By Jennifer Ruisch
When the weather outside is frightful... Heat it up in your grow room!
In the wintertime, the interiors of most homes experience environmental fluctuations. When you turn on your furnace, the temperature increases and the air dries out like a desert. The cold wind outside finds ways to creep in under doors and through rickety windows. Depending on where you keep your indoor garden, you may have several metaphorical mountains to climb. There are lots of ways to battle the changing climate inside your house, and fight the good fight for your plants. First, you need to identify your enemy.
Make a climate map of your house. You know where the heat registers are. You know there's a draft that comes in under the front door. Knowing these things will surely help you know where to situate your plants, but take it a step further. Get a few thermometers and put them around your place. Get creative. Put one on the floor, one on the counter, and one close to the ceiling--do this all over your house. Keep track of the different temperatures around your place, and you might be surprised where the cold spots are, and where the breezes coming from your doors and windows carry. Once you know where the cold and hot spots are, you will know what areas you need to warm up or cool down.
First, let's talk about warming up the cold parts. This is the most common battle, as your plants can't tolerate cold, and it's a common fight to have on your hands. It starts at the ground and moves up from there.
Pull your plants up, ya bum! The cold ground loses heat because it rises up. The cooler, more dense air falls to the floor and sticks around, right where you want to set your pots and reservoirs. This is especially true with concrete floors. One of the simplest things to do is to elevate your plants. This can be achieved in different ways. Raising your water reservoirs and containers up off the floor will allow a cushion of air to form beneath them, regulating the temperature. In the case of cement floors and marble, tile or granite counter tops, you have what's called a “cold sink”. These materials pull heat away from objects and drain it away. You can also get yourself a heat mat! Heat mats are some of my favorite items to use to increase your growing success. They are cost effective in that they are relatively inexpensive, and they won't rack up your electric bill the way a space heater will. Space heaters also dry out the air, requiring a humidifier. A heat mat will gently raise the temperature around the root area of your plants, without drying out the air above, which will suck the moisture out of the leaves, buds and fruit of your plants. It's as easy as putting your pots on a pallet, and slipping a heat mat under them. Get a heat mat thermostat to keep the temperature precise. You can program the heat mat to shut off at a predetermined temperature.
Turn down the heat. What do you do with the opposite problem? When the cold air blows outside, and you crank the heat to keep warm, you may create a harsher environment for your crop. Blasting the furnace saps all the moisture from the air, so your job is to replenish it, or pay the price. You will need to apply more water to your container gardens, and you’ll need to top off the water in your hydro reservoirs due to loss from evaporation. Outdoors, water vapor in the air acts as a blanket, stabilizing temperatures. This is why it gets so cold in the dry desert at night. As soon as the sun goes down, all the warmth goes off into the atmosphere for lack of something to hold on to. If you keep the humidity stable in your home, the conditions will be more predictable and less harsh. Your plants won't have to fight so hard to keep hold of their own internal moisture. Fans move air around, and can help regulate temperature by creating a flow around your plants. Fans also help to cool down lights, which can get even hotter than usual when the furnace is working double time. Make sure your ballasts are cooled properly, and don't keep your humidifier in close proximity to your electrical equipment, or stored substrate, in case of a spill.
If you do some climate detective work, you can identify your exact problem, and then you can work toward remediating the issue, or issues at hand.