Growing and using your own herbs can add interest and flavor to your favorite dishes, from spaghetti sauce to fresh salads. Growing herbs is easy because most of them thrive on neglect. However, many herbs are frost tender, making them perfect candidates for residence in a greenhouse. Your greenhouse can be small or large, simple or complex, with automated vents and misting systems. You can economically build a simple greenhouse with two-by-fours and corrugated clear fiberglass that will provide shelter for your frost tender herbs, enabling you and your loved ones to enjoy them year-round.
Plant your herbs in pots that are large enough to allow for the plants' root systems. One-gallon nursery pots are generally a good size. Make sure the pots have drainage holes.
Provide light in your greenhouse. Even if your greenhouse gets natural light, the roof will filter sunlight.
Heat your greenhouse if your winter temperatures regularly drop into the teens, or lower. Many herbs only need shelter from frost in the winter, so unless you are growing summer annuals such as basil in the winter, a cool greenhouse will suffice.
Control insects such as aphids, scale and spider mites with insecticidal soap spray.
Fertilize once each month with a balanced fertilizer.
Provide humidity if your climate is dry. Setting up a drip watering system with sprinklers on a timer can help to keep the area moist, but many herbs prefer to dry out between waterings. Watch your pots for signs of excessive moisture and adjust your misting and watering schedule to allow plants to dry out.
Set up one or more fans to keep the air circulating, depending on the size of your greenhouse. This will help to prevent certain insects and fungal diseases.