How to Grow Plants in a Greenhouse

Gardening in a greenhouse can add months to the beginning and end of your growing season. Even beginners can be successful at greenhouse gardening. Whether gardening through the winter, or starting plants earlier in the spring, even a small greenhouse can be fruitful: a 3 by 10-foot plot can yield up to 100 heads of lettuce, or a 2 by 3-foot plot a dozen carnation plants. Your greenhouse can quickly become a worthwhile investment, yielding many opportunities, otherwise dormant, throughout the winter.

Things You'll Need

• Heating system
• Ventilation system
• Flats or seed boxes
• Soil
• Water
• Pots

Instructions

1. Choose a greenhouse right for the space, money and time you have available. You can either purchase a greenhouse kit or design and build one yourself. Greenhouses are not only made with sturdy frames and glass paneling, but often can be made with a PVC pipe frame that is glazed with a thin clear plastic called 6-mil. Small lean-to greenhouses, adjacent to the home, are also a good option.

2. Control the environment of your greenhouse. Heat your greenhouse with a passive or active system. Passive systems such as water storage tanks or rock beds use energy from the sun to heat the greenhouse at night, while active systems require another source of energy--electrical, gas, wood stove--to heat the greenhouse. Choose the right heating system for your specific greenhouse.

3. Circulate air throughout the greenhouse. Windows or ventilation intakes and exhausts should make up no more than 25 percent of the total glass surface. Develop a system of vents and fans to circulate air, preventing diseases and mold. Louvered windows work well in climates where winter temperatures do not fall too low. Place the flats somewhere warm, and water only if the soil appears to be drying out.

4. Sow seeds in your flats or seed boxes. Fill your flat or seed box with a good-quality potting soil, and place your seeds inside. Poke holes in the bottoms to allow proper drainage. Soak your flat or seed box in 1 inch of water, until you can see moisture at the top of the soil. Place the flats somewhere warm, for one to two weeks, and water only if the soil appears to be drying out.

5. Transplant your seedlings to deeper flats, or small pots. Water your flat of seedlings the day before you transplant them. Fill your new flat or pots with soil, and poke holes to allow for drainage if necessary. Lift a bunch of seedlings out with a flat stick or transplanting fork. Select strong and healthy seedlings, and pick them out of the soil with your thumb and forefinger. Make a small hole in the new flat with your finger, and place the seedling in it. Secure the seedling with soil. Repeat this process until your new flat is full of strong seedlings. Soak the flat immediately after completion, and place in a warm sunny place. Water only when the soil appears to be drying out.

6. Transplant your small plant into a larger pot. Remove the seedling from its flat or small pot. Networks of roots surround the soil, forming a root ball. Fill your new larger pot with soil. Make a hole in the center deep enough for the root ball to be covered by 1/2 inch of soil. Place the root ball in the new pot. Cover the root ball with soil and secure the plant. Repeat this process as the plant grows and needs a larger pot to flourish. Water and fertilize as necessary for each specific plant.

References

• Book: "Gardening Indoors and Under Glass"; F.F. Rockwell; 1912
• Book: "How to Build Your Own Greenhouse"; Roger Marshall; 2006