How to Garden Greenhouse Vegetables

Greenhouses extend the growing season.

A greenhouse is an enclosed gardening structure with clear walls that holds enough heat in the winter to support plant development. Greenhouse vegetable growing requires plenty of light and is more economical in regions that have many sunny winter days, as the utility cost of providing artificial lighting is high. The best areas for greenhouses as those that have "high winter light intensity, moderate winter temperatures, low humidity," according to the University of New Mexico.

Things You'll Need

• Greenhouse
• Pen
• Paper
• Seedlings
• Planters of different sizes
• Water
• Fertilizer
• Miscellaneous gardening supplies (gloves, trowel, potting mix, cutters)

Instructions

1. Write down the list of vegetables you would like to grow and divide them into cool-season and warm-season plants. If you're concerned about space, keep in mind that you will be planting these two groups at different times. Shelves will also expand the space inside the greenhouse, if needed.

2. Move warm-season seedlings, including tomatoes, into the greenhouse by mid-August. In the fall, as you harvest these vegetables, move in your cold-season plants, such as spinach, lettuce and onions, for a winter crop. Transplant your seedlings to bigger pots as they develop.

3. Organize your plants around the greenhouse according to how tall they will grow, since the ceiling is a limitation. Lettuce grows close to the ground and can stay on a table or shelf. But some pole bean types can reach 12 feet and will have a better placement on the floor.

4. Maintain your vegetables as you would if they were growing outside. For example, tomatoes thrive in soil that's been amended with nitrogen, and asparagus needs soil with neutral pH. Also, the greenhouse keeps out precipitation. Dip your thumb 1 inch deep into the soil regularly. If the ground feels dry at that depth, water your plants.

5. Pull weeds as they sprout and remove any diseased plant when you notice the problem. Either discard the diseased plant or treat it before returning it to the greenhouse. Infestations spread quickly in an enclosed environment and might wipe out your other crops.

References

• New Mexico State University: Greenhouse Vegetable Production
• Colorado State University Extension: Growing Vegetables in a Hobby Greenhouse
• "Sunset Western Garden Book;" Kathleen Norris Brenzel, ed.; 2001

Resources

• University of Missouri Extension: Managing Whiteflies on Indoor and Outdoor Plants