Garden Blog - Top Tropicals

Date: 29 Nov 2020

Cold protection of tropical container plants

Q: I am long time customer of yours, I live in San Diego California and while the summer and Fall temperatures are warm to mild, the winter temperatures dip to a point where some tropicals die off. We are experimenting with different variations of way to heat and insulate the pots we have the tropicals planted in as a way to keep them alive during the colder winter months. I was wondering if you knew of the ideal soil temperature for these tropical in order to look their best year round. All of the heaters we have installed have thermostats and temperature adjustments so we can now keep the soil anywhere between a range of between 65-75 degrees. Any advise you can provide would be greatly appreciated.

A: This is a very interesting concept you are working with. Indeed, keeping pots/roots warm, may help a lot! We've been experimenting with cold protection for a long time - for the above-ground plant parts. For sure keeping roots protected (even with a thick layer of mulch) will benefit tropical plants during winter. In case with container plants, this may help dramatically.
The guideline is, tropical plants slow down or stop their metabolism at 65F. As long as you can keep soil above that temperature - this should work great. Of course, the higher the better.
Optimum temperature for growing tropical plants in general - 70-85F. Above 90F, metabolism stops too, unless it's a heat tolerant, desert plant.

More information on winter cold protection of tropical plants and zone pushing:

Greenhouse in Virginia
Plumeria cold protection
Ghost Cold Protection
Seven rules of cold protection for tropicals
About Cold Protection
Cold protection - winter action for your plant collection
Tropical Treasures articles on zone pushing.

Date: 31 Oct 2025

Black  Bat  Lily  and  White  Bat  Lily  plants  blooming  together  in  the  Top 
 Tropicals  greenhouse,  showing  contrast  between  dark  maroon  and  ivory  bracts 
 with  long  trailing 
 whiskers.

Black and White Bat Lilies (Tacca chantrieri and Tacca nivea) side by side in bloom

How to Care for Bat Lilies

by Top Tropicals Plant Expert Tatiana Anderson

🌞 Light

  • Bright, filtered light. Morning sun or dappled shade is perfect.
  • Avoid direct midday sun outdoors — it can scorch the leaves.
  • Indoors, place near a bright window with sheer curtains or use a grow light.

🌡️ Temperature

  • Warm and stable, ideally 70-85 F during the day.
  • Protect from cold drafts or sudden chills.
  • Ideally, do not let temperature drop below 45 F, although Taccas can tolerate short period of upper 30's.

💧 Watering

  • Keep soil evenly moist but not soggy.
  • Water when the top inch feels barely dry.
  • Use lukewarm water.
  • Avoid letting the pot sit in water.

💨 Humidity

  • High humidity (60-80%) is key.
  • Mist leaves often, use a humidity tray, or keep near a humidifier.
  • In greenhouses or bathrooms with a skylight, it thrives naturally.

🌱 Soil

  • Use rich, loose, well-draining mix
  • Combine bark, peat, and perlite for ideal airflow around the roots.
  • Best mix for growing tropical Tacca in pots - soilless potting mix Abundance . It provides perfect drainage and has a texture similar to a jungle rainforest media.

🍽️ Feeding

  • During growth season (Spring through Fall), feed with Green Magic controlled release fertilizer every 6 months. For even better results, you may apply liquid fertilizer Sunshine Boosters Rubusta.
  • Stop feeding dry fertilizer in cooler months when growth slows. Liquid Sunshine Boosters are safe to use with every watering, year around.

🏡 Indoor Growing

  • Great for bright bathrooms, sunrooms, or any warm, humid corner.
  • Rotate pot occasionally for even growth.
  • Keep away from heating vents and AC drafts.

🌴 Outdoor Growing (in warm climates)

  • Partial shade or filtered light under trees.
  • Excellent in large containers that can be brought inside for winter.
  • Shelter from heavy rain and wind.

Sunshine: "So… it’s a diva?"
Smokey: "Exactly. But take care of it - and it rewards you with wings!"
Smokey and Sunshine: "Happy Halloween!"

