Nine Vegetables that LOVE Greenhouses!

Greenhouses have long been a staple for gardeners. If you love having your own homegrown food, with a greenhouse, you can have a luscious garden all year round! In this article, we’ll be going over nine vegetables that are perfect for greenhouse growing and providing you with everything you need to know to yield the perfect harvest no matter what season it is!

Not all vegetables thrive in indoor conditions, so which ones do? Here are nine delicious vegetables that thrive in the greenhouse:

Peas

Artichoke
Broccoli
Cauliflower

Spinach
Cucumbers
Tomatoes

Bell Peppers
Okra

With the right set-up, method and growing conditions, you’ll be harvesting fresh, healthy vegetables in your greenhouse. We’ll go into more depth regarding each vegetable, so be sure to stick around if you want a lush greenhouse yield this growing season!

Vegetables that Grow Well in Greenhouses

There are dozens of vegetables that grow well in greenhouses. From the more exotic plants like ginseng and mushrooms to more common leafy greens and herbs, the possibilities for greenhouse gardening are pretty vast.

However, the top nine vegetables we’re going to cover are the varieties that tend to grow best and can withstand all-year plantings. Once you master this list, you might make space for some other greenhouse favorites like basil, parsley, sage, leeks, onions, cilantro, leeks, and carrots.

Now, without further ado, let’s get into our top nine vegetables that love greenhouses!

1. Peas

While peas are most commonly planted in an outdoor garden for a bigger harvest, with a large greenhouse, you may be able to collect a decent amount of peas if you dedicate enough space to them. Peas grow best during cool seasons.

They’ll do well in early spring, and you can also get another harvest if you plant again in September, making it a wonderful crop for a winter greenhouse garden.

Though there is quite a variety of peas, the best for greenhouse growing are snap peas and snow peas. Both snow and snap peas have similar growing requirements and prefer soil that is moist but well-drained, as too wet of soil may result in rot.

Following are the steps to grow peas in a greenhouse:

Establish your peas in a germination tray by filling the tray with a preferably organic and nutritious potting soil.

Our favorite germination trays are these 72-celled trays (on Amazon), perfect for seeds and seedlings and large enough for roots to grow quite deep until they can be transferred into their final pot.

Paired with the Burpee Organic Premium Growing Mix (see on Amazon), you can expect your pea plants to grow in no time. This growing mix is made for containers and raised gardens and contains plant food that slowly releases and nurtures for three months. And if you’re concerned about quality, this potting mix is OMRI listed, meaning it’s certified for organic use.

Plant each of your pea seeds 1-inch deep into the soil.
Lightly mist with a spray bottle until the soil is dampened. Keep the soil moist at all times but allow the soil to drain after each watering to avoid overwatering.

Test the temperature of the soil daily to ensure that it is at least 40 degrees Fahrenheit in order for the pea seeds to germinate.

Once the seeds have germinated, the greenhouse should be 75 degrees. Alternatively, you can set a soil heat mat underneath the cell germination tray to raise the temperatures.

Place a fluorescent light above the seedlings. A light like this one (available from Amazon) will work. Make sure it is more than 2 feet above the seedlings during the winter months.

Once the seedlings have grown 5 inches tall, transfer them into a 5-gallon container, leaving a 2-inch space between the rim of the container and the fresh potting soil.

To do this, loosen the roots, dig a hole only big enough for the root ball, and plant as normal and water until thoroughly moistened.

Use a 5-20-20 fertilizer every three or so months.

Place a trellis in the soil as your pea plants grow larger and wrap the vines around it to support the plant body.
Once the peas reach maturity, harvest them often, pinching them off as close to the branch as possible to encourage continuous reproduction.

Remember to plant enough pea seeds to last you and your family throughout the winter. You’re not going to want these sweet peas to end!

2. Artichoke

Whether or not artichokes are on the list of your favorite foods, it doesn’t change the fact that they grow well in greenhouse conditions.

Though they’re to be planted in late winter, and budded by the next fall, Artichoke plants cannot survive extended periods of cold spells. You’ll need to ensure that they’re in a warm greenhouse climate, watered enough, and fertilized extensively.

As with many vegetables, there is a variety of artichoke to choose from, mainly coming down to green and purple varieties.

For a green artichoke, we recommend going with the Green Globe artichoke. This variety produced a high volume of blooms annually and would be a great option for artichoke lovers.
For a purple variety, we recommend going with the Violetta for greenhouse planting. Violetta artichokes are especially hardy and may do exceptionally well in a greenhouse environment.

