Humidity
Too much humidity can allow mold spores and diseases to run rampant in your greenhouse; too little and the plants will die of thirst. Do research ahead of time to group plants together with similar humidity needs. Grow them at the same time, or build more than one smaller greenhouse, if space permits. Misting is an excellent way to increase humidity- find out how much your plants need.
Shade
Even in the winter, your plants may need shade from the sun. The greenhouse cover increases heat inside, so have a system to shade the plants when the sun glares. Mighty Products Heavy Duty Shade Mesh Tarp, 12 x 12-Feet
Ventilation
Without air circulation, the plants will succumb to disease and die. If the greenhouse has no vents, then on sunny days, even in the coldest winter, the heat will rise inside and could cook your plants. Several manufacturers offer automatic greenhouse ventilation systems, both for AC power (hooked up to an outside outlet), or for battery or solar power. This saves you from having to run outside, opening and closing windows all day.
Heating
During the night, the winter temperatures drop dramatically. Even in areas such as south Texas and Florida, greenhouse heaters are needed when temperatures drop below freezing. Do not use a regular house heater for your greenhouse. They are not made for a moist or outdoor environment. Only purchase a heater rated and designed for a greenhouse, and use an outdoor surge protector and outdoor rated power cord.
Plants
Growing the right plants is as important as all the rest put together. Once you’ve looked at your “dream list” of plants, you’ll realize space is the issue for your plants. If you regularly grow vine plants, such as tomatoes, squashes, pumpkins, cucumbers, etc., you’ll want to research and find varieties bred for container growing. Bush varieties of squash require no staking or vines. Plants that are too tall may cause too much shading of other plants. They may come in contact with the greenhouse covering, encouraging disease, mold and mildew growth.
Soil
For a greenhouse, filling containers with common garden soil would be a disaster. Soil compacts, killing the roots. In large containers, the top part of the soil dries out while the bottom of the container becomes bogged with water. The containers become far too heavy to safely lift or move. Use potting soils that have no garden soil in them. A common practice in hydroponic culture is to grow the plants in peat moss or coir (coconut fiber).
Fertilizers
Study the fertilizer and feeding requirements of your plants before you begin. Plants may have different requirements than the standard “feeds-everything” fertilizer. Keep a supply on hand for all your plants. Try grouping your plants according to fertilizer/water/shade needs, or use a marker system to tell you each plant’s requirements. For example, a plant may need more shade like it’s pretty neighbor, but it’s fertilizer requirement may be different. A marker, colored tag or sticker tells you what your plant needs. By studying ahead, your greenhouse growing season will be successful and tasty. Looking for more greenhouse tips and info? You’ll need these guides next:
10 of the Best DIY Greenhouses and Cold Frames For Your Backyard How to Grow Plants Year-Round in an Unheated Greenhouse How to Grow Herbs in a Greenhouse
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