🎥 Watch Short Videos:

🛒 Grow your own gothic masterpiece:
Shop Bat Head Lily Tacca

Date: 15 Dec 2025

🌿 Bring the Jungle Inside: Winter Survival Guide. Part 3. Watering and Humidity. ❄️


💦 Water, Humidity, and the Small Things That Decide Who Makes It to Spring

Smokey  the  tuxedo  cat  checks  soil  moisture  and  wipes  a  monstera  leaf 
 while  Sunshine  the  ginger  cat  relaxes  with  a  watering  can  beside  indoor 
 tropical  plants  in  winter.

Smokey:"Still damp. No watering today."
Sunshine:"Great. I am excellent at not watering."
Smokey:"You have been practicing not doing any work your whole life."

In Part 1 (Winter Survival Guide: Temperature) we covered the foundation: light, placement, and acclimation. That is the survival layer.

Part 2 (Winter Survival Guide: Temperature) is about what quietly ruins plants indoors in winter. Not overnight. Slowly.

Most winter losses come from good intentions and habits that worked fine outdoors or in summer, but fail indoors when growth slows.

Watering: Where Most Indoor Plants Die in Winter

If there is one winter skill that matters more than anything else, it is knowing when not to water.

In winter, light is weaker, temperatures are lower, roots stay cold longer, and growth slows or stops. Plants simply do not drink the way they do in summer.

How winter watering actually works

Do not water on a schedule. Winter does not care about your calendar.

Instead:

  • Water thoroughly when you do water.
  • Let excess drain out.
  • Then wait longer than feels comfortable.

Before watering, test the soil with your finger. Water only when the top inch or so is dry.

If the soil below still feels cool and damp, do nothing. That is the hardest skill to learn.

Remember what we covered in Part 1: in winter, soil and roots stay cold much longer. Cold roots absorb water very slowly. Wet, cold soil is not helpful moisture. It is stress.

Waiting is often the correct move.

Common winter watering traps

  • The soil surface looks dry, but the root ball is still wet.
  • Pots near windows dry unevenly.
  • Large pots stay wet for weeks.

Always check below the surface. If the pot feels cold and heavy, roots are not asking for water yet.

Signs you are watering too much

  • Soil stays wet for many days.
  • Pot feels heavy long after watering.
  • Leaves yellow and soften.
  • Fungus gnats appear.

As a rough guideline, most indoor tropicals need 25 to 50 percent less water than summer, sometimes even less in low light.

Always use room temperature water. Cold water shocks roots and slows recovery.

Humidity: Invisible Winter Stress

Winter indoor air is dry. Often far drier than people realize.

Heating systems pull moisture out of the air, and many homes sit at 20 to 30 percent humidity all winter. Most tropical plants prefer something closer to 50 to 60 percent.

Low humidity rarely kills plants outright. It weakens them first. That is why pests show up more often in winter. The plant is already stressed before insects arrive.

What low humidity looks like

  • Brown or crispy leaf edges.
  • Curling leaves.
  • New leaves stuck while unfolding.
  • Spider mites appearing suddenly.

What actually helps

  • Group plants together.
  • Use pebble trays.
  • Run a room humidifier.
  • Use bathrooms if light allows.

Humidity works best when plants are grouped. One isolated plant in dry air struggles far more than a group sharing moisture.

Misting leaves feels helpful, but it only raises humidity for minutes. It does not fix dry air.

Cleaning Leaves: More Important Than It Sounds

Winter light is already weak. Dust makes it worse.

Dusty leaves block light, clog stomata, and create hiding places for pests.

Wiping leaves is one of the simplest winter care steps, and one of the most ignored.

How to clean

  • Soft cloth.
  • Plain water.
  • Mild soap if needed.

Gently wipe. No scrubbing. Every few weeks is enough.

Plants with fuzzy leaves, like African violets, should only be brushed gently with a dry brush.

Clean leaves also make problems easier to see. You will spot mites, scale, or damage early instead of discovering it weeks later.

Winter is not the season to be surprised.

Soil and Pots Behave Differently Indoors

Soil that works outdoors often behaves badly indoors. No wind, lower evaporation, and cooler roots mean the same soil stays wet far longer than expected.

In winter, roots care more about oxygen than water. Soil that stays wet pushes oxygen out, even if the plant looks fine above the soil line.

This is why rot often appears suddenly in late winter, not right after watering mistakes.

Pot size matters

Large pots dry slowly. Slow drying plus cool soil equals rot.

If a plant is barely growing, a very large pot is not doing it any favors.

About repotting

Winter is not the time to repot unless you must.

