How to Succession Plant for a Non-Stop Summer Harvest
The summer vegetable garden is ever changing and by early July, I’ve harvested the spring lettuce, spinach, peas, radishes and carrots. These empty spots in my raised beds can be succession planted with fresh seeds or seedlings to provide a late summer and autumn harvest.
There are many vegetables that can be planted in July and August. Before I grab seed packets and a trowel, however, I start with soil preparation. Healthy soil produces the highest yield. I amend my raised beds with compost or aged manure, working a 1” layer into the top few inches of soil. This is also a good time to apply a slow-release organic vegetable fertilizer. After the beds are prepped, it’s time to plant.
Vegetables can be direct seeded or transplanted. When the weather is hot and the soil is dry, direct seeding can be a challenge. Soil must be kept consistently moist until seeds germinate and are growing well. That means you may have to water once or twice a day. For that reason, I like to start with transplants for vegetables such as cabbage, lettuce and broccoli. Sowing the seeds indoors under grow lights gives the plants a month or so of pampering before they’re hardened off and moved to the garden. Alternatively, root crops such as carrots, beets and turnips and fast-growing vegetables such as bush beans, summer squash and cucumbers should be direct seeded.
Preparing the soil so that it’s ready for the author to direct seed a second crop of vegetables.
Since there are so many different growing seasons across North America, I recommend using two pieces of information to determine if you still have time to sow a particular crop: days to maturity and first expected fall frost date. For example, Sunburst summer squash takes 52 days to go from seed to harvest. If you sow the seeds on July 15th, you’ll be harvesting around Sept 5th. In my Halifax, Nova Scotia, garden, the first frost is typically in early October. So I still have time to direct seed Sunburst summer squash on July 15th.
The days-to-maturity information for each variety should be listed on the seed packet, in the company’s seed catalog or on its website. Also note that the number of days to maturity can differ for different crop varieties. Napoli carrots need about 58 days to go from seed to harvest, for example, but Purple Haze carrots require 73 days. Pick varieties that have time to mature in your region.
Vegetables to Plant in July and August
The carrots I harvest in autumn and even into winter are direct seeded in late July. I like to plant Napoli or Bolero, which are quick growing and exceptionally sweet. Carrot seeds need consistent moisture to germinate, so pay attention to watering in the summer heat. Thin to 1” to 2” apart when the seedlings are a few inches tall.
These tender carrots are the result of succession planting.
There are two types of radishes: spring and winter. Spring radishes, such as French Breakfast, grow very quickly. They are ready to pull only three to four weeks from seeding. In my zone 5 garden, I plant them every two weeks from mid-August to mid-September. Winter radishes, on the other hand, have larger roots and take longer to mature. Many, such as Watermelon radishes, need two months to go from seed to harvest. Read the seed packet so you plant them at the right time.
Fresh beets offer a dual crop of sweet, earthy roots and tender greens. Most need 50 to 60 days of growth. They should be direct seeded from late July through mid-August, depending on your region. Thin the seedlings 2” to 3” apart once they are growing well.
I love salad turnips such as Purple Top White Globe and Hakurei which, like beets, have delicious roots as well as edible tops. Hakurei is a farmer’s market favorite and very quick to grow. It has smooth white roots that can be harvested just six weeks from seeding.
Cabbage, Broccoli, Kohlrabi and Cauliflower
These related crops are ideal for summer seeding or transplanting. They will be ready to pick in mid to late autumn. Personally, I prefer to transplant cabbage-family vegetables rather than direct seed. Starting them indoors under my grow lights gives the young plants four to five weeks of ideal growing conditions and prevents damage from pests such as slugs and cabbage worms. You can direct seed if you prefer, but be sure to keep newly seeded garden beds well-watered.
Scallions, also known as bunching onions or green onions, are grown for their slender stems and white stalks. My go-to variety is Evergreen Hardy White, which I direct seed from early August to early September for autumn and winter harvests. I like to grow these plants, which are very cold tolerant, in my cold frames and poly tunnel so we can eat them during winter. Most scallion varieties reach a harvestable size two months from seeding.
Cucumbers thrive in the summer heat by growing quickly and yielding a bumper crop of crisp, delicious fruits. Most varieties require 55 to 70 days from seeding to produce a harvest. That means you can sow cucumber seeds in July in most parts of Canada and the United States. In very short-season areas, plant a bush type as they are the fastest to crop. I grow my vining cucumbers vertically on trellises and tunnels but if you have the space, they can sprawl on the ground. Bush cucumbers can also be grown on the ground or supported with tomato cages.
Like cucumbers, zucchini (or summer squash) are a fast-growing, heat-loving vegetable. Zucchini is first planted after the last frost in late spring, but I like to plant more seeds every 30 days until two months before my first expected frost date. Why? New fruit production begins to decline after a month, and succession planting means I get to enjoy a long season of high-quality fruits.
Beans are one of my favorite crops to grow in the summer garden. Most varieties need 50 to 55 days to produce and since the plants yield tender pods for about two weeks, it’s a good idea to succession plant more bush bean seeds every two to three weeks until mid-July. Provider, Cosmos and Mascotte are excellent choices for the home garden.
A mid-summer succession crop of bush beans.
Planting peas in summer? Yes! I love planting our beloved Sugar Snap peas in July. The summer-planted peas are ready to pick in early to mid-September. When selecting which peas to grow, read the seed packet carefully as many types grow tall and need strong supports.
Lettuce is the most popular salad green grown in gardens and it thrives in the cool autumn weather. However, lettuce seed doesn’t germinate well when the temperature is high, which makes summer sowing difficult. To get around this, I start my lettuce seeds indoors under grow lights. After a few weeks, I harden them off and plant them in the garden in mid to late August. Favorite varieties include Red Salad Bowl, Buttercrunch, Salanova and May Queen.
Arugula is a staple in our garden in spring, autumn and winter. When the weather heats up in late spring, any remaining plants bolt (send up flower buds) and are tossed in the compost. I wait to succession plant arugula until late August when the nights are cooler and there is typically more moisture. I seed arugula every two weeks until late September. This provides us with months of peppery arugula for salads.
Spring spinach is a treat after a long winter but, like arugula, it bolts quickly in early June. For spinach that lasts weeks, or even months, plant in late August through late September. I direct seed spinach and plant different varieties such as Seaside for baby greens and Bloomsdale for large crinkly leaves. Seaside grows very quickly and is ready to pick just 30 days after planting.
Kale can be grown two ways: as mature plants to provide large leaves, or as a baby green for tender salads. I grow it both ways as I love the aesthetic of mature kale plants in the autumn garden. It’s also great to have a non-stop supply of big leaves for kale chips. I direct seed or transplant these plants in mid to late July. For small leaves for salads, I direct seed a variety such as Red Russian in my cold frames, poly tunnel beds or garden beds in late August. Kale is very cold tolerant and with a simple cover, we harvest all winter.
With these tips in mind, I hope you will try your hand at succession planting this growing season.