Grower's Guide: What to Grow in a Greenhouse All Year Long
Whether you want to extend your growing season for a few months or plant year-round, greenhouses provide the perfect environment for non-stop gardening. These useful structures also allow you to expand your plant options and grow what normally wouldn’t survive in your region. Read on to find out what to grow in a greenhouse all year long, get to know a few of our greenhouse options, and learn some efficient and rewarding tips to get you off to a better planting season.

Standard vs. Cold Frame Greenhouses

First and foremost, you need to understand what kind of greenhouse you’re working with. By understanding the capabilities of your structure, you can better provide the right environment for the plants you want to grow. Standard greenhouses provide a warm climate for growing heat-loving, tender plants or growing plants out of season. These structures are used to maintain an ideal temperature regardless of outdoor conditions.  Depending on location, many gardeners will start plants inside their greenhouse and then transport these plants to their garden once outdoor temperatures are more stable and ideal. However, certain regions may still experience dramatic temperature fluctuations even in the summer. In these cases, it may be better to keep plants inside the greenhouse for the entirety of the growing season. Cold frame greenhouses are a bit different from traditional greenhouses. These structures use solar energy and insulation to create a microclimate within your garden - perfect for starting seedlings or transitioning greenhouse plants prior to outdoor planting. Depending on the style you choose, use a cold frame to overwinter tender plants, keep planting soil warm, extend the season for cool-season vegetables, or directly sow seeds earlier in the spring. Cold frame greenhouses provide necessary shelter from wind and weather without overheating plants.You can learn more about these structures in this blog post.

GrowIT Greenhouse-in-a-Box

GrowIT High Arch Greenhouse

PRO TIP:Are you a gardening hobbyist or planting professional? Do you plant small crops or prefer to reap a large harvest? Whatever planting style you prefer, there are plenty of unique greenhouses that can help you accomplish your growing goals. Utilize large industrial options such as our High Tunnel Greenhouses or small backyard greenhouses (like the GrowIT Backyard Greenhouse) based on your needs.

What to Grow in a Greenhouse Throughout the Year

Different climates and seasons offer new options for planting – especially when you own a greenhouse! Here are a few greenhouse plant recommendations for the entire year.*

Winter to Early Spring

what to grow in your greenhouse At the beginning of the year, sow frost-tolerant plants such as spinach, cabbage, lettuce, and broccoli in your unheated greenhouse. These plants endure significantly lower temperatures and are able to be planted outdoors 3-4 weeks before your last frost date.  Utilize your greenhouse to plant them even earlier without frozen ground or exceptionally cold evenings stopping you. Once the evening lows are generally above 30 degrees, plants can be transplanted outdoors to the garden.


what to grow in a greenhouse Once the spring and “official” planting season arrives, you’re free to grow more tender plants in your greenhouse. These plants need a warmer and more controlled environment with at least 8 hours of sunlight in order to thrive. Sow tender plants such as melons, cucumbers, and squash indoors and transplant early in the summer if you’d like. Make sure these plants won’t be exposed to any frost before transplanting, as frost will kill them.

Summer to Late Summer

Transplant the previous seasons’ plants outdoors to make room for mid-summer crops inside your greenhouse. As external and internal greenhouse temperature’s peak, grow heat-loving plants such as eggplant, tomatoes, or hot pepper varieties. Alternatively, too much heat in your greenhouse is not always ideal for certain plants. An overheated greenhouse invites mold, mildew, and dries out plant soil. When applicable, consider including a vent kit in your structure to allow sufficient airflow in your greenhouse and keep plants comfortable even on the hottest summer days.


what to grow in a greenhouse As the summer heat declines and cool weather returns, utilize your greenhouse to finish off summer plants and begin your second crop of cool-season vegetables. Since the cool-season crops are the hardiest, you shouldn’t need to keep your greenhouse heated for these plants. A few extra options to try this time around include kale, snow peas, and turnips. Growth will be slow, but steady, with plenty of new crops to eat and enjoy just in time for the holidays.

Follow Our Grower's Guide Series for More Planting Tips and Tools

While this offered a brief overview of what to grow in a greenhouse throughout the year, you can easily customize plant options based on your location, level of expertise, or preferred foods! Follow our Grower’s Guide series for more gardening tips and tools to ensure successful planting year-round. Shop our entire selection of greenhouses, raised beds, and more for your ultimate gardening space.

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*These recommendations are based on average humid continental zones that experience mild to warm summers and cold winters. Some options may be more or less suitable for your plant hardiness zone.