to acknowledge that they are crops that typically thrive in cooler weather and have to do the hard job of growing in the less than ideal conditions presented to them during summer. While starting the seeds in your greenhouse can help lead to quick germination, it may be important to move the transplants to a cooler location once they are up and beginning to grow true leaves. Some people use shade cloth to protect young transplants from the harsh summer sunlight. Starting these plants in your house can allow the crops to have a more temperate nursery stage, but hardening off the transplants to the conditions they will face in the garden or field gradually will prevent them from suffering sun damage and heat stress. Transplanted crops do well planted on a cloudy day ahead of projected rain and will need to be watered during periods of drought as it can have adverse effects on the development of your plants, especially broccoli and cauliflower. Pest pressure is also peaking at this time of year and protecting your plants with lightweight floating row cover or insect netting may be important in your region.
Consider Using Mulch
In a wet, cool year, this may not be the solution you seek, but in a hot, dry season mulch can really help your plants thrive through heat stress. Mulching the beds that your transplants or seedlings are developing in can conserve soil moisture and also lower the temperature of the soil for your crops that prefer a cooler growing climate. Even mulching the pathways of your garden can help provide habitat for organisms that do good work for your crops, but do not tolerate exposed soil that is consistently scorched by the sun.
Managing Heightened Pest Pressure
As the summertime pollinators flutter from flower to flower and the air is inundated with hovering insects of all kinds, your plants are engaged with the most awakened version of your farm or garden. At peak summer, everything from the microorganisms in your soil to the birds in your trees are playing a role in the success of your garden and this highly active state is constantly trying to achieve balance. Unfortunately for us, the big picture balancing act doesn't always result in the prosperity of our plants. Where a deficiency in the soil persists and/or climatic variables abound, plants are unable to fully develop the faculties necessary for their own protection. In a stressed growing environment such as periods of high heat or drought, plants can become vulnerable to insect pests. Managing insect pests can include timing plantings based on insect life cycles, hand removing pests from developing plants, using Omri approved insect controls and using lightweight row cover or insect netting. This is very important for summer sown, fall crops as they will be especially vulnerable to the peak pressure of insects as they are forced to weather conditions they do not favor.
Fall Crops (Can) Last Longer
As the heat begins to recede in fall, your summer sown plants will truly thrive. Seeding these crops in the summer means that they will develop slower than they would in a springtime sowing and this should be considered when selecting varieties. Adding an additional 2 weeks to the days to maturity average of the crop can help you accommodate the extra time needed for development. The days are shortening as opposed to lengthening, which contributes to a longer time needed for maturity. When the cool weather hits, many summer pests will be ending their life cycles in preparation for winter dormancy which can make for a less buggy fall garden. The cooler weather not only slows the growth of your crops, but it can hold onto the freshness and eating quality of your crops for longer harvest windows.
Harvest Crops Before Full Maturity
Season after season, your plan and the implementation of your summer sown, fall crop plan will be more informed by all of the experience and wisdom you garner along the way. Even if you find that some of your summer sown crops don't make it to peak maturity before the hard frost of fall, the crops are likely flavorful and nourishing harvested as baby leaves. Broccoli and cauliflower that don't produce heads will still produce beautiful leaves that are reminiscent of kale and collards. Turnip greens are, in my opinion, basically as delicious as turnips themselves and beet greens are an amazing addition to salads. Your under developed carrot crop just might overwinter, but if that doesn't seem possible in your region, carrot green pesto is a real thing. All in all, harvesting tasty, homegrown food in the fall is a great way to end and even extend the season. If you find yourself overwhelmed by your summer bounty, there's no shame in throwing in a cover crop as a good deed for the soil and ecology of your land and as a way of improving the soil for what you will sow next year.