Succession Planting • Principles & Practices

Successive plantings of head lettuce at Six River Farm, Merrymeeting Bay, Bowdoinham, Maine

The methods below run from the simplest to the most involved. With good records and some experience, you can mix methods, borrow ideas from other growers and develop your own for even better results.

1 • INTERVAL PLANTING
One crop, one variety, sown again at regular intervals.

Selecting Crops for Interval Planting

Crops that mature quickly are especially good for planting again and again through the season. How often to sow depends on the typical days to maturity (DTM) under normal growing conditions. Quick greens might go in every 7 days, for example, and summer squash every 30. For recommended intervals by crop, see our charts:

Calculating Interval Seeding Dates

To plan sowing dates, use our Succession-Planting Calculator. It works out dates for staggered plantings, counting forward from your last spring frost or back from your first fall frost.

Hensley’s Succession-Planting Calculator (XLSX)

Enter your first frost date and your variety's days to maturity, and the calculator lists dates for each succession.

Remember that frost dates, latitude, zone, weather and growing practices all affect days to maturity. After midsummer, for example, most growers space plantings closer together, because crops mature more slowly as days get shorter and cooler. Good records through the season help you dial in the best schedule for your site.

• Succession planting calculator (XLSX)
• Look up average frost dates for your area

Interval Planting + Indoor Seed Starting

Starting some seeds indoors while also sowing directly can add extra successions. Just start transplants of crops you'd usually direct-sow, such as arugula, cilantro, cucumbers, parsley, spinach, squash and sunflowers, and sow the direct-seeded planting when you set them out. The transplants are ready first, and the direct-sown crop follows a few weeks later.

2 • HARVESTING PROGRAMS
One crop, several varieties with different maturity dates, all sown at the same time

Many crops are bred for specific traits such as heat or cold tolerance or doing well in low or high light. Within one crop, some varieties do best in cool weather and others in heat, some as days lengthen and others as they shorten. Grow just one variety and it will probably underperform at some point in the season.

Leek harvest program

Growing several varieties lets you cover a longer season with consistently good quality. Our harvest programs pair varieties with different days to maturity so a single planting can be harvested over a longer period.

Our leek harvest program, for instance, plants several leek varieties at the same time, maturing in roughly 75 to 120 days, so you can keep harvesting from summer through fall and into winter.

For perennial crops such as berries, harvest programs are one of the main ways to lengthen the picking season.

See our harvest programs:

• Blackberry • Harvest program
• Blueberry • Harvest program
• Brussels Sprouts • Harvest program
• Leeks • Harvest program
• Raspberry • Harvest program
• Strawberry • Harvest program

3 • PLANTING PROGRAMS
One crop, varieties suited to different seasons, sown one after another

Our planting programs pair varieties that differ in days to maturity and seasonal strengths, each sown at its own time of year.

Planting programs, especially combined with season extension, can give you the longest harvest window. For broccoli, for example, you might plant one variety in spring and another in summer to keep heads coming from summer into late fall.

Our Sunflower Charts show how interval planting, harvest programs and planting programs can be combined to get the most out of succession planting.

See the Planting Program pages in our growing library for how to put these programs to work:

• Broccoli, mini and sprouting • Planting program
• Broccoli, standard heading • Planting program
• Cauliflower • Planting program
• Lettuce • Planting program
• Radicchio • Planting program
• Specialty radish • Planting program
• Spinach • Planting program
• Sunflower • Planting program

4 • SEASON EXTENSION TECHNOLOGY

Last, protected growing can push your season well past its usual limits, so you can produce earlier in spring and later into fall and winter. Match the protection to the crop and your expected frost dates.

A caterpillar tunnel provides moveable protection from the elements

• Crop protection
• Winter growing guide
• Overwintering flowers guide

See our season extension and winter growing library for more.