Some Greenhouse Tips

The most important thing you must do when you build a greenhouse is to brace the structure securely before winter sets in, especially if you live in an area that gets snow. When the snow load accumulates on a big structure, all your hard work can be destroyed rather quickly. Suggested support is to add 2-by-4 vertical braces to the framing as soon as possible to avoid any kind of disaster.

The next important tip is to provide adequate ventilation. If you plan to use your greenhouse for growing vegetable crops during the summer, you will need heavy-duty exhaust fans and roll-up sides. However, if your greenhouse is for the purpose of growing during the winter, all you need to do is just leave the doors open once in awhile to provide adequate ventilation. Any exhaust fan is superfluous.

Caring for the soil used in your greenhouse is as important as the air. Using compost is a good idea in that this will help boost the microbial populations in the soil. Mulches have benefits, too. They will moderate the temperature in the soil, conserve moisture and decompose over time to increase fertility. There are advantages to leaving the greenhouse soil fallow over the summer. Soil “solarizes” in intense heat burning off soil pathogens. Also, this practice will desiccate even the most die-hard slug!

Avoid over fertilizing with nitrogen. Especially in the low light conditions of a winter greenhouse, green leafy crops can accumulate unhealthy levels of nitrates. Never add nitrogen fertilizers in the greenhouse. Always use plant-based rather than manure-based (higher in nitrogen) composts.

Since the greenhouse is usually too hot for direct sowing in late summer and early fall, when most winter crops need to be started, a common practice is to start growing the plants for your greenhouse as seeds under grow lights in your house, perhaps in the basement. When they get too big for the grow bench, move them into the greenhouse.

Some greenhouse crops to consider are salad-oriented. Lettuces are quite resistant to frost, though not as cold hardy as some other winter garden plants. Chicories are an excellent choice to grow during the winter. If you’ve been turned off by the stringy, bitter taste of endives and escaroles you buy from the supermarket, be assured that the chicories grown in the chill and reduced light of a winter greenhouse taste sweet, and the stringy toughness is replaced by a delightful juicy crunch. Other cold hardy crops are the edible chrysanthemum and miner’s lettuce or claytonia. Scallions are also easy to grow in a greenhouse and a delightful addition to winter salads.

Green onion and garlic tops also make great cooking greens. Spinach is extremely cold hardy and several sowings can be made during the winter growing season. Crucifers including mustards, Oriental greens such as pak choi and tatsoi, and chard are all are tasty and nutritious. If you start your transplants early enough, loose leafed kale is an excellent crop for the fall-winter greenhouse. Brassicas that head such as cabbages and broccoli produce later in the winter large, tight heads grown in the greenhouse.

Dayelle Swensson is an avid writer for the web on a number of topics. Having gardened herself for many years, she is able to advise others about a variety of things including gardening tips, lawn and tree care, watering, hose reel and keeping your home garden looking good and healthy.