Want to start growing vegetables in a greenhouse year-round?
Having control over some of your food supply is comforting, but knowing which vegetables grow best in a greenhouse is the first order of business to achieving a successful harvest.
Inside this guide, I explain the benefits of growing veggies in a greenhouse. I also detail the top vegetables that excel living under such conditions and the correct time to plant them, so you’ll be ready to start planning and planting!.
Best Vegetables to Grow in a Greenhouse
Under ideal conditions, you could technically grow any vegetable in any season within the confines of a greenhouse, but most gardeners like to follow the natural growing cycle of plants.
Having a constant rotation of crops in all cycles of growth is not only interesting but also fun and satisfying. You will have pride in your efforts as vegetables finish crop production all through the year.
Next, I list each season and which vegetables are best to plant during that time for optimal growth and harvest size.
Winter to Early Spring
- Cabbage and lettuce
Start the year by planting cold and frost-tolerant plants. You can choose to do this in a non-heated greenhouse if it provides enough protection from freezes.
Mid to Late Spring
Spring brings longer and warmer days with around eight hours of sunlight that these plants need to flourish. Many squash varieties require space for spreading foliage, so take that into consideration or try vertical gardening techniques.
Summer to Early Fall
- Peppers (hot or sweet)
- Herbs (all varieties)
These veggie plants can tolerate hotter conditions within your greenhouse but don’t allow them to cook. Good ventilation, along with proper humidity and watering, is key to preventing wilting. With good care, you can pull produce from these plants for several weeks.
- Snow peas
Greenhouses are fabulous in the fall, especially if you can provide supplemental lighting as the days shorten. Now you can plant vegetables that like cooler temperatures, and the bonus is that these varieties tend to be heartier and need less care.
Benefits of Greenhouse Vegetable Gardening
A well-built greenhouse with sturdy and solid cladding, venting, and lighting can provide the ultimate environment for growing vegetables all year long because of these benefits:
- Provides a longer growing season
- Maintains better climate control
- Offers protection from harsh weather conditions
- Allows for better pest and disease control
But even portable, or cold-frame, style greenhouses can provide enough protection to many crops that allow gardeners in many regions to grow abundant vegetables.
Let’s look at the differences in microclimate you can expect from different styles of greenhouses. Learn how you can use this knowledge to grow vegetables more victoriously.
Check Your Greenhouse Microclimate
How much heat your greenhouse retains is the most critical factor you need to consider when starting vegetable crops.
Solid-built, traditional greenhouses contain heat better than soft-side fabric or plastic ones can, which allows you more freedom to plant vegetables that require consistently warmer temperatures.
That doesn’t mean you can’t use a cold-frame greenhouse during the cold winter months. It just means you may need to provide supplemental heating to the space to keep your vegetables warm and happy.
I know of expert gardeners growing warm-weather veggies in the dead of winter by using heaters to keep their greenhouses above 62-degrees Fahrenheit.
I also have fellow greenhouse gardening friends who use vents and good air circulation to keep their greenhouse cool enough for more cool-growing crops like turnips or peas.
Micro-climates within your greenhouse space are also a factor to consider. Plants near the perimeter of the building will be cooler than central locations. The north greenhouse wall will provide more heat and light unless you have large trees outside that block out the sun.
Knowing how the seasons affect the lighting within your greenhouse plays a critical role in where and how you plant vegetables.
Daylight hours play a significant role in the growth cycle of all plants, signaling when to go dormant, flower, or produce seed or fruit.
Depending on your region and position of the greenhouse, you may need to provide grow lights during the shorter days of the year to keep your veggies growing strong.
Some regions of the country may offer too much light intensity during parts of the year, and shade cloth may be necessary to keep plants healthy.
Lastly, your region and style of a greenhouse play an integral part in how much humidity your structure holds.
Too little moisture and the plant’s soil dries quickly. Too much moisture and your plants can rot out or suffer from diseases.
Fans, outside vents, walls, doors, or windows that open can control high moisture conditions. Interior greenhouse air that is too dry can benefit from the addition of misters to the space.
Now that you know what you need to control growing conditions, it’s time to list the top vegetables that do well in a greenhouse.
Greenhouse Vegetable Growing Tips
1. Maximize your growing space
Go vertical with creeping or climbing vegetable plants. Use trellises or stakes for upwards growth, or try out hanging plants and letting the vines trail downwards.
2. Use a good soil medium
Vegetables do best in nutrient-rich soil that is light in texture for healthy root expansion. The soil mixture should also retain a fair amount of moisture to limit watering sessions.
I like using an equal mix of garden soil, peat moss, and compost which feeds the plants for the growing season without the need for much additional fertilizer.
Don’t forget to clean out pots and exchange soil when growing vegetables to reduce the chance of contamination entering new crops.
3. Reduce pests and disease issues
Allowing fresh airflow is an excellent way to deter diseases and pests from clinging to your plants. Don’t keep the greenhouse closed up all the time, which creates stagnant air. Use vents and fans regularly to increase fresh air circulation.
Full sunlight on plants is another way to discourage mildew, fungus, or mold from growing on the foliage. Move plants around if necessary, so all get time under full sun exposure each week.
Once your vegetable plants flower, some may need cross-pollination to bear fruit. If you don’t have an open greenhouse that allows in bees or other pollinators, use a self-pollinating tool to increase your vegetable production.
Growing vegetables in a greenhouse all year round is not hard when you know what to do and what issues to watch out for. Having delicious, fresh vegetables grown by hand is possibly some of the tastiest food you will ever eat.
I hope you find the helpful information in this guide useful when you start your greenhouse vegetable garden. By growing the right plants, you’ll be on your way to plenty of healthy vegetables for your dinner plate season after season!