Guest Contributor: Cassey Anderson, Horticulture Agent, Colorado State University Extension
Peas in the summer? Yes, you can! If you've already pulled your carrots, or lost some seedlings to the critters, don't let that space go to waste! Even in the heat of summer, you can still plant for a late season harvest. Discover the best cool and warm season crops to plant now to add to your garden bounty.
Midsummer in the peak of the warm season may seem like a strange time to discuss planting and planting cool season crops but maybe your spring didn’t go as planned, you had some early garden losses or opened some more space in your garden that you want to fill with tasty goodness. Let’s discuss some vegetables you can grow for a quick harvest, and how to plant them with success in the summer heat. Some you may harvest while the heat of summer is on, but others can give you a great fall harvest.
Check out our companion post on Planting in July here.
COOL SEASON CROPS
To figure out exactly when to plant try to find your local area’s first frost date in the fall to determine when you should plant. Some crops can tolerate cool but not cold temperatures; some can tolerate light frost (28-32 F). If your crop takes 30 days to maturity and is killed by frost, you can plant as late as 5 weeks before your estimated final frost. If your crop takes 60 days to maturity but can tolerate light freezes you may be able to plant 9-12 weeks before your last frost date. Generally, planting in mid-July or so can give you plenty of time for many cool season crops.
Leafy Greens
Planting leafy greens in midsummer can have its pros and cons. On the one hand, soil temperatures are warm, and the sun is high so germination should happen quickly and easily. However, temperatures are high so keeping sufficient moisture around the seeds to enable germination can be a challenge. Beyond basic watering and amending with organic material to help with moisture retention, there are several approaches you can use to get better germination rates. See our Watering 101 post here.
A Note on Shade
Shade cloth, light mulch, or consistent overhead watering can all reduce ambient temperatures and help with germination. Shade cloth can be purchased with varying levels of shade reduction, typically between 30-70% reduction. A 40% shade cloth can do a lot of good in reducing temperatures and retaining moisture allowing seeds to germinate. If you mulch your garden beds you may be able to put a very thin (1/2” or less) layer of mulch on the soil to retain moisture. Especially during the first week or so after planting seeds, you will want to monitor your crops vigilantly and keep the soil consistently moist, but not wet. See our Shade 101 post here.
Root Veggies
Another reliable mid-season crop type is root crops such as radish, beets, and carrots. Germination can take a little longer than with leafy greens so you can use some of the approaches above and carefully monitor your soil moisture to be sure that the soil doesn’t dry out. For carrots, one unique approach is to add a layer of sand just above the soil and plant your carrot seed shallow. This will reduce the development of soil crust if the soil does dry out and help the seedlings to emerge. You can also place damp burlap or other cloth over the soil surface, just be sure to check and remove it as soon as you see seedling emergence, so the carrot doesn’t grow through it.
Peas
While peas don’t produce well peak season - they like shorter days- they can be a good choice at the end of the season for a harvest. If a hard frost is imminent and pea pods haven’t matured yet, you can use the flowers and tendrils in salads as well. Start your peas when you have about 8 weeks left in the growing season before a hard frost – they can push through temperatures down to about 28F
WARM SEASON CROPS
Fast-growing warm season crops can also be an excellent choice for a midsummer garden start. Think of it like unplanned succession planting ()!
Cucumber and Squash
Cucumber and summer squash can both work for a quick harvest before the end of the season. Select varieties with shorter days to harvest and you can pre-germinate your seeds or start seedlings inside a week or two before planting outside. Seedlings that are too large don’t transplant well, and direct sowing will typically make for hardier growth early on. If you do transplant seedlings you can use the approaches above for the leafy greens to ensure successful transplants.
Beans
Bush beans can be succession sowed throughout the season, or planted a second time in mid-summer for a fall harvest. Be sure to keep moisture consistent while the seeds germinate. You can soak bean seeds for 12-24 hours prior to planting to speed up the germination process.
This is by no means an exhaustive list of everything you can plant, but it’s a great start to increase the productivity of your garden. As always, if you have additional questions, you can reach out to your local Extension office.
As always, reach out to your local Extension office for further information if you have any questions.
Gardening in Colorado? Check out Grow & Give www.growandgivecolorado.org and in particular our Colorado Vegetable Guide https://growgive.extension.colostate.edu/colorado-vegetable-guide/ for more crop information on all of the above plants.
What if every gardener planted just one extra plant to share?
One small donation can have a tremendous impact. Just imagine, if every gardener planted one extra plant to share, collectively, we would have an abundant source of fresh, healthy produce available to be distributed to families experiencing food insecurity in our own communities! The free Fresh Food Connect mobile app connects you to a local hunger relief program, then manages and tracks your donations of homegrown produce throughout the season. Download the app today!