The harvest from our gardens is our long-awaited reward for the effort and patience we put in earlier in the season. But often, it seems far too short. For many vegetables and flowers, the window of peak flavor and enjoyment is often only a week. 

By practicing succession planting and using varieties with varying maturities, we can extend our prime harvest period for each crop, and it isn’t really much more work at all. A few quick steps and you’ll be buttering fresh cobs of corn and eating well from your garden much longer than you may have imagined.

Succession Planting

Succession planting works well for single-harvest crops like sunflowers, sweet corn, or carrots, and for crops that tend to bolt and become unusable, like lettuces. For example, a traditional sunflower makes one big bloom per plant. After you’ve cut the flower for a bouquet, or allowed it to fade away in the garden, that’s it. If you planted a few more every 10 days or so, of the same or a similar variety, you’d have a much longer window of sunflower blooms to enjoy, perhaps two months of flowers instead of only a week and a half.

This method of succession planting (as opposed to planting an entirely different crop after the first is done) could also be called replanting. As long as temperatures are suitable and sufficient time remains before the frosts, we can plant the same crop again and again, spacing the sowings out over time. 

The art with succession planting is in the timing. Plant again too soon, and you’ll have more than one generation of plants ready for harvest at the same time. Wait too long, and you’ll have a gap where nothing is ready. 

A row of radishes, even though they are quick to mature and reliable growers, won’t all be ready to pick on the same day. A few will be ready a couple of days earlier, and a couple of stragglers will need a few extra days. Crop maturity rarely happens uniformly. With that in mind, we can assume a harvest window for a particular planting will last a week or ten days, perhaps even two weeks depending on the crop. Loose-leaf lettuces, for example, might be harvestable for three weeks if they don’t bolt. Look at the harvest window, and use that to time your succession planting intervals. A crop harvestable for only a week might be replanted every week or ten days. If the plant is harvested over a few weeks, a 2-3 week replanting window might be in order. 

Using Varieties with Differing Maturities

For single-harvest crops like beets, carrots, sweet corn, or even cabbage, planting several varieties with different maturity dates can extend the harvest window without replanting. In this case, extending the harvest is simply a matter of planning.

Key to making this work is choosing varieties with a large enough difference in maturity date to spread the harvests out. Remember, plant maturity, or the condition of being ready to harvest, isn’t an exact number, but a guideline. ‘Royal Crown’ turnips are described as needing 50 days to mature, but that number will vary based on soil fertility, moisture, temperature, and sunshine. They may be ready in 45 days in one garden or growing season, and not ready until 55 days in another. Use the numbers as a guide, and choose varieties with significant separation. 

Beets make an excellent example. A beet left too long begins to get pithy and less appealing, and mature roots can rapidly grow too large and get tough, so harvest is necessary at peak. If you’d like a longer window of fresh, sweet, just-right-sized beets, you can either succession plant them as above, or choose multiple varieties. Planting ‘Early Wonder’ (50 days), ‘Ruby Queen’ (60 days), and ‘Merlin’ (75 days), all at the same time, should yield a little more than a month-long harvest of beets at their peak.

This same idea can be used for nearly any crop, providing not only an extended harvest window but also the chance to trial different varieties for flavor, yield, and success in your garden. 

A note on sweet corn: Remember, supersweet (sh2) varieties are sensitive to cross-pollination from other corn types. If you are using different maturity dates to extend the sweet corn harvest, choose all supersweet (sh2) varieties or all non-sh2 varieties.

How it all comes together in the garden

Tailor your succession planting to your normal planting style. For example, if you direct-seed lettuces in the garden, you can simply direct-seed a new planting near the old one every 2 weeks or so until autumn, pausing in midsummer if your location requires it. As fall takes hold and the weather changes, shift to sowing them in a cold frame or low tunnel. However, if you have trouble with birds eating your seeds and so normally start lettuces inside and transplant them, do that, repeating at the correct intervals.

Practicing these ideas in the garden might look like a combination of succession planting and differing maturities. In the example below, week Zero is the week of your last spring frost, for illustration purposes. 

• Week Zero: transplant leaf lettuce, spinach, kale, and broccoli plants outdoors. Direct sow a second batch of lettuce, spinach, and kale in the garden beds. Start new broccoli seeds indoors. Plant out three varieties of beets with differing maturities. Sow a small batch of radishes. 

• Week One: Sow a second planting of radishes. Plant sunflowers.

• Week Two: Sow a third planting of leaf lettuce, a third planting of radishes, and plant a first planting of sweet corn, or plant two corn varieties of differing maturities. 

• Week Three: Transplant broccoli and start more indoors. Sow a fourth small planting of radishes. Sow a second planting of sunflowers, kale, and spinach. 

Keep going, replanting, until the crop either won’t mature before the heat shuts it down in the case of cool-weather crops, or until it won’t have time to mature before the autumn frosts. Count backward from your first average frost date, and add a fudge factor of about 10-20% of the maturity time to come up with the last planting for crops that are killed by freezing temperatures. The extra time is needed because plant growth and maturity normally slow as fall arrives. Those plants that will survive light frosts don’t need the extra time. ‘Ambrosia’ sweet corn needs about 75 days to mature, so adding about ten days to account for autumn growth yields a latest succession planting time of 85 days before your first fall frost. However, kale will grow right on past the frosts, and while its growth will slow in cooler weather, it doesn’t have a frost deadline like warm-weather plants. 

You may find, especially with cool-weather-tolerant crops, that a later planting seems to catch up to an earlier planting in spring. Many of our cool-weather veggies and greens, like kale, lettuce, spinach, chard, and peas, will grow in early spring and tolerate some light frosts. They can be sown as soon as the ground is workable, which is often nearly a month before our last spring frost. However, that doesn’t mean they germinate quickly then, or that conditions are optimum for growth. A week of weather just above freezing will result in little growth, even though these crops will survive. Thus, a later planting may seem to grow faster and may result in two batches ready at the same time. In this case, you may find that transplanting the first batch, after starting them indoors, solves this problem.