Kitchen Garden School: June

Kitchen Garden School: June

Welcome to the sixth lesson of Kitchen Garden School at Cornell Farm. This month, we will officially welcome the start of summer, which means that — if you haven’t already — it’s time to plant your summer veg! As we harvest our remaining cool-weather crops, we're fully transitioning over to summer fruits and veggies, with an eye towards the principles of succession planting. Keep reading and watching for a special "show and tell" in our Kitchen Garden display beds with our lead kitchen gardener, Cynthia DuVal!

Summer Succession

In June, soil temperatures are steadily above 50ºF, which means most warm-season crops are ready to go into the ground. Some, like melons and cucumbers, prefer even warmer soil temperatures in excess of 65ºF, so it's a good idea to keep an eye towards the weather when deciding when to plant. If, like us, you have a few lingering cool-weather greens and veggies in your kitchen garden, it's absolutely okay — and even encouraged — to inter-plant your warm-season crops among these plants. That's succession planting at work! As the new plants grow, they will provide cooling shade to your remaining cool-season crops as they finish up.

In the video above, Cynthia demonstrates planting tomatoes and peppers, but there are a wide variety of crops available to home gardeners this time of year, and to extend your harvest, you can select different varieties of the same crop like Cynthia has done. Here's a quick overview of some of our favorite summer veggies:

  • Beans are a fantastic summer vegetable because they are relatively quick to begin producing (generally around 60 days), even when direct sown into warm soil. You will see both "pole" and "bush" types, which have similar advantages to indeterminate and determinate tomatoes, respectively. Bush beans, being more compact, don't require staking or trellising, and while they mature faster, they also produce for a shorter window. Pole beans, on the other hand, produce for an extended season on tall vines that require support, but that make excellent use of vertical space in the garden.
  • Cucumbers are truly warm-season plants, so waiting until June to plant is a good idea in climates like ours that enjoy a relatively long frost-free growing season. Although there are "bush" types that have been bred for small spaces, most cucumbers grow on scrambling vines. For best fruit quality and efficient use of space, they can be trained to grow on a trellis.
  • Eggplants have similar growing requirements to tomatoes and peppers. And while they generally need less support than tomatoes, it's a good idea to stake them or otherwise provide support, which is especially important as the fruits begin to develop and weigh down your plants.
  • Melons have similar needs to their cousins, the cucumbers. These plants like it hot, and because they can take up quite a bit of real-estate, it's a good idea to give them plenty of room to spread out. The fruits benefit from being kept off the ground with some sort of barrier to help protect them from rotting. They can also be trained on a trellis, with a sling made of old hosiery to hold the maturing fruit.
  • Peppers are often classified as "sweet" or "hot," and have similar growing needs to tomatoes and eggplants. They like it hot, and are good candidates for growing in a large pot where their soil is warmed by the rays of the sun. If grown in pots and moved into a greenhouse over the winter, they can even be grown on year-after-year with good success.
  • Summer Squash and Zucchini are distinguished from winter squash by having fruits with thin, edible skin that are harvested immature while the plant is still growing. These vining plants are prolific and can spread out quite a bit, but there are also more compact cultivars available, many of which have "Patio" in the name or description. The flowers are also edible, and are delicious when stuffed and fried!
  • Tomatoes are classified as determinate or indeterminate growers, meaning they will be more compact and bushy or tall and vine-like, respectively. Indeterminate tomatoes require more staking, and can benefit from suckering (pruning some of the new growth), but will produce for a longer season, as they will keep growing and flowering until they are knocked back from frost.
  • Winter Squash (including Pumpkins), in spite of the name, are grown in the summer. They require a long season to mature, but can be stored for a relatively long time — through the winter, in many cases — compared to their summer squash cousins. This is thanks to their thicker skin, which develops as the plants are left to mature on the vines.

