Tropical Greenhouse Guide

Modern technologies have vastly aided in the development and implementation of improved cultivation. Simultaneously, humans have quickly been decimating our native habitats with modern technology. Before we continue I must urge the reader to exercise caution when altering the native landscape. Many times in human history have we irreparably damaged the landscape around us permanently, and lost species that we can now only reference in literature. 

Tropical Greenhouse Considerations:

In the effort to achieve tropical conditions, one must combat external conditions to produce a relative equilibrium that favors your specific plant stock. The first step in this process is to evaluate your site: evaluate your site for the climate and microclimates that can be created by prevailing wind direction, slope aspect, and other factors. 

Selecting a site that works naturally in your favor will greatly reduce energy consumption necessary for optimal growth. The material and thickness of the greenhouse walls will influence the insulation potential of the greenhouse. In addition to the greenhouse walls, the floor will affect the internal temperature. There are many tools online to help approximate these values.

In the summertime generally heat and light are abundant. Sometimes too much of either or both can negatively affect growth, especially in a confined area space that magnifies heat. Greenhouses generally work this way to combat cold temperatures in winter by amplifying heat and reducing heat lost. 

Summertime Considerations:

In the summer, we are under the assumption that heat and light are abundant. We must combat these forces in order to achieve success when cultivating some tropical plants. Tropical plants generally occur close to the equator, and as a result are highly adapted due to the convenience of relatively consistent day-length. Geographical or geological factors are usually what determines vegetation in these areas. Of course there are more factors such as lineage, rainfall, ect.

Mountainous areas can create intense speciation due to physical and and ecological isolation. For the purpose of this guide; we will discuss how to lower internal summertime temperatures. There are many genera of plants that have adapted to lowland environments with yearly consistent and oppressively high temperatures. These plants do not necessarily need any reduction in temperature and in fact seem to thrive in the highest possible temperature you can provide. 

As elevation gains, average temperature consistently drops due to reduced air density. The air loses heat quickly in the same way that an un-insulated greenhouse would lose heat. Plants have adapted to this environment and we will discuss how to modify greenhouse conditions to achieve cultivation. 

Ways to Cool Your Greenhouse in Summer:

Cold water should be considered the primary means for cooling any greenhouse when ignoring structural factors such as greenhouse build, solar infiltration, ect. When building any greenhouse you need to know if cold water is available. Since water is a poor conductor of heat, it can be used to physically cool a greenhouse structure through various applications. In the most basic sense, a large body of cold water will slow the internal temperature gain of a greenhouse.

The cold water can be used as a thermal mass to partly counteract the heat gained by the greenhouse structure. Flowing cold water is even better, as it continuously maintains the lowest possible temperature due to increased current. It is important to note, only pure water should be used with cultivation. Using non-purified water in a greenhouse setting can certainly lead to nutrient imbalance and growth issues. 

Irrigation is essential to cooling greenhouses. In addition to the methods above water can also work to cool a greenhouse via misting. Mist reduces the incoming solar energy into the system while simultaneously decreasing temperature. As the fine water particles absorb heat they transition from liquid to vapor, keeping the humidity stable and temperature low. Evaporative coolers in greenhouses utilize this cooling process and they work extremely efficiently in dry exterior climates. 

Working in conjunction with misting is air movement. Fans in a greenhouse can do an amazing job to circulate air facilitating the hot air to vent upward. As the fans increase the air circulation, this also increases the evaporative cooling power from water. Air circulation can be somewhat tricky, as too much airflow can damage leaves on fragile plants.

Shade cloth can work well to lower greenhouse temperatures. There are several types of shade cloths available to growers. Many modern cultivators are choosing to go with higher shade cloth percentages in favor of using current LED lighting to achieve desired light levels without wasted energy or unwanted solar intrusion. Black plastic shade cloth will actually absorb a lot of heat so if you are using this color shade cloth for cooling purposes it may actually be working against your desired cooling goals. 

Wintertime Considerations:

In the winter we must work against cold and darkness to grow tropical plants. In northern climates it may seem like an impossible feat to keep greenhouse temperatures above freezing. This guide will present several options available to cultivators to help them keep temperatures high. 

Wintertime can be especially dangerous for tropical plant cultivators as an entire plant stock can be lost with a single freeze. For this reason growers should think outside the box, and utilize a combination of off-grid techniques for achieving and maintaining warm temperatures. 

Ways to Heat Your Greenhouse in Winter:

Greenhouses are best heated in winter by solar energy. As the sun hits the greenhouse it will generate internal conditions that are warmer than the exterior. In climates where solar energy is limited in winter, it becomes proportionally much more important to store that solar energy when it arrives. Installing a shade cloth with less shade percentage in winter can allow more light to enter the greenhouse. 

Storing water in the greenhouse can be a viable way to reduce heat lost in wintertime. Since water is a poor conductor of heat, it slowly loses heat to the environment around it on cold days. Much like how black plastic shade cloth will absorb more light and heat energy, if water is stored in containers made of black material it will also absorb more heat. Heat absorbed during the day is then slowly released at night, which moderates temperatures and reduces the ability of exterior cold from influencing internal greenhouse conditions. 

In addition to water storage, greenhouse materials and build can greatly influence the insulation ability and temperature of the greenhouse. Concrete, rock, or stone floors will absorb solar heat during the daytime. There are advanced geothermal greenhouse systems that can be installed such as ground heat-air transfer systems but here we are mostly discussing non-intrusive options for heating. If you are interested in learning more about ways to achieve tropical greenhouse conditions with building materials we offer consultations here: consultations. 

When utilizing electricity for cultivation it is important to note that your system should be foolproof beyond what the power company can provide you. For this reason it is also recommended to explore solar battery systems which have been used here effectively for energy. 

Heat from electricity can be used in the greenhouse in just about any way. Electricity is also what powers most greenhouse propane and gas heating systems. You can use electricity to bank heat in water with products such as pool heaters. Heat produced directly from electrical heaters can work well heating a space efficiently without the worry of combustion byproducts. Heat lost from greenhouses will usually be greatest at nighttime, therefore heat should be banked during the day in anticipation of night heat loss.