A greenhouse (As per Wikipedia) (also called a glasshouse, or, if with sufficient heating, a hothouse) is a structure with walls and roof made chiefly of transparent material, such as glass, in which plants requiring regulated climatic conditions are grown. These structures range in size from small sheds to industrial-sized buildings. A miniature greenhouse is known as a cold frame. The interior of a greenhouse exposed to sunlight becomes significantly warmer than the external temperature, protecting its contents in cold weather.
Many commercial glass greenhouses or hothouses are high tech production facilities for vegetables, flowers, or fruits. The glass greenhouses are filled with equipment, including screening installations, heating, cooling, lighting, and may be controlled by a computer to optimize conditions for plant growth. Different techniques are then used to evaluate the optimality-degrees and comfort ratio of greenhouse ate (i.e., air temperature, relative humidity, and vapor pressure deficit) to reduce production risk before the cultivation of a specific crop.
What To Grow In A Small Greenhouse
Mini greenhouses aren’t designed for every type of gardening task, but those things they’re good at are very handy indeed. Seed starting is one of the greatest strengths of mini-greenhouses, especially if you use one with a single shelf. Multiple shelf units must be placed in an ideal location to prevent shading of the seedlings you’re trying to grow. They’re also instrumental when you want to clone plants that are already in your landscape – the plastic covers will trap humidity, making it more likely that cutting or graft takes successfully.
These small structures require a great deal more care than a standard greenhouse since heat and high humidity can build rapidly. Monitor temperatures closely, especially if your mini greenhouse is outdoors and you need to watch the humidity level. Humidity is great for many plants, but it can lead to fungal disease and root rots as well. Plants for mini-greenhouses aren’t limited to full sun annuals or easy to start veggies. If you create the right microclimate inside your mini greenhouse, you can grow nearly anything. Annuals, vegetables, and fruits are only the beginning – as you get better at controlling conditions, try adding mini-greenhouses for orchids, cacti, or even carnivorous plants. Your efforts will be rewarded with gorgeous blooms that few growers ever get to experience.
What to grow in the greenhouse in summer
As summer’s temperatures climb, it can seem hopeless to grow anything inside the greenhouse. But with adequate ventilation, there are actually some excellent candidates for these conditions. If you think in terms of plants that like the heat—there really are quite a few, you’ll need to decide whether to plant them in containers—these should be sizeable if you choose this option (at least 2′ across for tomato plants)—or whether to create beds on the floor of the greenhouse. Either way, provide a soil depth of at least 12-18″ and plan to water at least once a day. Both fans and vents are absolutely necessary if you plan to grow summer crops; make certain that your systems are in good repair.
In fact, most members of the Solanaceae family, Tomatoes and peppers, originate in the warmer regions of South America, where temperatures seasonally climb well above 85 degrees. They’ll enjoy your greenhouse interior, and depending on how warm the summers usually are, these vegetables might be much more productive than they would have been outside.
Eggplants come from the warm and humid climates of Southeast Asia. Consider “Ichiban” or “Machiaw”—in my experience; these Asian varieties are much more productive than larger-fruited Italian types. And if you have space, include a few hot pepper plants. You’ll be glad you did when those frozen or dried spicy peppers are on hand to use all winter in your cooking projects (of course, sweet peppers freeze nicely too).
Summer squash and zucchini are also heat-lovers and thrive in warm greenhouse conditions. Try the climbing zucchini variety “Trombetta” trained up one of your greenhouse walls. It bears delicious small zucchinis which take on amusing gourd-like shapes when grown to maturity. Mediterranean herbs, such as oregano, marjoram, and thyme will soak up the heat and require less water than vegetable plants.
Although it is relatively uncommon in American gardens, the Asian veggie, the “Yard-Long” bean, loves hot weather. Despite the name, “Yard-Long” beans should really be harvested at length closer to twenty inches. And unlike the standard bush or climbing green beans we usually grow, they produce prolifically in the heat. Their delicious, sweet flavor is most at home in stir-fries; “Yard-Long” beans are vigorous growers–trellis them for maximum productivity and best bean quality.
So don’t leave your greenhouse empty just because it’s getting hot in there. Take advantage of the heat and grow some delicious vegetables!
How To Organize A Greenhouse
Greenhouses are usually positioned with an east-west alignment. The long side faces south, giving the greenhouse the most direct solar exposure in the winter months. During winter, shorter plants should be kept on the south side of the greenhouse and hanging baskets and taller plants on the north side of the house.
A four-plug GFCI outlet should be installed in a convenient location for fans misters and heaters.
With the greenhouse organized into a healthy and productive environment, you’re ready to add plants, start a head start on the growing season, cultivate and raise a variety of beautiful plants.
How to set up a greenhouse
Choosing a suitable greenhouse supplier is only one part of the process. You need to know how to start a greenhouse, and there are important decisions involved in setting up your greenhouse and the equipment you’ll need. The following points show a typical and favorable greenhouse set up.
- Unless you are restricting yourself to growing greenhouse crops such as tomatoes and cucumbers, you will need a bench down at least one side of the greenhouse.
- A shelf above the bench is a useful spot for seedlings.
- If you want to sow from seed and overwinter tender plants in the greenhouse, you will need a power source for a propagator and possibly a heated bench and fan heater.
- If you are going to grow greenhouse crops you will need at least one bed or space for grow bags; grow bags can be stood on a bed to maintain a flexible space
- Ventilation is essential both in the roof (auto vents are simplest) and in the sides; latched windows or louvers allow cross ventilation which helps keep the greenhouse cool in hot weather
- A maximum/minimum thermometer will help you keep an eye on the temperature.
- Internal or external blinds allow flexible shading.
