After the gleam of the holidays ends, the dawning realization begins to set in – you’ve still got a lot of winter to go!

For most of the country, the few months between autumn and spring can be some of the coldest and gloomiest times of year. While that can already have an effect on people, there’s something else in your home that can be affected by the cold and dark outside – your plants!

Plants being grown and harvested in an indoor grow room are just as susceptible to temperature changes outside as anything else in your home, and no matter how ‘indoors’ your grow room may be, special care needs to be taken to prevent damage to your plants. Most grow rooms aren’t prepared right out of the gate to deal with the drastic changes in temperature and humidity that wintertime brings with it, and even the most elaborate indoor grow operation will need a little help to get it truly ready for wintertime.

Here’s five of our favorite ways to get your grow room ready for the winter months, and how you can keep your plants safe in the process:

Clean your plants and the room itself

It might sound sort of silly or counter-intuitive, but a lot of houseplants and indoor crops can find themselves covered in dust and other house-crud over the warmer months. Debris like dirt, dust, and mold can start to cause greater health problems for your plants when it comes time to use the heater in your home. Depending on your plants, you may be able to clean them with a mixture of mild dishwashing soap and water to remove dirt and potential mold, and then you’ll want to do a good sweep and scrub of the room to remove dust, excess dirt, and spilled water.

Keep the door closed

A lot of grow room owners think they can use cold air from outdoors as a replacement for air conditioning, especially during a time of year where the utility bills tend to be pretty high as it is, but the cold air can actually be much more damaging on your plants as it can introduce contaminants. Use indoor air conditioning and/or industrial fans to help move air in your grow room, and keep the door closed to prevent ambient temperature from affecting the quality of air inside.

Allow for airflow

Similarly, most grow rooms will need to keep a close eye on their airflow capacity to make sure certain plants aren’t being kept too dry or too prone to mold growth due to their proximity to the air sources in your grow room. Make sure to spread your grow room shelves out far enough to not block or unintentionally direct the air in your grow room, and arrange your plants in a way that they’re all receiving an equal amount of air flow.

Insulate the walls

Depending on where in the house you’ve set up your grow room, you may need to provide additional insulation to maintain temperatures. Areas like bedrooms or hallway closets tend to be well-insulated and away from colder areas of the house, but if your grow room hasn’t been properly insulated or is surrounded by outside-facing walls, you may need to take steps to boost up the insulation. If standard residential wall insulation is an option you may want to add some to your walls and ceiling, or if not you can acquire reflective wall paneling that can better trap the proper temperature inside the room. Make sure things like hydro tables and drying racks are far enough away from the wall to prevent ambient temperature from affecting your plants.

Boost your lighting

A frequently-overlooked source of temperature regulation in grow rooms is the sort of lighting you use. If your industrial LED lighting can accept higher-powered bulbs, switch from 400- or 600-watt bulbs to 1000-watt bulbs to double your BTU output and provide ambient warmth for your space. This can serve double-duty in grow rooms that use ducts to extract heat – by using your lights as a primary heat source, you can reduce the need for the heat extractor and keep your plants comfier than ever during the winter months.