Date: 6 Dec 2025
🌿 Bring the Jungle Inside: Winter Survival Guide Part 2.Temperature. ❄️
Smokey: Too cold. We need more heaters so the plants feel comfortable.
Sunshine: I feel comfortable.
Smokey: You are not part of my plant collection, but I am glad you are comfortable.
🌡️ TEMPERATURE: THE TROPICAL DORMANCY LINE
In Part 1 (Winter Survival Guide: Temperature) we covered the foundation: light, placement, and acclimation. That is the survival layer.
Most tropicals stop growing below 70 to 75 F. They stay green, but their engine shuts down.
Below 70F:
- Water intake drops.
- Roots slow down.
- Fertilizing becomes risky.
- Root root becomes easy.
If you WANT your plants to grow in winter, you must take care of everything: Warmth, light, humidity, water. It all works together.
- Aim for 75 F with bright light. Water lightly. No fertilizer.
- Watch out for drafts. Cold windows. Door blasts. Garage entryways. Even one gust can trigger leaf drop.
- Vents are the opposite problem: hot, dry, dusty air. That gives you crispy edges and mites. Root zone temperature matters just as much as room air. Your thermostat may say 72 F, but your pot on a tile floor may be sitting at 55 F. Fix this by elevating pots on boards or stands. Use Styrofoam. Never keep pots directly on cold tile o windowsill
- Extra winter heat: Space heaters are fine if used smartly. Do not blow hot air directly on plants. Keep heaters away from cords, trays, and water. Oil filled radiators are the safest option for plant rooms.
- Use a humidifier if you want growth or want to prevent spider mites. But do not blow mist directly onto leaves. Always place the unit lower than the plant canopy.
- Grouping helps. Put tropical plants close together to share humidity. Do not mix succulents with humidity lovers.
- Cats and dogs love to knock over lights and stands. Secure your fixtures. Trust us.
- Airflow: Light airflow is healthy. Direct fan blast is not. Still, dry corners invite mites.
- A mild night drop is OK. A big one below 55 F will stop growth completely.
A mandevilla thriving indoors with bright pink blooms and glossy green leaves.
☂️ PLACEMENT: MICROCLIMATES RULE EVERYTHING
Indoors is one big tradeoff: light but cold near windows, warm but dim away from them. The winning combo is a warm room with supplemental light.
Best zones to keep plants in winter:
- South or east windows with additional light
- Warm living spaces
- Bright bathrooms for natural humidity
Worst zones to keep plants in winter:
- Behind curtains
- Directly on windowsills
- Near heaters or vents
- Against cold exterior walls
- Dark corners without supplemental lighting
A vigorous indoor philodendron stretching across the window.
💨 ACCLIMATION
Moving a plant from outdoors to indoors is a shock. Light drops. Humidity drops. Airflow stops. Soil cools. Even healthy plants may drop some leaves for a few weeks. That is normal.
Before you bring them inside:
- Rinse foliage to remove dust and pests. We recommend Sunshine NoBug - and organic, safe solution.
- Check for ants.
- Trim weak branches.
- Treat soil if fungus gnats are present.
Try to bring plants inside before the first cold front, not after. If you are reading this too late, do the prep now and expect a little leaf drop.
If you nail light and temperature, winter becomes simple. In the next mail-list we will cover watering, fertilizer timing, humidity, and other indoor tricks that keep tropicals happy till spring. Stay tuned.
Cat Bob is inspecting his indoor garden around the tub with a bright skylight
✔️ WINTER INDOOR FAQ: TEMPERATURE AND PLACEMENT
Q: Why are leaves dropping only on the window side?
A: Cold glass. The room may be warm, but the glass surface can be much colder.
Q: Is a cold room OK for tropicals?
A: They may survive, but they will not grow below about 65F to 75F. When nights stay below 65F for a week, many plants enter dormancy.
Q: My room feels warm. Why is my plant still not growing?
A: Check the soil temperature. Pots on cold tile can be 10 to 20F colder than the air.
Q: Can plants sit directly on the floor?
A: Not on cold tile. Always elevate them on boards, stands, or trays.
Q: Is it OK to keep plants near a heater or vent?
A: No. Vents and heaters blast hot, dry air and cause crispy leaves and mites.
Q: My plant is dropping leaves after coming indoors. Why?
A: Normal acclimation to reduced light and humidity right after the move.
Q: Can I keep plants in a bright bathroom?
A: Yes. Bathrooms can have good humidity. Just keep pots off cold tile.
Q: Do I need a humidifier?
A: Not for survival. Yes if you want better growth and fewer pests like spider mites.
Q: Do I need a grow tent?
A: No. A bright LED plus a warm room is enough for winter holding.
Q: Should I fertilize in winter?
A: Not now. Winter fertilizer rules will be covered in the next mail-list.
Q: Should I water the same as in summer?
A: No. Indoor plants need much less water in winter. Watering rules also coming soon.
📚 Learn more:
- Bring the Jungle Inside: Winter Survival Guide Part 1: Lighting
- SUNSHINE NoBug - Natural Plant Protector
- How to overwinter tropical plants indoors
- Feeding indoor plants
- Overwintering Adeniums outside of tropics
