Greenhouse Tips & Advice

Using a greenhouse is a great way to extend your growing season for your garden or nursery. You can also grow year-round in a greenhouse, or grow plants that normally wouldn't thrive in the cold of Utah and Idaho. For whatever reason you want a greenhouse, there are several things you should know about before getting started.

Terms to Know

Sidewall - This is the straight side of the greenhouse. The length of this part dictates your "Sidewall Height".

Endwall - This is the back or front framing of the structure and can be wood or metal.

Ventilation - Ventilation systems can be passive, such as roll up curtains on the sides of the greenhouse, or they can be mechanical with powered fans that push air throughout the greenhouse.

Shutters - Intake shutters open up to allow air to flow through the structure.

Coverings - can be several different materials used to protect the plants. Generally they will be made out of a poly material and coated to protect from UV degradation.

Setting Up Your Greenhouse

Growing plants in a greenhouse is a little different than traditional growing outdoors. The sun will still provide light and some heat, but you will need to give your plants everything else they need such as moisture and nutrients. You will also be responsible for controlling the temperature for your plants. 

To get started with your greenhouse, you will want to decide how much growing space you need. Once you know the size you want, you will want to decide between an attached greenhouse - leaning against an existing wall such as your garage - or a freestanding greenhouse built completely on its own.

It is important to decide what material you would like to use for your greenhouse. The most common materials are glass (the most expensive), plastic sheeting (cheap but won't last long), or polycarbonate panels (strong, affordable, retains heat well). We recommend sturdy polycarbonate panel greenhouses for most applications. Use H Profile and U Profile panels to combine panels together during installation. You will cover the top edges with aluminum tape and the bottom edges with vent tape. If you want to make a plastic sheeting greenhouse we recommend using Tuff Lite plastic and holding the greenhouse together with a solid base and wiggle wire. You can use poly patch to fix tears and holes. 

Choosing a site is also an important aspect in greenhouse design. You will want it nearby your home so it is easy to access. Also, consider access to water and electricity which you will probably need. Find a location with good sun exposure, preferably with at least 6 hours of direct sunlight per day in the winter. 

Just like in your garden, having good soil is crucial. Be sure to use a high quality bagged soil that drains well. A lighter weight potting soil will allow the plant roots better access to air. Fertilizer is even more important in a greenhouse since there are no natural nutrients there. We suggest Fertilome 20-20-20 water soluble fertilizer.

Regularly inspecting your greenhouse and plants will be the best method to ensure a healthy growing environment. Keep an eye on the temperature, pests, soil, and of course, the plants themselves to make sure you have a good crop. 

Environmental Control

Heating. Insulation is critical to keeping your plants warm if you live in a cold climate. While a lot of sun will come in during the day heating the plants, an uninsulated greenhouse will cool off quickly at night making a heating system required. 

Shading. If you keep plants during the summer months, or have lots of direct sunlight, shading will be necessary to keep plants from getting burned. Shade cloths, vinyl plastic shading, or paint-on materials can all be used to shade plants. We recommend, shade cloths or black mesh tarps as a great option for keeping your plants cool in warmer weather.

Ventilation. Plants can overheat even during cool weather, so good greenhouse ventilation is crucial. Vents can be manually opened or you can use automatic vents to control the temperature of your greenhouse. You can also install an oscillating fan to keep air moving through the greenhouse and prevent many disease problems.

Pests. Avoid pests in your greenhouse by installing insect screens, and keeping your gardening tools clean. Check plants before bringing them into the greenhouse carefully to be sure they are bug and disease-free. Immediately remove any plants with bugs or diseases. Using insect control granules is also recommended.

When to Plant

With a greenhouse, you can start plants just about whenever you want. However, there are different plants that you may want to plant in different seasons. If you have questions about when or what plants to grow in your greenhouse, give us a call at 801-268-4500 and one of our gardening specialists can help you out!