A Field Guide to Greenhouse Gardening
Extend your growing season by gardening in a greenhouse. Greenhouse gardening offers many benefits, from letting you grow plants that wouldn't ordinarily survive in your area to starting your garden early and continuing to grow plants long after the first frost.
Although you can grow pretty much any type of plant in a greenhouse, where you put your structure and how it's heated and cooled makes a big difference. Learn all about greenhouse gardening by taking a look at the numerous articles we have on the topic.
One of the most important benefits of greenhouse gardening is that the practice lets you extend the gardening season. You can get a jumpstart on plants in the spring, when it is still too cold to put them outside. You can also continue to grow plants in the fall and winter, after temperatures outside have fallen too low to sustain most plants.
In the video, gardener P. Allen Smith introduces us to his greenhouse and shares some of the many benefits he enjoys because of it. For example, he gets a head start on tomatoes in the season. He can also start more unusual plants in the his greenhouse and can get an early start on seeds.
Greenhouse gardening also lets you grow plants that ordinarily wouldn't do well in your area. For example, gardeners in northern areas can try to plant citrus trees such as lemon and orange trees in their greenhouses. Some gardeners grow other types of exotic tropical plants in their greenhouses.
The greenhouse also provides protection to plants that might be too delicate to thrive under certain conditions. It provides shelter against rough winds and unpleasant weather conditions such as hail or snow.
Here's a great visual summary of the many awesome benefits of greenhouse gardening from Old Fields.
Although greenhouse grown plants often have their own slate of diseases, growing a greenhouse provides an extra layer of protection against common garden pests and certain soilborne diseases.
WHAT CAN YOU GROW?
What can you grow in your greenhouse? A better question might be, what can't you grow? As the Royal Horticultural Society notes, a greenhouse is a great space for growing vegetables.
You're able to extend the season of warm-weather crops such as eggplant, tomatoes and cucumbers from the early spring into the later fall in a greenhouse. You can start cold-hardy plants such as kale and peas earlier in a greenhouse. And your greenhouse can provide protection to tender plants such as salad greens in the heat of summer.
The video from California Gardener compares tomatoes plants that were started in a greenhouse to plants started in the ground, at the same time. The greenhouse grown tomatoes are considerably healthier and bigger compared to the ones grown in the ground.
Your greenhouse can be an ideal spot for growing flowers. According to Johnny's Select Seeds, the wind protection a greenhouse provides can make it a perfect spot for growing taller flowers such as delphiniums and snapdragons.
When choosing plants for your greenhouse, it helps to pick varieties that are either cultivated for growing in a greenhouse or that are known to perform well in an enclosed setting.
For example, some plants require pollination from a bee or butterfly to produce fruits. Since there aren't any butterflies or bees buzzing around a greenhouse, those plants won't do so well in that setting.
Cucumbers usually need bees to produce fruit. But parthenocarpic varieties of cucumber will self-pollinate. Those are the type you want growing in your greenhouse.
WHERE TO PUT IT
According to Burpee, one of the most important things to consider when greenhouse gardening is the location of the greenhouse. You don't want to put the greenhouse just anywhere.
It needs a spot that gets an adequate amount of light year-round. The location should also provide easy access to water and to electricity, to power the heater, if needed. Here are some more details from MonkeySee:
A greenhouse that has southern exposure will get the greatest amount of sunlight throughout the year, even in the winter when light levels are low. To make sure your greenhouse gets the sun it needs, it's important to avoid putting it in an area where there is any sort of shade cover, such as tall trees or buildings.
You may want to build your greenhouse next to or attached to another structure, such as a garden shed or your home. Doing so provides the greenhouse with an extra level of support. The greenhouse can also take advantage of heat absorbed by and given off by the attached wall.
WHAT YOU NEED
To do its job well, a greenhouse needs three basic things: heat, light and ventilation. Heat can be supplied by an electric or gas heater. If you live in a warmer area, the heat created by the sun can be sufficient for keeping your greenhouse warm.
Here's a really great primer on how to choose the type of greenhouse that's best for your climate and available land.
It is possible for a greenhouse to get too hot, particularly in the middle of summer. Ventilation, such as windows or panels that open to let cool air in, is a must. A fan that creates a gentle breeze can also beneficial. In very warm areas, your greenhouse may need its own air conditioning system.
Although your greenhouse should get all the light it needs from the sun, there may be times when that light is too intense. Hanging semi-sheer curtains or panels from the roof of the greenhouse, which you can move to create shade during the day, might be essential.
What you plant and grow in a greenhouse depends on the time of year. For example, in the fall, many gardeners bring tender plants into the greenhouse from the outdoors, to protect those plants from winter's cold temperatures. Some gardeners start perennial plants from seed and begin growing tender salad greens in their greenhouses in the fall.
In the spring, the greenhouse gardeners usually start warm weather plants, such as tomatoes, early. A greenhouse gardener can start tomatoes and other tender plants weeks earlier, in January or February, compared to March or April.
If you're excited to jump in and try your hand at gardening in a greenhouse, we have a wealth of articles to get you started. For example, you might wonder about the science behind a greenhouse. Our article on how greenhouses work will provide the full details of what makes the structures an ideal spot to grow plants, no matter what the weather is doing outdoors.
Although you can purchase pre-made greenhouses, going the do-it-yourself route can be a more cost effective and enjoyable option. Our article on DIY greenhouses introduces you to the topic and provides plenty of details and instructions for making your own structure.
Perhaps you like the idea of gardening in a greenhouse, but aren't sure what to grow or aren't sure which type is the best structure for you. Don't worry, as we have an article full of greenhouse ideas. From being the best tomato grower on your block to growing lots of citrus, you'll find plenty of ways to make the most of your greenhouse.
One thing that might be keeping you from building or working in a greenhouse is the cost. Yes, greenhouses can be expensive, but for many gardeners, the chance to keep on gardening through the winter is worth the extra cost.
Our article on the cost of building a greenhouse will give you an idea of whether or not the project is one you can afford. It'll also help you see if there are ways to make a greenhouse on a budget.
If you're concerned about heating a greenhouse, and you should be if you're in a colder area, our article on heating greenhouses gives you a full rundown of all your heating options. In some areas, the heat created by the sun's rays is sufficient to keep a greenhouse warm and toasty. In colder areas, you might need a special space heater or heating mats to keep your plants warm and happy.
Whether you need to purchase an entire greenhouse, a heater or plastic to build your greenhouse, you want to be sure you're getting the best products for your money. We've got a number of product round-ups and guides to help you make informed purchasing decisions.
For example, in our round-up of greenhouse kits, we recommend a few of the best kits on the market and give you advice for choosing the right one for your particular situation.
Our round-up of the best greenhouse plastic available introduces you to the highest quality plastic available and explains the benefit of using greenhouse plastic over glass and other materials.
If your greenhouse does need a separate heater, you want to make sure you pick out the best one for your space and area. Our round-up of the best greenhouse heaters introduces you to the products that are available and provides tips on choosing the right one for your greenhouse.
Finally, our guides to purchasing a small greenhouse or a portable greenhouse are must-reads if you're planning on buying a pre-built structure.
Did you know?
As of 2017, the total vegetable production area for greenhouses worldwide is 1,208,874 acres.
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Photo released into the public domain.
Source for the greenhouse fact: Cuesta Roble Consulting.