Although they live indoors, houseplants “know” what season it is by the length of daylight and the angle of the sun. Winter days can be short and dark, and when the sun does appear, it is low and in the southern portion of the sky. Similar to the plants outside, indoor plants slow their growth and go somewhat “dormant” for winter from October through February or early March.
Frequently, indoor plants struggle during winter months due to various factors:
- Changes in available light
- Cold drafts from windows or frequently used doors
- Hot/dry air from furnace vents, heaters, or fireplaces
- Relocation for holiday reasons (Christmas tree, etc.)
We have compiled a list of winter houseplant “Dos and Don’ts” to help you and your plants thrive this season.
- Water less frequently. Decrease watering to almost half and make sure plants do not sit in wet drainage saucers—water only when plants show signs of being dry with room-temperature water.
- Increase humidity by using a pebble tray or humidifier, or by misting plants twice daily (especially beneficial for ferns and Calathea).
- Rotate plants regularly to encourage balanced growth.
- Inspect plants weekly and dust/clean off leaves with neem oil, gentle shower spray, or water and a soft cloth.
- Avoid cold drafts from windows or frequently used doors
- Keep clear of heater vents, fireplaces, or wood stoves—place diverter on floor vent if possible.
- Re-pot from October through February: Dormant, tropical plants will be slow to adjust to their new environment which could lead to overwatering problems such as fungus gnats or root rot. If soil is compacted and hard, use a pencil or chopstick to gently aerate by making several vertical holes, and try watering from the bottom by setting plant in a basin of water for several minutes until it has absorbed water from the holes in the bottom of the pot.
- Fertilize right now: Most plants photosynthesize so efficiently that they are using up stored energy during winter; added nutrients are unnecessary and may cause a brown or black tip “burn” on foliage as the excess fertilizer is processed. A very diluted, organic liquid or gentle product like Joyful Dirt may be used when necessary. Compost tea or worm tea can be used to help increase the soil microbe population or worm castings can be applied as a thin top dressing, but should be covered lightly with a layer of potting soil to promote water absorption.
- Expect to see much growth on plant cuttings or divisions: Avoid doing much indoor plant propagation during winter. Trimming off dead or yellowing leaves is okay and should be expected, as some plants reallocate nutrients from lower leaves to areas higher up on the plant resulting in color changes and occasional leaf-drop.
7 Basic Rules for Successful Indoor Plants
- Let them rest during the winter (October-February)
- Accept the loss of “temporary” plants
- Give them extra humidity (group them together)
- Treat problems promptly
- Learn to re-pot when needed
- Don’t drown them; water on a schedule with seasonal variation
- Choose wisely!
General Care & Requirements
- Shade: Well away from windows, but enough light to read a newspaper
- Semi-shade: Near a sunless window or some distance from a bright window
- Bright, indirect light: On a sunless windowsill or near a bright window
- Some direct sunlight: On or close to an east-or west-facing windowsill (may need protection from hot summer sun)
- Sunny window: On or close to a south-facing windowsill (may need protection from hot summer sun)
Water: Factors include type of plant, soil condition, light exposure, time of year, size of pot, drainage
Temperature & Humidity: Misting, humidifiers, and pebble trays
Soils & Fertilizer: Most soils are peat-based; we use G&B and Malibu brands; fertilize about every 4-6 weeks (or a less concentrated amount every time you water)
Repotting: Best done when plant is actively growing, rather than during dormant season
Other Tips: Rotate plant for balanced growth, remove spent blooms, dust off foliage
Type of Container: Ideally, your container should have drainage holes. If not, have a plan to remove excess water at the bottom of the pot and to keep the plant out of it, or use the pot-in-pot method with a plastic insert pot!
- Overwatering or other cultural problems
- Establish a watering schedule; adjust it seasonally
- Want a plant in a spot that plants won’t grow well? Buy 2 and rotate them out every 2 weeks!
- Grow lights? YES!
- Common pests include aphids, mealy bugs, scale, thrips, fungus gnats, whitefly, and spider mites. Neem oil and other oil-based sprays have excellent success rates on most common pests; spray target plant when inside a large plastic garbage bag, then seal bag with twist-tie and let stand overnight.
Choosing a Plant
Plants for Low Light:
- Zamioculcas (ZZ plant)
- Aglaonema (Chinese Evergreen)
- Sansevieria (Snake Plant)
- Spathiphyllum (Peace Lily)
Plants for Bright Light:
- Cacti and succulents
- Most flowering plants (kalanchoe)
(tolerant of adapting to various light conditions and temperature/humidity levels)
- ZZ plant
- Cast Iron plant*
- Snake plant
- Heart-leaf philodendron
- Spider plant*
More “Advanced” Plants:
- China Doll
- Most Ficus, especially F. benjamina, F. lyrata (Fiddleleaf Fig)
Great resource: www.houseplant411.com