The Greenhouse Environment as Mini-Ecosystem

Here's a comprehensive explanation of the mini-ecosystem that makes up the greenhouse environment and how to manage it for maximum effectiveness.

| November/December 1984

greenhouse environment, mini ecosystem - pink flowers

Even to flowers in a pot, the greenhouse environment is a mini-ecosystem.


In the early 1970s, when energy costs first began their upward spiral, accelerating fuel prices drove many commercial glasshouse vegetable producers right out of business. This inflationary upswing also started a modest new trend in American gardening.

With the price tag on winter tomatoes and other warm-weather crops on the rise, many people equipped their homes with attached greenhouses, which ranged from expensive, custom-built models to low-budget, low-tech structures composed of plastic-covered frames.

We've now become accustomed to seeing such food- and flower-producing add-ons everywhere. There's no longer any reason to limit a passion for vegetables and flowers to the outdoors. Even those gardeners new to greenhouse management can be successful at indoor horticulture by following four basic rules.

Know Your Greenhouse Environment

Each attached greenhouse has its own environment, which is created by its location, design, construction, glazing, thermal mass and interior layout.

A solar greenhouse, more than any other type, is sensitive to its surrounding environment. In many ways, this type of greenhouse is analogous to a living plant cell: The sun is its primary energy source, and its glazing acts as a membrane between the inner and outer world, allowing an exchange of heat, light and air. A greenhouse can, in fact, become a mini-ecosystem if the adept gardener can manage the interaction between abiotic factors (such as wind, snow, oxygen, carbon dioxide) and the biological community.

At New Alchemy Institute, we call our greenhouses "bioshelters," because our biotic residents include more than just green plants. The bioshelter grower manages soil that's alive with tiny microorganisms and other animals that break down organic matter into humus. Plant-feeding, plant-pollinating and plant-predaceous insects stake out their own niches. Most of the flora is edible, but a small percentage of space is reserved for herbs, flowers and woody plants. Even the heat storage acts as a substrate for living organisms, since we use transparent water columns laden with green algae and stocked with phytoplankton-feeding fish, or bank huge masses of compost against the north wall. Any grower can become proficient at this type of biological management when treating the greenhouse as an ecosystem. The key is to let nature be your guide.

mother earth news fair


Oct. 21-22, 2017
Topeka, KS.

More than 150 workshops, great deals from more than 200 exhibitors, off-stage demos, inspirational keynotes, and great food!