To grow greenhouse artichokes from seeds, you’ll need to follow these steps:

In your heated greenhouse, place each individual seed into a 4-inch container filled with a nutritious, organic soil and mist the soil until moist. Allow the water to drain thoroughly. In normal indoor temperatures, around 70 to 75 degrees Fahrenheit, you can expect your artichoke seeds to germinate within around a week.

Once the seeds have grown into established seedlings, it’s best to transfer them directly into the ground inside your greenhouse 3 or 4 weeks before the final frost. You’ll want to expose the plants to temperatures around 45 or 50 degrees to encourage future flowering. Alternatively, you can transfer the seedlings into larger containers. Be sure to plant the artichokes so that their crown meets the soil. Keep well-watered, but drained.

Because mature artichokes are so large, they require quite a large space to grow. Each artichoke plant should have at least 4 to 6 feet between one another when planted in the ground inside your greenhouse. Ensure that the ground inside your greenhouse is rich and fertilized before transferring your artichokes to the ground.

Artichokes require high amounts of Nitrogen, so an organic fertilizer, such as Dr. Earth’s Big Nitrogen Plant Food Concentrate (click link to see on Amazon), will work wonders in encouraging optimal growth and bloom yield.

Water often. Artichokes will need an inch to an inch and a half of water per week. Be sure that the ground or container they’re placed in drains well, as stagnant water will encourage mold and root rot.

In mid-to-late summer, harvest the developed artichoke buds (leaving around 3-5 inches of the stem) when the bottom row of scales begins to open. Each stem should produce around 3 to 5 blooms.

The key to growing artichokes indoors is avoiding frost temperatures, keeping the plants well fertilized with high-Nitrogen options, and ensuring that they have optimal space to grow to their full potential.

3. Broccoli

Broccoli is a vegetable-fan favorite and can be grown in quite large numbers in greenhouses, all year round. However, if you live in an area where temperature shifts are common, you’ll need to monitor the temperature to avoid killing off the plants on cold nights and heat your greenhouse if necessary.

Let’s go over growing greenhouse broccoli step-by-step:

You’ll need wooden crates that measure at the very least 3 feet ride per row and 2 feet deep. This will ensure that the plants have enough room for their roots and to flower without becoming overcrowded – overcrowding can lead to competition between plants, and ultimately die-off.

Fill each crate with organic, rich soil as full as possible without it spilling over.
Plant the broccoli seeds in the soil an inch down and about 20 inches apart from one another.

Gently mist the soil until damp.
Wait to water the seeds and seedlings until the soil feels dry to the touch. As the broccoli sprouts, avoid watering the heads of the broccoli and, instead, water at the base of the stem.

Broccoli plants will reach edible maturity in about 2 ½ and 3 ½ months. Once they’ve fully grown, snip off the broccoli, leaving about 5 inches of stem.

Overall, broccoli is a rather easy plant to grow inside a greenhouse, just as long as the temperatures don’t drop too low and stick around 70 or so degrees Fahrenheit.

4. Cauliflower

While most gardeners choose to start cauliflower seeds in containers, if you’re planting in a greenhouse and don’t want to plant directly in the ground, you can use wooden crates (similar to that of growing broccoli in) to grow cauliflower to maturity.

Because cauliflower and broccoli are related, the method for growing them in a greenhouse is rather similar. First, decide whether or not you want a fall or spring cauliflower crop. Then:

You’ll need to plant the seeds 12 weeks (for a fall crop) or 10 weeks (for a spring crop) before your area’s last frost. Fill nursery pots with organic soil, leaving ½ inch of space at the top.

Place four seeds in the middle of the pots, and cover them with soil, being careful not to pack the soil down too tightly.
Spritz gently with a fine mist, enough to dampen the soil, but not overwater.

Once the seeds become 2-inch-tall seedlings, transfer each plant into their own container or plant in a wooden container 3 feet wide per row and 2 feet deep, placing each plant around 20-25 inches apart. Ensure that the seedlings receive 6-8 hours of sunlight per day or place under a plant light.

Once every month, feed the cauliflower with fertilizer and keep the soil moistened, but not overly wet.

Harvest the cauliflower once the head is between 6 and 8 inches across. Cut the stem low enough to leave a row of leaves.

Like broccoli, you’ll want to avoid allowing cold temperature shifts to frostbite cauliflower. Place the cauliflower plants under a heated light or be sure that your greenhouse is properly heated to an average indoor temperature. Fertilize with a water-soluble fertilizer, keep the soil moist and well-drained, and allow enough space between plants to avoid overcrowding.

