Soil And Irrigation Commercial potting soil is good for the average home garden greenhouse, especially if you're growing veggies in large beds rather than smaller houseplant pots. These soil mixtures should include sand, peat moss, perlite, vermiculite, and fir bark for adequate drainage. The only time you need to water is when the soil is dry. Over watering in a climate-controlled greenhouse environment has been the death of many a plant or seedling. While many greenhouse owners prefer the control of hand watering, drip irrigation systems are effective and also prevent the leaves from getting too much water on them.
Drip systems are gentle on seedlings, too.
You may not need to water every day. It's wise to study the water requirements of your particular greenhouse and document your regime in a gardening notebook. This makes it easier for a friend or neighbor to take care of your plants when you're busy or out of town. Each type of greenhouse will have its own maintenance requirements. One general rule is to regularly disinfect the entire greenhouse-with a scrub brush and a mixture of diluted bleach, being careful not to get any on your plants.