First of all, you can grow any plant in a greenhouse, be it a legume, herb, spice, leafy green, flower, fruit, microgreen or root vegetable. If it can grow in a regular outdoor garden, it can grow in a greenhouse. As a matter of fact, the plant could do better in a greenhouse.
That’s the point, right? A greenhouse is supposed to:
- make gardening more productive
- create a controlled growing environment that protects plants from adverse weather, pests, diseases etc.
- allow a longer growing season and
- above all, do this for every plant.
So what does the term “best vegetables to grow in a greenhouse” mean? The answer is simple. It means vegetables that can maximise the full potential of a greenhouse. So, when you grow them in your greenhouse, you will enjoy a big harvest and other benefits. Here they are.
Broccoli
Leafy greens generally make good greenhouse vegetables. The broccoli is a fast-growing, easy-to-care-for, cool-weather leafy green that can grow year-round in a greenhouse.
However, the best time to grow is spring to late autumn. Make sure your broccoli plants get a good supply of sunlight.
Brussel sprout
The brussel sprout is also a cool-weather, easy-to-grow leafy green. You won’t have any trouble growing this vegetable in a greenhouse. Spring is the best time to start. However, you can still grow brussel sprouts in winter, especially inside a greenhouse.
Beans
The only issue with growing beans in a greenhouse is space. Bean plants need support structures like trellises for their vines to climb. These structures take up more of the already limited space inside a greenhouse.
However, you can go for bush bean varieties. They are more compact, so there is no need for support structures. Another option is to train the vines to grow upward.
You can plant beans in a greenhouse from mid-spring to autumn.
Cabbage
The cabbage is another leafy green that can grow year-round in a greenhouse. However, the ideal time to grow is spring to autumn. Whatever you do, ensure your cabbages get fertile soil, regular watering and enough sunlight.
Carrot
Here is another hardy vegetable that can grow in cooler months. In fact, the cold can actually make carrots sweeter. This is because winter carrots store more sugar to protect themselves from the cold.
Overwintering is also an option. With this, your carrots will lay dormant during winter and give early harvest in spring.
For a regular growing season, sow carrots from spring to summer. For winter carrots, you can sow in autumn or early winter.
Cucumber
The cucumber is also a good greenhouse vegetable. It is easy to care for and able to grow year-round. The only potential problem is space. Like beans, cucumbers need support structures for the vines to climb. Once again, fix this issue by choosing bush varieties or training the vines to grow upward.
Spring is the best time to sow. However, as stated earlier, you can grow cucumbers year-round in a greenhouse.
Eggplant
The aubergine, AKA the eggplant, is a warm-weather vegetable. It loves sunlight and warmth. Therefore, spring is the best time to grow. That gives your eggplants enough time to be ready to enjoy the summer. However, you can still grow in cooler months inside a greenhouse, especially if the greenhouse is heated.
For additional measures, you can mulch the growing medium and use stakes to support the weight of the fruits.
Kale
Kale is another hardy vegetable that can grow year-round in a greenhouse. It is also fast-growing and easy to grow. Spring is the best time to sow.
Lettuce
Lettuce is also fast-growing and easy to care for. Like kale, you can grow it year-round inside a greenhouse.
Melon
Melons also do well inside a greenhouse. In fact, it can be challenging to grow melon outdoors because of our weather here in Britain. So, a greenhouse is a perfect solution. Just make sure your melons get enough sunlight and warmth. Note that you will have to install support structures and help with pollination.
Spring is the best time to sow melons. This gives your plants time to be ready to enjoy the summer sun.
Onions
Onions also do well in greenhouses. They are compact and hardy enough to grow in cooler months. You can even grow into winter. However, spring and fall are the ideal times to sow.
Peas
Peas have a similar growth requirement to beans. So similar rules apply. You can start sowing in spring. Go for bush pea varieties or prepare to install trellises.
Peppers
Peppers love warmth and sunlight. Therefore, it’s best to sow them in spring or summer. However, you can grow in cooler months inside a greenhouse.
Tomatoes
The tomato is a staple of greenhouse gardening. Therefore, we hope you are not surprised to find it on this list. As a matter of fact, we recommend reading our article, “How to Grow Tomatoes In A Greenhouse”. It contains information that will be helpful for beginner and veteran greenhouse gardeners alike.
The tomato is a warm-weather crop. Therefore, the ideal time to sow is spring and summer, but you have more leeway when growing tomatoes in a greenhouse.
Tips for growing vegetables in a greenhouse
Here are some tips for getting the best result out of your greenhouse garden.
- Choose compact vegetables and varieties: Remember that a greenhouse has limited space.
- Use a good growing medium: Ensure the soil is fertile and well-drained. You can also replace it every 3 to 5 years. This will reduce the risk of infertile soil and the buildup of pests and diseases.
- Watch out for pests and diseases: You don’t want an infestation to develop inside your greenhouse. So stay alert and act quickly.
- Ensure your plants get enough sunlight: This will vary from one plant to another. So read up on your plant’s growth requirements. You can also move plants outdoors during warm months.
- Keep your greenhouse well-ventilated: You can achieve this by spacing plants properly, installing a ventilation system, and opening the vents and windows to let in hot air. Please, don’t leave windows open in cold months.
- Keep your greenhouse warm in winter: Start by keeping the windows, vents and doors closed. You can also install insulation or a heating system.
- Grow throughout the year if possible: This is why we have included both cool and warm-weather vegetables on this list. Take full advantage of your greenhouse.
- Grow strategically. For example, sow subsequently to ensure continuous harvests and use crop rotation to prevent the buildup of pests and diseases.
Conclusion
Please note that there are still many great greenhouse vegetables out there. This is not an exhaustive list. Our aims for this article are ease, variety and a longer (or even year-round) growing season. Hopefully, we have done enough to get you started.