Greenhouses 101 – Grow Year Round!

Greenhouse tips
Photo by Annie Spratt

Having fresh fruits, vegetables and herbs available throughout the year is very convenient. It results in less gas needed to run to the store and less garbage created. These are just a few of the advantages of having your own greenhouse. You also have the ability to control temperature, humidity, and watering and the controlled environment allows better pest control. In this guide, we’ll discuss how to set up your own greenhouse and what types of crops to grow in it.

Building a Hobby Greenhouse


Depending on your skills, you may want to build your greenhouse from scratch, buy a kit or have someone build it for you. For outdoor greenhouses, you may need to obtain a building permit. Check with your local government to determine if there are any zoning laws that you need to consider.

Outdoor greenhouse kits are available for a variety of sizes and materials. They range from very affordable basic frames with plastic covers to larger, permanent structures features like polycarbonate glazing.

If you only need to grow small quantities of plants in the winter, you may want to consider an indoor mini-greenhouse. These can be assembled quickly and can be used where space is limited. If you have very limited space available, you can also consider an indoor hydroponic kit as an alternative to a greenhouse.

At the low-cost extreme, you can find instructional videos like the one below that describe how to build a DIY greenhouse for under $20.

If you are more ambitious, the following video shows how to build a larger, low-cost wood-framed structure from scratch.

Starting out small may be your best advantage if you have any concerns about how successful this project will turn out. You can always go bigger the next year once you feel more comfortable with what is expected. Whatever happens, you will be rewarded with fresh fruits and vegetables that will feed you and your family all year long.

Other Greenhouse Components

The kits discussed earlier provide the frame and glazing materials for a DIY greenhouse, but other components are typically required.

Heat source

During harsh winters you might need a heating system to prevent freezing temperatures in your greenhouse and to keep your environment at the same temperature throughout the year. Also see our tips for heating your greenhouse in the winter.


You will also need a cooling and venting system to keep things flowing evenly and prevent plants from being overheated or burned.

Watering system

You may choose to have an automatic watering system because your plants will need watering frequently. Sprayers to help the humidity are also needed.


If you want to grow throughout the winter, you might want to install extra lighting because the daylight might be insufficient according to where you are located.

Fresh pots, soil, fertilizers, pest control, seeds, and/or seedlings are all a part of getting things started. This list can become bigger or smaller depending on the size and type of greenhouse you choose.

If you like electronic projects, creating your own greenhouse control components can be a fun and educational experience. Here’s a video describing how to make a greenhouse lighting system using variety of electrical components.

Tips on Heating Your Greenhouse This Winter

greenhouse in snow

In most parts of the country, you’ll need to heat up your greenhouse during the colder winter months. Greenhouse heating protects your plants from the frost while keeping them warm until spring arrives. However, this process may be expensive. That’s why we compiled a list of ways to limit heating of your greenhouse in the winter that are both cost-effective and efficient.

Insulate with bubble wrap

Start out by insulating your greenhouse with bubble wrap. By attaching a layer of bubble wrap to the inside of your greenhouse frame, you will reduce heat loss and block out icy winter draughts. We recommend that you buy purpose made horticultural bubble wrap insulation because it’s toughened and UV stabilized. These are usually found in garden centers.  Also, keep in mind that wraps made up of larger bubbles let in more light, which means extra heat.

Invest in heating

As we mentioned earlier, consider invest in a greenhouse heating system. If you happen to have a power line running through your greenhouse, then electric fan heaters are your best option. If not, we suggest you go with a paraffin heater.  Fan heaters are great for moving air around the room, preventing cold spots and reducing the risk of disease. They should be utilized in an open, central spot at one end of the building. Leave it as far away as possible from any area that comes into contact with water.

A reliable thermostat will save you money and energy because you’ll only be heating the greenhouse when necessary. Most electric greenhouse heaters are made with a built-in thermostat. This allows you to set the heater to turn on solely when the temperature drops to a certain degree. Find out the exact temperature your plants need to survive and keep it at that.

Use compost for heating seedlings

It can be a bit challenging to do it right, but it is possible to use compost to heat seedlings. The compost generates heat itself, but combined with sunlight it creates a great microclimate for encouraging seeds to grow in the winter.


Unfortunately, heating your greenhouse does typically increase humidity. To combat this issue, ventilate the building. Good ventilation is crucial for stopping the spread of fungal diseases and maintaining a healthy growing environment. Get rid of any condensation that forms by opening the greenhouse’s vents early in the morning. Then, make sure to close them before the sun goes down. This is so the vents can trap the daytime heat, keeping the greenhouse warmer for longer.

Also watch for unintended ventilation (air gaps) that will leak heat from the greenhouse and allow windy drafts during colder weather. Use a caulking material to patch any places where cold air can enter.

The 15 best crops to grow in your greenhouse

Greenhouse Vegetables
Photo by Alexandr Podvalny

Greenhouses are probably one of the best ways to grow fruits and veggies, as you have control over the environment. Here is a list of the 15 best crops to grow in your greenhouse.

  1. Kale is one of the easiest plants to grow as it survives the cold weather and grows steadily for months. Then you can even plant Kale again a second time in the same year and it will have a completely different taste!
  2. Beets are ideal to grow because they grow so fast! In about 60 days, a beet will grow 1.5 inches in diameter, which is perfect for cooking. It will then rapidly increase in size, as long as they have plenty of room to grow. These are a greenhouse must have.
  3. Peas are great to grow during the colder weather. The strive in winter greenhouses, as long as they have at least six hours of sunlight and moist, not soggy, soil.
  4. Radishes. To grow radishes successfully, you need to plant it in fertile and well-drained soil.
  5. Cucumbers thrive in greenhouses. You’ll want to plant in warm and humid conditions, being at least 60 degrees Fahrenheit and space them about 18″ (45 cm) apart.
  6. Tomatoes. Growing tomatoes inside increases your tomato production and the length of time they can be produced. You’ll need to keep tomato plants under 3-4 fluorescent lights for about 20-24 hours a day and in warm temperatures.
  7. Peppers need to be in warm and moist temperatures, in order to germinate and break dormancy. You want to maintain temperatures of 70 degrees Fahrenheit during the day and no lower than 60 degrees Fahrenheit at night.
  8. Cilantro is usually able to endure cooler temperatures, until about zero degrees. Therefore, Cilantro would be a great addition to your greenhouse, as long as it gets plenty of light.
  9. Watercress. Not many people believe that you can grow watercress in a greenhouse. But the truth is, it grows better in greenhouses because it grows faster under glass.
  10. Squash can grow year round, as long as it is in the right environment. Squash does best in warm soil, making a greenhouse an ideal climate.
  11. Swiss chard or rhubarb grows from early spring to late fall, making it a greenhouse must. Plus it is almost impossible to kill, so it is good for any new gardener.
  12. Melons are a great fruit to grow in your greenhouse. They have the ability to endure cold weather, so greenhouses make them even better!
  13. Oranges, like melons, also have the ability to endure cold weather, so these are a must-have in your greenhouse!
  14. Lemons sustain the freezing cold better than most other fruits or vegetables. These will be something you grow in your greenhouse year after year.
  15. Strawberries are very easy to grow in a greenhouse, and you can plant whatever kind you like, just make sure they get enough ventilation and space to grow.