It is nearly impossible to give your plants exactly what they need as often as they need it without some kind of assistance. To optimize growth in the greenhouse environment, the hobbyist may find it beneficial to incorporate the use of accessories to regulate temperature, control humidity, provide water, accelerate growth, and organize plants.

Overall, it is important to remember that selecting the appropriate greenhouse site and structure will significantly reduce energy costs. Factors such as greenhouse size and materials, as well as site location, combine with climatic factors to create your greenhouse’s environment. These factors, combined with the needs of your plants, will ultimately determine which accessories are best suited for your purposes.

The Essential Climate Control Accessory

First and foremost, it will be necessary to incorporate the use of a minimum/maximum thermometer, which will gauge the minimum and maximum temperatures present in your greenhouse in a given period. This crucial tool will help you plan and regulate the use of helpful heating and cooling accessories. Similarly, as temperatures tend to fluctuate, it may be worth looking into automated temperature regulation tools such as thermostats and automated ventilation systems. Accessories such as these will reduce the frequency with which you need to monitor your greenhouse environment.

Cooling and Ventilation

One of the most important features of an ideal growing environment is proper ventilation. Especially during warmer months, your greenhouse can easily become overheated if adequate care is not taken to regulate temperature. Because greenhouses are designed to store heat, it is almost always necessary to have an excellent ventilation system in place to circulate air. Roof and side vents, or louvers, are an easy way to ensure proper exchange of air. To assist in the process of expelling hot air and bringing in cooler air, an exhaust fan ventilation system, using a circulation fan and intake shutters, may be used to accelerate air flow in and out of the greenhouse. During cooler months, when ventilation is still necessary but heat must be maintained, roof and side vents are typically sufficient means of air ventilation. During warmer months, additional steps may need to be taken to ensure that your greenhouse does not become overheated. Some common cooling methods include the following:

• Automated Vent Openers: It may be beneficial to install automated vent openers on your greenhouse vents. With solar-powered vents, heat will build up around the vent's cylinder mechanism on a sunny day, and the vent will slowly start to open. Similarly, as the air cools around the cylinder, the vent will close.
• Misting and Watering Systems: Adequate ventilation, while necessary, may also contribute to decreased humidity in your greenhouse. A humid environment is ideal for plant growth, and reduces the need to constantly water plants. Fogging and misting systems are helpful tools for maintaining humidity because they typically produce very fine water particles that quickly evaporate. This also has a cooling effect.
• Shade Cloths: Especially useful for glass and acrylic greenhouse models, where visibility and light penetration are higher, a shade cloth may be necessary during months of more direct/intense sunlight. Shading is an inexpensive and easy way to protect plants that do not need a great amount of direct sunlight. Also, shading keeps temperatures from rising too high in the greenhouse, reducing energy costs.

Heating

Depending on a variety of factors such as greenhouse construction, plant needs, and climate, your greenhouse may need heating in order to maintain a healthy temperature. If your greenhouse will be experiencing cooler nights and/or winter weather, heat derived from the sun will not be enough. Gas and electric heaters are the most common. The size and strength of your heater should coincide with the amount of space in your greenhouse, the needs of your plants, your climate, and your greenhouse’s ability to insulate. Important factors to remember when heating your greenhouse:

• Safety should always be your primary concern. Consider utilizing safety controls and/or automation tools to regulate your heater’s use.
• Heating can easily become costly. Remember that proper insulation can dramatically reduce heating costs.
• Heaters powered by gas or oil typically produce gases that may be harmful to some plants. Be sure your greenhouse is properly ventilated to prevent plant damage.
• Grow lights may be utilized as an additional heat and light source if your plants require more than what is naturally available.