Succession Planting • Principles & Practices

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

We start with the simplest method and proceed to the more evolved. As you keep records and gain experience, you can combine methods, adopt those of others, and innovate your own to achieve even greater results.

1 • INTERVAL PLANTING
Same variety, same crop, sown at successive intervals.

Selecting Crops for Interval Planting

Some crops are particularly well suited for successional plantings throughout the growing season because of their relatively short time to maturity. Timing of sequential plantings is based on the average days to maturity (DTM), assuming standard growing practices. For example, fast-growing greens might be sown every 7 days while summer squash might be sown every 30 days. For a list of crops and their recommended succession intervals, refer to our interval charts:

Calculating Interval Seeding Dates

To forecast seeding dates, try our Succession-Planting Calculator. You can use this calculator to determine dates for sequential, staggered plantings—whether counting forward from last regional frost date in spring or backwards from first regional frost date in fall.

Johnny's Succession-Planting Calculator (XLSX)

Input your first frost date and the average days to maturity (DTM) for your chosen variety, and the calculator will display appropriate dates for sequential plantings.

Keep in mind that local frost dates, latitude, growing zone, climatic variables, and cultural methods will influence days to maturity. After midsummer, for instance, growers at most latitudes start timing successive plantings more closely together, as crops will mature more slowly as the days grow shorter and cooler. Good recordkeeping during the growing season can help you home in on the ideal planting schedule for your location and growing conditions.

• Succession-Planting Calculator (XLSX)
• Find the average first and last frost dates in your region

Interval Planting + Indoor Seed Starting

You can combine indoor seed-starting with direct-seeding to maximize the number of successions you can achieve. This simply requires starting seeds indoors for many crops you might normally direct-seed, such as arugula, cilantro, cucumbers, parsley, spinach, squash, and sunflowers. When you transplant the seedlings outside, you can complete your direct-seeded planting. The transplanted crop will be ready for harvest first, followed by the first direct-seeded planting a few weeks later.

2 • HARVESTING PROGRAMS
Same crop, different varieties with differing maturity dates, sown concurrently

Many seed crops are bred and selected for particular traits such as heat or cold tolerance or ability to thrive under lower or higher light conditions. Within a particular crop, some varieties perform better in cool weather and others in warm weather, some under increasing daylength and others under decreasing daylength. If you grow only one variety of a crop, you may find it falls short of its potential at some point or another during the season.

Leek Harvesting Program

By growing several varieties, you can span a longer season and still offer consistently high quality produce. Our harvesting programs recommend sowing multiple varieties with different days-to-maturity (DTM) to spread the harvest across time from a single planting.

For example, our leek harvesting program involves concurrently planting several leek varieties that require from 75 to 120 days to mature, to allow you to successively harvest leeks from summer through fall to winter.

Harvest programs are also a primary way of extending the harvest window for perennial crops such as berries.

Explore our harvesting programs:

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

3 • PLANTING PROGRAMS
Same crop, different varieties with differing seasonal adaptations, sown successively

Our planting programs recommend sowing different varieties with different days-to-maturity (DTM) and differing seasonal adaptability, at different times of the year.

Planting programs, especially when combined with season-extension techniques, can allow for the maximal harvest window across time. For example, to achieve a long harvest window of broccoli, one might plant one variety in spring and a different variety in summer, and in so doing, achieve a continuous harvest from summer through late fall.

Our Sunflower Charts nicely demonstrate how all three of the above strategies—interval planting, harvesting program, and planting program—can be creatively combined to make the most of succession-planting concepts.

Visit the Planting Program section of the Grower's Library for details on implementing these programs:

• Broccoli, Mini & Sprouting • Planting Program
• Broccoli, Standard Heading • Planting Program
• Cauliflower • Planting Program
• Lettuce • Planting Program
• Radicchio • Planting Program
• Radish, Specialty • Planting Program
• Spinach • Planting Program
• Sunflower • Planting Program

4 • SEASON EXTENSION TECHNOLOGY

Finally, protected cropping bears mention as it can significantly expand the limits of your growing season, allowing for production earlier in spring, later into fall and winter. You can tailor the protection to the crop and anticipated frost dates.

A caterpillar tunnel provides moveable protection from the elements

• Protect Your Crops
• Winter Growing Guide
• Overwintering Flowers Guide

Visit our Season Extension & Winter Growing Library to learn more.