- A paved pathway down the center of the greenhouse provides easy access; watering it in hot weather causes evaporation, which rapidly cools the greenhouse air.
- If you choose a greenhouse with gutters, then you can harvest the rainwater to use in the greenhouse; it also helps to have a tap in the greenhouse or nearby as a backup
- A gravel soakaway around the base of the greenhouse will drain excess water away from the building.
- A paved area around the greenhouse will make it easy to maintain
How to operate a small greenhouse
A mini-greenhouse helps maintain warm temperatures in the soil and air, which aids in seed germination. Most mini-greenhouses have a plastic tray that holds soil or pots and clear plastic covering that allows in light. These greenhouses are usually used indoors, although you can also set them outside during sunny weather if the temperature is above freezing. The clear covering continues to allow light in after the seeds sprout, creating a greenhouse environment during the early plant growth period.
1) Fill the greenhouse planting tray or seedling pots, depending on the greenhouse design, with a sterile potting mix. Fill the water tray with 1 inch of lukewarm water and set the soil tray or pots inside. Allow the soil to absorb the moisture for 30 minutes or until the soil surface becomes moist, then empty the excess water from the drip tray.
2) Sow the plant seeds in the prepared soil mix at the depth specified on the seed packet, usually a depth twice the seed’s width. Plant two seeds per individual pot or planting cell, or sow the seeds 1 inch apart in rows set 1 inch apart in trays and flats. Mist the soil surface with water to moisten it after planting, if necessary.
3) Set the greenhouse cover on top of the tray. Place the greenhouse in a location that receives bright, indirect sunlight where temperatures are between 65 and 75 degrees Fahrenheit. The cover retains moisture in the soil, so it doesn’t need watering until after germination.
4) Prop open the greenhouse cover after the seeds begin to sprout to allow condensation to dissipate. Use a small stick or pencil to hold one end of the cover-up.
5) Water the seedlings when the soil surface dries. Pour water into the drip tray, so the soil soaks up the moisture from the bottom, and the seedling leaves don’t become wet, which can lead to fungal disease. Obliterate the greenhouse cover before the seedlings grow tall enough to touch the plastic.
When can I start using my greenhouse
As any gardener knows, there’s a lot of prep work that must happen before you can begin planting. Before starting seeds, it’s important to disinfect shelves, benches, pots, and trays. While the warm, humid atmosphere of your greenhouse makes it the ideal environment to start seedlings, it’s also the perfect climate for fungi, algae, gnats, and other pests to grow.
Regulating the humidity in your greenhouse with proper ventilation is one way to fight against these disease-causing organisms throughout the year.
As you prepare for another growing season, you’ll also want to keep soil health in mind. If you’re a producer who plants one crop continuously without rotation and are experiencing lower yields than you’d like to see, you may want to consider crop rotation.
When the same crop is planted year after year, the soil can have a buildup of diseases, such as bacterial wilt, bacterial canker, fusarium, and verticillium wilts. These can be remedied by rotating crops and treating the soil with organic or inorganic fertilizers to replenish soil fertility. (For example, you could grow onions or cauliflower this year if you grew tomatoes in the same spot last year.)
How can I make my greenhouse successful
With little effort, you can nail anything. There are some tips which you can keep in mind, and undoubtedly you’ll be successful.
- Automatic vent openers. (Prevents greenhouse from overheating and uses no electricity)
- Pea gravel over landscape fabric for the floor. (Spray water on rocks in summer to help keep greenhouse cooler.)
- Oscillating fans are year-round but especially important in winter to prevent cold spots and disease. (Clip-on variety frees up shelf space.)
- Gutters to fill rain barrels (also will help prevent splashing if flowers/crops are planted alongside greenhouse).
- Shade cloth is essential in summer if the greenhouse is situated in full sun. (Vegetables love full sun, but full southern sun in a greenhouse will cook plants.) Many different weaves for the desired amount of shade.
- Keep a greenhouse journal—fun to track high and low temperatures daily for a monthly summary. Also, write down what seeds were planted, how planted (covered, uncovered, …etc), and how long it took to germinate—Will help in deciding what seeds to grow in the future.
- Propagation mats with thermostat help with successful germination do not have to depend on the heater in winter.
- To prevent pests and disease in the greenhouse, DO NOT overwinter plants that have been outside or are already sickly. (People love to ask if they may overwinter their tender plants in greenhouse…learn to say “no”).
- Water seeds/seedlings from the bottom to prevent damping off.
- Ants love greenhouses…recommend perimeter treatment at the first sign of ants. (Will have giant “ant farm” if they find a way into the chambers of the twin wall.)
- Do not use yellow sticky traps for greenhouse gnats. Prevent gnats by not overwatering. (Traps not only gnats but spiders, ladybugs, and an occasional wren.)
- Use a wireless temperature transmitter to keep track of highs and lows…make sure it has an alarm to alert someone that the temperature has gone below the desired temperature.
- For seed starting, make sure to use sterile germinating medium, clean/disinfected trays, and pots. (1 part bleach to 9 parts water is sufficient.)
- Learn what whiteflies and their eggs look like. Very hard to get rid of if they become established in the greenhouse.
- Common beneficial insects will come to your greenhouse. Learn what their eggs and larva look like so they are not killed. (ladybugs and green lacewings especially)
- Check seeds/seedlings several times/day. Make sure the greenhouse is not too hot or too cold, seedlings not too dry or too wet…sort of like the story Goldilocks and the Three Bears…needs to be “just right” for optimal success.
- When cold, use warm water to water as very cold water will shock the seedlings and slow growth.
- Use diluted fertilizer to feed seedlings. Full strength will “burn” roots.
- Most importantly, have fun and smile with the joy of growing plants.
Now, I hope you’ve all your answers about how to use a greenhouse for beginners.