Gardeners rejoice – greenhouses give you the opportunity to extend your growing season, nurture plants from seedlings, and grow plants not native to your area. Read on to learn everything you need to know to select the best greenhouse for your needs.
How Does a Greenhouse Work?
Greenhouses help provide consistent light and heat to help grow plants and improve production of produce. The materials of a greenhouse allow natural sunlight to penetrate the space and trap heat to keep the air inside warm and conducive to plant growth. Selecting an appropriate greenhouse for your needs helps you get the best results from your gardening.
Why Get a Greenhouse?
Greenhouses help gardeners accomplish different things depending on the type, materials, and usage. You can use your greenhouse to start plants from seedlings for a more successful yield, extend your growing season into colder (or warmer) weather, supplement your groceries by growing your own produce year round, or grow exotic plants that aren’t able to thrive in your region. Greenhouses help protect plants from insects, birds, and animals, and with large greenhouses, you can choose whether to grow plants in containers or in the ground depending on your needs.
Types of Greenhouses
There are a variety of greenhouse options available to suit any gardener’s needs. Small, portable greenhouses are perfect for starting seedlings early in the season for transplanting, while bigger projects such as growing fruit or maintaining a large variety of plants require a full-size greenhouse. Look for designs that can be modified if you think you may wish to expand your growing space in the future.
Greenhouses are either attached to your home or garage or a separate, freestanding structure in your yard. Attached greenhouses can often be less expensive as you’re not building all four walls, plus many gardeners appreciate the ability to tap into existing water and electricity. These styles can make your home too warm in the summer or require your home’s heating to work overtime in the winter by exposing your living space to more of the elements outdoors. Freestanding greenhouses often provide more space and allow in more light for plant growth.
Greenhouses are often classified by their average temperature. A hot house is kept between 65 and 70 degrees, which makes it ideal for growing tropical plants. These structures often need heaters and grow lights to maintain consistent temperatures. Warm greenhouses keep temperatures between 50 and 55 degrees to grow outdoor flowers and vegetables, and may also need lighting and heating for winter depending on your local climate. Cool greenhouses are great for germinating seeds and starting plants for the summer. They maintain a temperature of 40 to 45 degrees and do not need additional lighting or heat.
Panels and Glazing
Greenhouse panels come in three different varieties – clear, diffused, and semi-diffused. Clear panels let in the most light to help start seedlings. Diffused panels let in less light to help grow plants to maturity. For the most versatile greenhouse choose semi-diffused panels.
Panels can be made of a variety of materials. Glass may look beautiful, but can require a significant amount of work to ensure the greenhouse is well-sealed and can be subject to breaking easily. Since glass doesn’t diffuse light, it can also damage delicate plants. Fiberglass provides good insulation and is an ideal option for a starter greenhouse, but it may need to be replaced as the UV protection degrades. Polycarbonate is a durable option that comes in varying thicknesses to customize your insulation, making it great for year round gardening. Polyethlene film panels are inexpensive and great for starting seeds but degrade quickly and require replacement every few years.
The frame of your greenhouse supports paneling and needs to be sturdy and straight. Different materials are ideal for different designs. PVC pipe is an inexpensive material to frame your greenhouse and is best used for smaller designs along with metal supports to hold polyethelene film panels. Wood is strong enough to support glass and polycarbonate panels but can warp or rot over time, so select a type of wood known for resisting moisture and seal it every few years to ensure it lasts.
Aluminum frames are less susceptible to the elements but may require heavier gauge pieces to hold glass and polycarbonate panels. Galvanized steel is a strong framing material used with polyethelene film for more commercial style greenhouses which may not provide the curb appeal you wish for in a backyard design.
Insulation and Ventilation
Growing during the winter season in most areas requires insulation and multi-wall panel construction. For snowy areas, consider how precipitation will land on your greenhouse and how it will be removed to avoid damage and ensure light comes in appropriately. If you live in an area with milder winters or just wish to extend your growing season a little longer, less insulation may be more ideal.
Overheating plants is one of the most common reasons for plants to fail, so ventilation is necessary to release hot air during warm months. Vents can be at the top or base of the greenhouse and may be manual or solar-powered. Exhaust fans can also help ventilate your greenhouse in hot weather and shade cloths can help keep plants from getting burned in bright sunlight.
The first thing you’ll want to think about is where to place your greenhouse. Portable models can be set up on your patio or deck, while larger greenhouses should be placed on your lawn space in an area with maximum sun exposure. Most greenhouses don’t require a foundation, but you may wish to add some hard flooring to support any accessories inside the greenhouse. Ensure your greenhouse has adequate drainage and place a layer of landscaping cloth and gravel on the bottom to keep weeds out. Look at local laws and acquire any necessary permits before installation if necessary.
You’ll need to regularly monitor watering and temperature to ensure your plants grow to their fullest. You may need to invest in extra hardware to maintain proper conditions such as heaters, fans, or misters. Also consider if you need running water or additional lighting when deciding where to place your greenhouse.
Once you build your greenhouse, you can outfit it with a variety of accessories. Shelving options allow you to maximize growing space while vents, misting systems, lighting, and fans help maintain ideal growing conditions. You may wish to add a potting bench for additional workspace and tool storage or even seating to let you relax and enjoy your hard work.
Now that you’re ready to get growing, shop greenhouses and accessories to kick your gardening into full gear.