5. Spinach

Leafy greens such as spinach are highly nutritious and should be a staple in a healthy diet. Believe it or not, spinach is actually a traditional greenhouse plant because it grows so well and is extremely easy to establish.

The same plant can be harvested many times throughout the year, and spinach doesn’t require constant high temperatures like some of the other vegetables on our list.

You can either plant in a wooden crate, with the dimensions listed in the previous two vegetable sections, or you can plant directly in the ground of your greenhouse.

To grow these powerhouse vegetables, follow these steps:

A week before planting in the ground, till the soil and desired nutrients. Alternatively, add a rich, organic soil to your wooden crate all the way to the edge without spilling over.

Start the seeds either in a cell germinating pot (transferring to the ground three weeks to a month after they become seedlings) or plant the seeds directly in the wooden crate, spacing them out around 5 inches apart.
The temperature should be around 70 to 75 degrees Fahrenheit in order for the seeds to germinate. Avoid too cold of temperatures or drastic temperature fluctuation.

Spinach plants require quite a bit of watering and should receive around 2 inches of water each week. Allow the water to drain completely.

Spinach can grow in sunny or partial shade. Be sure to place your plants under a fluorescent light or in a spot in the greenhouse that receives adequate sun during the day.

Harvesting should occur in about 40 to 45 days when the leaves reach maturity. Pluck the leaves as soon as they are mature. If you wait too long, they will become bitter.

In general, spinach is one of the simplest-to-grow vegetables that love greenhouses. Aside from nutrient-rich soil, stable indoor temperatures above freezing, and optimal watering and sunlight, spinach plants don’t have special requirements to flourish and won’t need to be babysat.

Overall, they’re a great option for greenhouse gardening and will make a delicious and healthy addition to your homegrown meals.

6. Cucumbers

For greenhouses on the smaller size, this is one vegetable that can grow well no matter the space you have set aside for it (thanks to its vine-loving disposition). They also grow pretty rapidly, so you won’t have to wait too long to enjoy them!

Follow these steps to grow greenhouse cucumbers:

Start this process 3 weeks before the last frost date so that they are established plants after the cold weather subsides (cucumbers are extremely susceptible to damage from the cold).

Alternatively, heat your greenhouse to 70-75 degrees Fahrenheit so that you can plant any time of the year. Each seed should be planted 12 to 15 inches apart.
Start with a large, raised wooden bed, about 6’x6’.

Fill with a rich, organic soil up to near the top edge of the crate.

Place a trellis to the side or behind each cucumber plant, and, as they start to grow, gently guide the stems up the trellis so that they’re wrapped around neatly. This added space will encourage more flowering and growth.
Once the cucumbers are sprouted plants, they will require a gallon of water every two weeks. Or, you can water “very little, very often,” keeping the soil damp and not allowing it to dry.

Cucumbers need adequate sunlight. Place your cucumber containers in an area of your greenhouse that receives at least 6 hours of sunlight each day.

After about 12 weeks of growth, you can harvest your cucumbers (when they’re around 6 to 8 inches long).

Don’t wait too long to harvest, as the longer they sit on the vine, the more bitter the taste becomes. Each plant can produce between 20 and 50 individual cucumbers with frequent harvesting.

Frequent watering, rich soil, warm temperatures, and a trellis that can sustain the weight of the cucumber plants as they grow is practically all there is to growing these delectable vegetables in your greenhouse all year round.

7. Tomatoes

A garden favorite and a delicacy in homegrown dishes, tomatoes can practically be grown anywhere — indoors, in hanging baskets, upside down, on trellis’, and yes, in greenhouses.

Planting tomatoes in greenhouses is virtually the same method as in the garden, especially if you select a variety marked as a greenhouse plant.

Here’s how you can grow your tomatoes inside a greenhouse:

Set your greenhouse to an average daytime temperature of 70 to 80 degrees Fahrenheit and a night temperature of 60 to 65 degrees Fahrenheit. Tomatoes don’t last in freezing temperatures and prefer warmth.

Fill a starting tray with organic, sterile soil.

Place a single seed in each cell in the tray about ¼ inch deep into the soil and lightly cover, taking care not to press or pack down tightly.

Water with a mist until the dirt is damp. Allow the water to drain. Repeat whenever the soil appears to be drying slightly.

Keep the seeds in a partly sunny area of the greenhouse or in your home until they have sprouted. The temperature should remain between 75 and 80 degrees. Once they’ve sprouted (between 1 and 2 weeks), you may move them into the greenhouse or move them to a sunnier spot inside the greenhouse.

