Greenhouse Gardening: How to Extend Your Growing Season

Let’s take a quick poll: Do you find yourself uncomfortable with the word “greenhouse”?

If you’re a budding gardener, you might be under the impression that greenhouses are reserved for expert horticulturalists — those who approach gardening as a way of life and not just a kitchen window hobby. Perhaps you’re even a little intimidated by the idea of growing in a greenhouse.

But the fortunate reality is that anyone can learn to use a greenhouse to extend the growing season. And with this beginner’s guide, we aim to help you do just that.

Benefits of Greenhouse Gardening

Commonly used in controlled-environment agriculture (CEA), greenhouses keep plants cozy and comfortable — even when temperatures outside drop below freezing. As a result, greenhouse gardening offers many advantages of indoor gardening (namely fresh, healthy produce regardless of climate, season, or weather) while circumventing potential challenges, such as curious pets or a lack of indoor space.

Plus, because greenhouses use the sun to nurture plants, you don’t need a lighting system as you do for an indoor garden (provided your greenhouse is exposed to 6–8 hours of direct sun per day).

Tower Tip: With a proper cooling setup, greenhouses can also help you keep crops happy in extremely hot weather.

How Much Does a Greenhouse Cost?

The cost of a greenhouse usually depends on how big it is and what it’s made of (e.g., plastic vs. glass). If you’re looking only to protect a few plants or a single Tower Garden, you can find small, tent-like structures at most home and garden stores for as low as $30.

Or if you’re feeling thrifty and crafty, you may be able to DIY a greenhouse using materials you already have on-hand. For example, these creative Tower Gardeners used plastic wrap and spare fencing.

On the opposite end of the cost spectrum are custom-built greenhouses, which often require the help of an architect and contractor. But if you’re committed to your garden and want a tailored design, that may be an approach worth considering. (For inspiration, check out these neat greenhouse Tower Farms.)

How to Grow a Successful Greenhouse Garden in 3 Steps

Ready to try your hand at greenhouse gardening? For a successful experience, keep these best practices in mind.

1. Monitor the temperature.

Most plants grow best in a temperature range of 65–75˚F. So watching the thermometer in your greenhouse is critical — especially in cold weather. You can use a small space heater to warm your greenhouse, as necessary. (If you find the temperature doesn’t seem to improve, inspect your greenhouse for openings that may be allowing cold air to creep inside.)

In the event that your greenhouse gets too hot, open the vents if your greenhouse has them, run a fan, or simply leave the door open to improve air circulation.

2. Scout for plant diseases and pests.

Because a greenhouse is an enclosed space, it’s common for humidity levels to increase as plants transpire (i.e., release moisture into the air). And where there’s high humidity, there’s often fungus.

Check your plants weekly for signs of disease to catch problems early while they’re still easy to remedy. Running a fan and regularly cleaning and pruning are simple ways to keep the air flowing and prevent issues in the first place.

As you’re scouting for plant diseases, remember to also look for any unwanted visitors. In the absence of natural predators, aphids, thrips, and other bad bugs can quickly infest a greenhouse. (If you do have pest trouble, here are a few tips on what to do.)

3. Hand-pollinate fruit-bearing plants (if necessary).

During cooler months, bees are rare, especially in a greenhouse. So you’ll probably have to hand-pollinate your fruit-bearing plants — such as tomatoes and peppers — to ensure healthy yields.

Alternatively, you can stick with indoor-friendly plants that don’t produce fruit, such as:

  • Kale
  • Spinach
  • Arugula
  • Lettuce
  • Mustard greens
  • Swiss Chard
  • Leafy herbs (e.g., basil, cilantro, dill, mint, oregano, thyme)

Tower Tip: Learn how to grow these and other crops in the free Tower Garden Growing Guides »

Over to You

We hope this guide has given you the knowledge and confidence you need to start your own greenhouse garden. (Because there’s nothing like fresh, homegrown produce in the dead of winter!)

If you have any questions or tips of your own, we’d love to hear from you in the comments below.

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