Summer veggie starts will need to be kept moist when first transplanted out in the garden, then watered regularly throughout the heat of the season to keep your plants healthy. Deep watering at the soil surface is the best option, and is far preferred to overhead watering with a sprinkler. Whenever possible, try not to splash water onto or otherwise wet the foliage of your plants, which can encourage fungal diseases to take hold in your veggie patch. Then, with veggies like tomatoes, you can begin to let plants dry out a bit more between waterings when you notice fruits starting to mature.

A Time of Transition

Gardening, like all of life, is often about trying new things. Sometimes they work, sometimes they don't, and occasionally, there are hard decisions to be made. In the video below, Cynthia walks through a few other garden areas to celebrate her succession successes, talk about her plans, and offer a few words of encouragement to gardeners encountering the less-than-perfect.

One issue that gardeners will often run into this time of year is bolting — when leafy greens send up a flower stalk — which can seem to happen overnight! Unlike for fruiting crops like tomatoes, which we want to flower and set fruits, the appearance of a flower stalk on your lettuce or cabbage signals that the plant has entered the end of its life cycle and has begun to put all of its energy into producing seeds. From the plant's perspective, this is all fine and well, but for gardeners, bolted greens often mean a missed opportunity for harvest, as their leaves often take on an unpalatable bitter or woody taste.

If you look out into your garden this time of year and notice that your cool-season greens have begun to bolt, don't despair! Sample a few leaves to see if you can salvage the harvest, and if not, pulling out a few plants means creating more room to plant something in their place. Alternately, you can leave them in place to provide flowers for the pollinators and seeds you can collect for future sowing. We've heard it said that the difference between opportunity and adversity is just a matter of perspective.

Other Activities & Resources

Check out a few of the tasks you can undertake in the kitchen garden right now, along with the following "recommended reading."

  • Read the June chapter of The Maritime Pacific Northwest Gardening Guide from Tilth Alliance (pp. 56-67 in the second edition). Pages 60 and 61, in particular, offer a good overview of some of the beneficial insects you may encounter in the garden.
  • This month, there are several relevant readings scattered throughout Plant, Grow, Harvest, Repeat by Meg McAndrews Cowden. If you go to the index and look for "summer gardening," that should be a great start!
  • This is a good time to check out our guide to growing strawberries, including some good terminology to know when shopping for these sweet summer fruits.

      June Planting

      Check out the host of plants that can go in the ground now that summer is nearly here.

      • Now that soil temperatures have stabilized above 50ºF, starts of warm-season crops like tomatoes, peppers, zucchini, and squash can go into the ground!
      • Sweet potato starts (often called "slips") can go in the ground in June, although keep in mind that they want soil temperatures in excess of 60ºF. To warm the soil where you want to plant sweet potatoes, some gardeners lay down black plastic to trap heat.
      • Corn is another heat-lover, and while not as commonly grown in home gardens, can do quite well when grown on a smaller scale.
      • Large-seeded crops like beans can be direct-sown this time of year, as can annual sunflowers!
      • Don't forget about other flowering edibles that can be grown in your kitchen garden to attract pollinators, including borage, calendula, nasturtiums, marigolds, scented geraniums, and more.
      • We have a fantastic selection of fruit trees, shrubs, and vines that are flowering and setting fruit. Look for apples, pears, persimmons, figs, blueberries, currants, raspberries, kiwis, pomegranates, and more.
      • If you have the space, perennial vegetables like artichokes, cardoons, and rhubarb can still be planted this time of year.
      • Look for unusual edibles like yacón, Jerusalem artichokes (which are actually a type of sunflower), Mexican blueberries (which are actually a type of fuchsia), and others this time of year. We always try to have a few unusual edible plants in stock at any given time; stop by to see what we have now!

      Connect With Us

      If you have questions about edible gardening or would like help selecting plants, our knowledgeable team is always happy to assist you in the Kitchen Garden Greenhouse. Cynthia often gives informal tours of our display beds, so feel free to stop by for a quick walk-around! For help from afar, you can reach out to Cynthia and our Kitchen Garden team directly at

      We are also excited to share that, for those wanting more individualized assistance with their kitchen gardens, Cynthia is also available for personalized 90-minute Garden Coaching Sessions held in your very own garden.