Recommended Methods for a Continuous Supply
In market farming, one of the keys to success is the ability to sell a wide variety of high-quality produce over a long period of time. A good selection attracts customers; quality and availability keep them coming back for more. To achieve the goals of diversity, quality, and continuity, scheduling is all-important. We recommend you think not just about scheduling your plantings, but also about scheduling your harvests.
- Variety Selection by Season »
- Different Days to Maturity »
- Succession Planting at Intervals »
- Season Extension Technology »
Variety Selection by Season
Vegetable crops are bred for various traits, including heat and cold tolerance. Within a crop, some varieties perform better in cool weather and some in warm weather. If you grow only one variety, you may find that it falls short of its potential at some point or another during the season. By growing several varieties, you can span a longer season and still offer consistently high quality.
To help you choose the right varieties for your seasons, Johnny's has created Planting Programs for four of the most important crops: Broccoli, Cauliflower, Lettuce, and Spinach. The Planting Programs recommend the best varieties for each season. For example, in the lengthening days and increasing temperatures of spring and early summer, it's best too choose a slow-growing variety with heat tolerance. For harvesting in the shorter, colder days of fall, it's best to choose a fast-maturing variety with cold tolerance. The Planting Programs emphasize these differences, so it's easy for you to choose the varieties that will provide you with a marketable crop over the longest possible period in your climate.
For example, Johnny's Head Lettuce Planting Program lists varieties by Early Season, Mid Season and Late Season. The Early Season varieties are for planting in cool weather for warm-weather harvest; they are selected for quick growth so they make full-size heads before it gets hot. Mid Season varieties are selected for their heat tolerance, that is, resistance to bolting and tipburn. Late Season varieties for planting in hot weather for cold-weather harvest are selected for cold tolerance and disease resistance.
Different Days to Maturity
Another strategy for spreading the harvest over a long period is to plant several varieties with different days to maturity. This is the easiest strategy, too, because you can plant them on the same date and they will naturally mature at different times.
Sweet corn is a good example of this efficiency. If your customers love bicolor sweet corn, you can plant Trinity, Luscious, and Montauk, which will mature at approximately 68 days, 75 days, and 81 days. Johnny's Sweet Corn Comparison Chart lists varieties by Days to Maturity, so it's easy to choose several varieties of your favorite types.
Sunflowers also do well with a single planting of different varieties. The ProCut Series of single-stemmed sunflowers blooms in just 50 days, the Sunrich Series in 60-70 days, and the Sunbright Series in 70-80 days. Plant all three varieties on the same day and you can be harvesting sunflowers for up to a month. See Johnny's Sunflower Comparison Charts for more details, or read our articles on Succession Planting Sunflowers and How to Choose Sunflower Varieties.
We have also developed a Leek Program to help take some of the guesswork out for this crop.
Succession Planting at Intervals
The most common type of succession planting is to make multiple plantings at set intervals to ensure a longer harvest period. In general, you want to make your first planting, wait an interval equal to the harvest period of the variety, then make a second planting. For example, your first planting of bush beans might produce for about two weeks, so you want to make your second planting two weeks after the first so it reaches maturity right when the first one is finished.
This is trickier than it sounds because many factors influence days to maturity and harvest period. Crops that are planted early in the season may grow more slowly than those planted later, when days are longer and temperatures warmer. In fact, a late spring planting will sometimes catch up and mature at the same time as an early spring planting if the interval is too short.
The only way to get really good at succession planting is to keep records for each variety: when you plant it, when it's ready for harvest, and when it's finished. Over time, you'll be able to tweak your planting dates to ensure a smooth, even supply.
If you're just getting started, you may want to take a look at Johnny's Interval Succession Planting Charts. Alternatively, peruse Johnny's General Guidelines for Between-Planting Intervals for beans, beets, cucumbers, kale, lettuce, melons, radishes, summer squash, sweet corn, and turnips. We have also developed an online Succession Planting Calculator to help you with this process.
Season Extension Technology
Finally, protected cropping can help you extend your season significantly in spring and fall. Use several types of season-extension structures to tailor the season extension to the crop. The possibilities are numerous. Here are just a few examples:
You also can use a combination of transplants and direct seeding to effectively succession plant. Grow transplants of crops you normally direct seed, such as arugula, cilantro, cucumbers, parsley, spinach, squash, and sunflowers. When you plant them outside, direct seed some of the crop at the same time. The transplanted crop will be ready for harvest first, and the direct-seeded crop will mature a few weeks later.
Putting It All Together
Succession planting may seem complicated at first, but it becomes second nature over time. Start with a few main crops and project your harvest dates, then use these four strategies to find opportunities to extend the harvest. Do the same thing with additional crops next season. Try a few new varieties from the Planting Programs to see how they produce for you. Experiment with high tunnels and low tunnels.
Keep track of everything, and analyze the results. You'll soon be on your way to creating a planting plan that provides abundance — and strong sales — over the longest possible season.
- To learn more about succession planting, including links to specific interval charts and planting programs for a continuous supply, see Johnny's Succession Planting Overview.
- Scheduling Vegetable Plantings for Continuous Harvest, by Janet Bachmann (2008), from the National Sustainable Agriculture Information Service.