Eternally Green: A Greener Greenhouse and Gardens
In the last three years the greenhouses and surrounding cut-flower gardens have gone through a transition from conventional techniques towards organic methods. In previous years, the outside gardens were covered with black plastic to keep down the weeds; each planting was fed with non-organic, manufactured chemical fertilizer and irrigated with wasteful, overhead sprinkler systems. Inside the greenhouses we used chemical pesticides and fertilizers.
We moved towards sustainable, organic methods for our health and for stewardship of the planting area. Today in the cut-flower gardens, the plastic cover has been replaced with mulches such as pesticide-free grass clippings provided by our grounds crew and woodchips by our arborist crew. A three-inch depth of these materials suppress weeds and soil borne diseases, decrease water needs, slowly release nutrients, and provide a shelter for beneficial insects (beneficials). Additionally, composted materials from the previous year’s garden are used in the spring as a soil amendment that improves soil health and structure without needing chemical fertilizer.
The garden beds are raised to better utilize space, reduce weeding, and encourage people to stay on the paths. The increased surface area allows for planting crops closer together resulting in a leafier canopy that shades the soil, maintains moisture, and slows weed growth. Water is efficiently applied to the plant roots by using soaker and drip hoses. Plants are also less susceptible to diseases such as mildews, blights, and botrytis.
Companion plants are added to minimize insect and disease problems by increasing beneficial insect diversity. This method attracts a variety of butterflies and bees that pollinate, lady beetles that predate, and wasps that parasitize. Even toads hop over and eat “bad” plant-destructive insects. One toad can eat 100 pests per day. We eliminated pesticides that decrease soil organism populations by interrupting the balance and allowing pest resurgence. Pests re-colonize quickly as they develop resistance to pesticides while the beneficials struggle due to their lower reproductive rates.
In the greenhouses we phased out chemical pesticides and now use organic treatments. Beneficials are released as preventative measures. We switched from a chemical fertilizer to an organic fertilizer made from ground up seeds. The soil media now includes composted material from our recycling yard, reducing our need for outside sources.
Treating our plants and soils with organic methods reflects our own health and well being. Practicing organic floriculture maintains the health of our environment and of ourselves. Stroll through Mount Auburn’s greenhouses and cut-flower gardens. Share in the harmony and connection with the earth. Our use of organic methods in the greenhouses and surrounding gardens sustain employee health, the health of our grounds, and the health of the surrounding ecology.
This article was written by Kelley Sullivan, Greenhouse Horticulturist & Plant Health Care Specialist