How to Keep Your Houseplants Alive and Thriving This Winter
In the winter, our houses get drier, temperatures get colder, and hours of sunlight get shorter.
An extra sweater or two might work for us, but make sure your houseplants are also getting the care they need this winter. Make these seasonal changes to keep your indoor greenery happy during their dormant winter months.
Adjust Your Watering Routine
While the air is much drier in the winter, your plants don’t need more water; in fact, they’ll need somewhat less.
Houseplants don’t grow much during the colder months – they can even go completely dormant – so your typical watering routine might be too generous. Since they aren’t using as much water to grow, giving indoor plants too much water can lead to over-moist soil and root rot. Look out for yellow leaves, which are a sign of overwatering, and avoid decorative pots that don’t provide adequate drainage.
If you water your plants about once a week in the summer, adjust to every 10-14 days in the winter. Keep the specific water needs of each plant in mind and modify their watering schedule proportionately. Some species of cacti, for example, might be able to go a month or longer without water, and others won’t need to be watered at all.
To check if a plant is ready for water, stick a finger into the soil down to the first knuckle to check for moisture and break out the watering can if it’s dry. Given the drier winter air, the soil on top of the pot will dry out faster, so always test the deeper soil to accurately assess moisture levels. Be sure to use room-temperature water as well; very cold water could shock the roots. Let a full watering can sit out overnight, or for at least an hour or so before using.
Because houseplants aren’t actively growing in the winter, delivering nutrients to the soil will only interrupt their natural cycle. Fertilizing dormant plants might do more harm than good, and could cause root burn and salt buildup in the soil. Over-fertilized plants will grow paler leaves and weaker, more spindly stems. Start feeding your plants again in the early spring, or once you start to see new growth.
Temperatures fluctuate much more in the winter, which can be hazardous for plants.
Keep them away from drafty doors and windows, as well as heat sources like fireplaces, radiators, air vents, or even electronic devices. In general, plants prefer temperatures around 75ºF, but temperature fluctuations are just as harmful as extremes, so be sure to keep temperatures constant.
Resist the urge to repot plants during their dormant months. Wait until the beginning of the growing season in the early spring to transfer them to larger containers.
Follow the Light
Days are shorter in the winter, which impacts the amount of sunlight indoor plants receive every day. Monitor how the winter light enters your house and consider repositioning plants so they receive as many hours of sunlight as possible. West- or south-facing windows usually offer the best lighting conditions, if you can make space for a pot or two on the windowsill. Consider what is happening outside the windows as well; trees drop their leaves in the winter, which might make areas that are darker in the summer more favorable in the winter. Windows should also be cleaned frequently to allow the maximum amount of light inside, and if plants start reaching towards the sun, rotate their pots periodically to even out the growth.
If you can’t give plants enough light in the winter (at least six hours), consider using a grow light. Remember that when substituting artificial light for natural light, plants need about double the amount of exposure – so, for a plant that needs six hours of daily sunlight, you’ll want to leave the grow light on for about 12 hours a day. Try, however, to use natural light as much as possible to cut down on unnecessary energy usage.
Keep It Clean
Dust buildup on plants can block their pores and even further decrease the amount of light they receive. With shorter days and less available sunlight, it’s even more important that they capture as much light as possible.
Dusty leaves can also harbor pests and disease, like spider mites that thrive in the dry air.
While plants are dormant in the winter, they can’t grow out of the damage they might incur. Make sure to remove pests and unhealthy leaves from plants, and wipe the dust off of their leaves with a slightly damp cloth, or with a small brush for hairy plants like cacti.
Most plants prefer about 50% humidity, but levels can drop to nearly 10% in homes in the winter.
Using a humidifier near your plants is a good option, but other low-tech solutions can be just as effective, like moving a few pots to areas of the home with high humidity, like the kitchen or bathroom. If you have space, try clustering plants together to create a humid microclimate; when they release water through transpiration, the others can capture that moisture. Otherwise, fabricate your own humidity. Misting plants in the summer can lead to fungal problems, but is a useful strategy during the winter. However, because warm indoor temperatures will evaporate the moisture very quickly, you’ll need to mist the area around your plants several times a day for it to be effective. Alternatively, place a container of water near the plants to evaporate into the air, or fill a tray with water and pebbles that rise above the surface of the water, then place pots on top of the pebbles (but not directly in the water).
Plants are a little less needy in the winter, but they can’t be neglected. If you’re heading out for a winter vacation, make plans for your plants ahead of time. Don’t worry if you’ll only be away from home for a week or less, but otherwise, consider having a plant sitter come by on watering day. Otherwise, thoroughly water plants before departing, then move them away from their light source so they’ll use less water and stay moist for longer.