Key Takeaways

  • Cultivating vegetables in a greenhouse allows for an extended growing season and the ability to grow plants that prefer hot climates.
  • For successful tomato cultivation in a greenhouse, choose varieties like 'Vendor', 'Tropic', and 'Trust' that thrive in reduced light conditions.
  • Sweet peppers, leaf lettuce, cucumbers, beets, summer squash, carrots, and spinach are all great choices for greenhouse gardening.

A greenhouse is an excellent way to expand your garden and cultivate vegetables at home. Gardening in a greenhouse can kick-start your growing season earlier than your regional temperatures would typically permit.

Then, depending on your area and whether you install heating, it's also possible to continue gardening in the winter. Plus, with the ability to control temperatures, you can cultivate plants that prefer hot climates, even when your growing season is typically cooler.

The flexibility that greenhouses can provide is an asset! However, it's still essential to avoid common greenhouse mistakes and choose plants that thrive in greenhouses. Learn about eight scrumptious vegetables that flourish in greenhouses so you can enjoy a plentiful yield.

1. Tomatoes

Gardening pruning a tomato plant in a greenhouse

Fresh, ripe tomatoes are delectable. You can enjoy them right away after harvesting, store them for later by freezing them whole in a plastic bag, or cook them in a savory sauce. If you'd love to enjoy an abundant harvest of tomatoes, cultivating in a greenhouse is a great approach.

However, cultivar selection is essential for successfully growing tomatoes. Tomatoes love sunlight, and a greenhouse enclosure with a glass or plastic covering gets 20 percent less light than an outdoor garden. So look for greenhouse-friendly varieties like 'Vendor,' 'Tropic,' and 'Trust.'

For best results, ensure each plant has a 3 to 4-gallon container to provide adequate room. Fill the pot with pine bark compost. Then, to provide the warmth that tomatoes love, keep temperatures at 70 to 82 degrees Fahrenheit during the day and 62 to 64 degrees Fahrenheit at night.

2. Sweet Peppers

Sweet peppers are an excellent choice for a home greenhouse. Choose cultivars that adapt well to greenhouses, like 'Gourmet' with a vibrant orange hue, 'Corno di Toro,' which ripens to a vivid golden yellow or ruby red shade, and 'Topepo Rosso,' which is superb for grilling on the barbecue.

Maintain greenhouse temperatures between 59 and 86 degrees Fahrenheit for optimal growth. Cultivate each plant in a container at least 1 foot wide to offer plenty of space for your peppers. Then, don't forget to improve the soil by amending your potting soil with up to 50 percent organic compost or rotted manure.

3. Leaf Lettuce

One of the top benefits of gardening in a greenhouse is that it typically extends your growing season. With a greenhouse, you can grow leaf lettuce in the fall, winter, and spring, with temperatures below 70 degrees Fahrenheit during the day and above 45 degrees Fahrenheit overnight.

For best results, plant lettuce in a pot or container at least 4 inches deep and provide the plant with a potting mix containing a blend of soil and organic compost. If you cultivate in a 4-inch container, you can add up to 2 inches of compost. Look for green-house cultivars like 'Salad Bowl,' with striking lime-green foliage, 'New Red Fire' with brilliant burgundy shades, or 'Navara' with frilly maroon leaves.

4. Cucumbers

Cucumbers are another excellent contender for greenhouses. Encourage healthy growth by planting in pots that are a minimum of 8 inches deep. Then, cultivate one cucumber plant per 3 to 4 gallon container.

Cucumbers relish toasty temperatures in a greenhouse, so aim for a temperature range of 75 to 80 degrees Fahrenheit during the daytime and at least 50 degrees Fahrenheit at night. Cultivars like 'Marketmore,' with a crunchy sweet taste, petite green 'Mini Munch,' and crisp, refreshing 'Socrates' are all delightful options for a greenhouse.

5. Beets

Beets add a colorful splash of brilliance to a vegetable harvest. Beets flourish in a greenhouse when temperatures range between 45 degrees Fahrenheit in the evening to 70 degrees Fahrenheit during the day. Ideally, they prefer containers or growing bags with a depth of 8 inches and a well-draining potting mix that contains sand.

They are also cool-weather root vegetables, so they are a good choice for fall planting. When cultivating beets in a greenhouse, look for varieties like 'Bettolo' with deep maroon hues, 'Red Ace' with flavorful sweet roots, or cylindrical, oval beets like 'Forono.'

Make homemade potting soil with excellent drainage by combining equal parts sand, soil, and organic compost. Then, blend thoroughly using a trowel and fill your container.

6. Summer Squash

Enjoy a bumper crop of greenhouse summer squash when cultivating plants in spacious 8-inch deep containers that can hold 5 gallons of potting mix. Then, give your potting mix a boost by adding 1 to 2 inches of organic compost before planting.

Summer squash, like zucchini, flourish in warm conditions, so cultivate them in your greenhouse when temperatures fall from 55 to 85 degrees Fahrenheit. Choose varieties that adapt well to containers like 'Patio Star,' which is also an excellent choice for raised beds, 'Bambino' with a compact size perfect for greenhouse spaces, and 'Astia,' which produces shiny, green zucchini.

7. Carrots

Carrots are a unique option for greenhouse gardeners. Small, compact varieties like 'Scarlet Nantes' with classic orange shades, 'Adelaide,' which produces baby carrots at just 3 to 4 inches long, and 'Short n Sweet' with miniature 4-inch fiery orange carrots are best for greenhouse containers.

When cultivating carrots in a greenhouse, choose pots at least 12 inches deep and maintain cool temperatures between 45 and 70 degrees Fahrenheit. Then, improve soil quality by adding 1 inch of organic compost to loosen the soil, promoting proper growth.

8. Spinach

Spinach thrives in cool greenhouse climates, ideally between 45 and 50 degrees Fahrenheit. When you cultivate spinach in pots, it requires a depth of at least 8 inches. Then, mix equal parts of potting soil, organic compost or peat moss, and sand or vermiculite (a kind of clay) to create a nutritious soil that drains well. Encourage a high yield by picking cultivars that typically thrive in greenhouses, like bright leafy green 'Matador,' 'Medania,' with dramatic dark green foliage, or 'Renegade,' with smooth foliage in an oval shape.

Ready, Set, Grow!

Cultivating vegetables in a greenhouse is a rewarding way to level up your gardening expertise. Delicious greens like leaf lettuce and spinach, colorful produce like tomatoes and sweet peppers, and root vegetables like carrots and beets are all excellent choices. When picking the best vegetables to grow, watch for greenhouse-friendly cultivars, provide high-quality potting mix, and monitor temperatures.

What vegetables do you love growing in a greenhouse? Share your favorites in the comments below!