Yes, mint can absolutely survive winter indoors. From our perspective as plants, this transition from the outdoor garden to your home is a significant change, but with the right care, we can not only survive but continue to provide you with fresh leaves. Here is a detailed explanation of what we need.
Before the first hard frost arrives, you must bring us indoors. A sudden freeze will damage our leaves and roots, making recovery difficult. Gently dig up a section of the mint plant, ensuring you get a good portion of our root system (rhizomes). Place us in a pot with fresh, well-draining potting mix. Please do not use garden soil, as it can compact in containers and harbor pests. Initially, keep this pot in a shaded area outdoors for a few days to help us acclimate before the final move indoors—this "hardening off" process reduces transplant shock.
Our survival hinges on mimicking our preferred growing conditions as closely as possible indoors. Light is our most crucial energy source. Place us in your sunniest window, ideally a south-facing one where we can receive at least 4-6 hours of direct sunlight daily. Without sufficient light, we will become leggy, with weak, stretched stems and pale leaves as we desperately reach for a light source. If natural light is limited, supplement with a grow light for 12-14 hours a day. We also prefer cooler temperatures, ideally between 65-70°F (18-21°C) during the day and slightly cooler at night. Keep us away from heat vents, radiators, and cold drafts, as extreme temperature fluctuations cause us stress.
Our growth will slow considerably during the winter months. This is a natural period of semi-dormancy for us. Consequently, our water needs decrease. Water us deeply only when the top inch of soil feels dry to the touch. We dislike having our roots constantly wet, as this leads to root rot, which is often fatal. It is better to be slightly underwatered than overwatered. You will notice we require far less fertilizer, if any at all. Feeding us while we are not actively growing can lead to a harmful buildup of salts in the soil and force weak, spindly growth. It is best to wait until spring resumes to fertilize.
The warm, dry indoor air is a magnet for certain pests that rarely bothered us outdoors. Spider mites, aphids, and whiteflies are the most common adversaries. They suck the sap from our leaves, weakening us and causing stippling, yellowing, and wilting. Regularly inspect the undersides of our leaves. A strong spray of water in the sink can dislodge many pests. For more persistent problems, insecticidal soap or neem oil are effective treatments. Good air circulation around our leaves also helps deter these pests.