A couple of weeks after your tomato plants have sprouted, transfer them into small pots.

Once they’ve grown 4 to 6 inches tall, transfer them again — this time, into their final, large growing pot. Each plant should have 4 square feet of floor space to spread out and encourage airflow.

Add a fertilizer that is high in Nitrogen and Potassium to the final growing pot.

As your tomato plants grow, tie them with twine to a stake to keep their stems straightened. Also, add a trellis behind the plants so that their vines can wrap around them and grow outwards, keeping the vegetables off of the greenhouse floor.
Help your tomato plants pollinate by placing fans near them when their flowers are fully bloomed.

Harvest the tomatoes once they are fully red and plump. Alternatively, you can pick them when they are 70 to 80% red (or even green), depending on what you plan on using them for.

The greener the tomato, the more bitter and harder they are — the redder, the juicier and sweeter.

Aside from the method of growth we’ve described, you can also place seedlings in hanging baskets, allowing the tomato plants to grow downward if you lack the space for large pots inside your greenhouse.

8. Bell Peppers

In reality, you can grow virtually any pepper you like in your greenhouse, mainly because all pepper varieties love the heat, and a greenhouse can provide that environment for them without the fluctuating temperatures that may be found outside.

However, because bell peppers are such a favorite among gardeners, we’ll be discussing how to grow them in your greenhouse. Inside the greenhouse, the yield of the harvest and the quality of bell peppers are often better than when they’re grown in a garden outdoors (imagine that!).

To grow bell peppers in your greenhouse garden, follow these steps:

In a germination tray, place a rich, well-drained organic soil that contains high levels of phosphorus and calcium. Sow seeds in the soil as directed.

The soil temperature should remain between 80 and 90 degrees Fahrenheit for proper germination. This can be achieved with a heat mat.

Once the plants become leafy seedlings, transplant them into a larger pot (2 or more inches). At this time, temperatures can be lowered to around 73 degrees during the day and 70 at night.

A week or two after you’ve transplanted the seedlings, lower the greenhouse temperatures around 65 degrees Fahrenheit at night and keep the daytime temperature at around 74 or 75 degrees. Do not allow the temperature to fall below 61 degrees.

As the bell pepper plant begins to grow larger and produce blooms and fruit, place a trellis behind it and tie the stem (loosely) to the trellis. This will keep the plant growing upright and the stems branching out in the direction you want — that is, upwards, and away from other plants that may be nearby.

Once the peppers have reached full size and color, you may harvest the plant.

Keep in mind that you may need to prune any stems, flowers, leaves, or even peppers that look unhealthy. Forgetting to do so may negatively affect the rest of the bell pepper plant. Watch for signs of disease and pests (though you may not have to worry too much about insects inside the greenhouse).

9. Okra

Our final vegetable that loves greenhouses is the okra plant. Native to the southern United States, these plants thrive in warm conditions — and it’s relatively easy to grow! These pod-like vegetables are a staple in southern meals and are delicious when fried or added in dishes like gumbo.

In order to grow okra from seeds in your greenhouse, follow these steps:

Soak the seeds for 12 to 18 hours to soften their thick outer shell.

After soaking, plant seeds in the well-fertilized soil 3 to 4 weeks before the final frost of your area.

Keep the soil well-drained and make sure the temperature is 65 to 70 degrees. These plants will grow tall, so be sure to plant them in an area where other sun-loving plants are not — plant in full sun or part shade.

Water the okra seeds and seedlings. Okra requires about an inch of water each week. As the plants grow, water at the base of the stem, avoiding the leaves. Dampened leaves can encourage fungi growth.

Your okra will be ready to harvest in about 2 months. When you see that the pods are around 3 inches long, you can cut the stems right above the crown. Watch out for the leaves, as they can be irritating to the skin. Wear gloves to avoid scratches or cuts.

Okra plants produce quite a large amount of okra pods. Once you pick one pod, another will begin to grow in its place. Pick the okra every other day to avoid them growing too long and getting too hard to eat.

Wrap Up

Now, hopefully you are ready to grab some seeds and get them started in your greenhouse. Once you know the slight variations needed for each type of plant, you’ll start to get a feel for all of these greenhouse-loving varieties. Enjoy those fresh veggies all year long!

Gardens are not made by singing ‘Oh, how beautiful,’ and sitting in the shade. –Rudyard Kipling, ‘The Glory of the Garden‘ (1911)