Only repot if:

  • Roots are rotting.
  • Pests are severe.
  • The plant is clearly failing.

Repotting in winter slows recovery and often makes things worse.

Airflow: Quietly Important

Indoor winter air is still. Still air leads to mold, fungus, and spider mites.

Airflow is not about cooling plants. It is about breaking stagnant air layers that pests and fungus love.

A small fan on low, not blowing directly on plants, makes a big difference. Even gentle movement helps more than people expect.

Drainage and Mold: Boring but Critical

Never let pots sit in water.

Standing water causes root rot, fungus gnats, and mold smell. Always empty trays after watering.

Raise pots slightly so air can move underneath. It helps more than people expect.

If you smell sour soil or a musty odor, something is staying wet too long. That smell is an early warning, not a minor issue.

Fertilizer: Mostly Stop

This is where a lot of winter damage happens.

If a plant is not actively growing, fertilizer does not help. It hurts.

In winter, most indoor tropicals are in maintenance mode, not growth mode. Feeding during this time leads to salt buildup, root burn, and weak, floppy growth.

Green leaves do not mean the plant is growing. They often just mean the plant has not given up yet.

Growth shows up as new leaves, longer stems, or expanding roots. No growth means no feeding.

When light feeding is acceptable

Only if all of these are true:

  • The plant is warm.
  • Light is strong.
  • You see real new growth.

Even then, feed lightly and less often than summer.

Spring will come. You do not need to force it.

Common Winter Care Mistakes

  • Watering on a schedule.
  • Misting instead of humidifying.
  • Fertilizing to fix poor light.
  • Ignoring cold windowsills.
  • Placing pots on cold tile or stone.
  • Repotting out of boredom.
  • Letting trays stay wet.
  • Assuming green leaves mean growth.
  • Assuming winter leaf drop always means death.

Quick Winter FAQ

My soil stays wet forever.
Too little light, too cold, or pot too large. Water less.

Leaves are crispy but soil is wet.
Low humidity combined with overwatering.

Should I mist every day?
No. Fix the air, not the leaves.

Can I fertilize just a little?
Only if the plant is clearly growing.

Why do I suddenly have fungus gnats?
Wet soil indoors is the invitation.

My plant looks fine but has not grown in months. Is that bad?
No. Stability is success in winter.

Date: 30 Dec 2022

Cold protection for tropical plants

greenhouse  and  cold  protection  covers  on  tropical  plants

Pushing the limits of tropical gardening

The year is almost over but the winter is not. This Christmas weekend at our Sebring B-farm we had it down to 30F. As a tropical gardener, winter can be challenging, especially if you grow plants outside of tropical zones.

greenhouse  with  tropical  plants

To protect your garden from the cold, consider the following:

1. Monitor freeze watches and be prepared to take action if necessary.
2. Create temporary structures like mini-greenhouses using PVC pipes, carport frames, or bamboo sticks to support covers.
3. Use covers such as frost cloth, cardboard boxes, blankets, and bed sheets.
4. Use Christmas lights and other heating elements, including propane heaters, to keep plants warm.
5. Add a layer of heavy mulch around plant trunks to protect them from the cold.
6. Apply plant boosters that improve cold hardiness, such as Sunshine Epi, Sunshine-Si, and Sunshine Superfood.

At TopTropicals B-Farm, we sprayed our plants with a special cold hardiness treatment Sunshine-Si and covered and wrapped everything we could. We also moved cold sensitive species inside greenhouses. All of our plants are looking great and happy!

Mulching  mango  trunks  and  using  Christmas  lights  for  cold  protection

Photo above: Mulching mango trunks and using Christmas lights for cold protection

Read more about this special treatment plan: Cold Hardiness Improvement Kit.

Covering  plants  during  cold  night

Plastic  warm  house  wrapping

Photo above: Temporary wrapping of a section of a greenhouse with a plastic or frost cloth protects from a windchill. It may also win you a few degrees even without a heater. In this particular case, according to our temp sensors, it was 30F outside, and 41F inside this "dome", no heaters used.


Sunshine Boosters:

Last chance to stock up
at a lower price!

Sunshine Boosters are natural, amino acid-based liquid fertilizers made with only the highest quality ingredients. Starting in 2023, the pricing for Sunshine Boosters will be adjusting to reflect the increasing cost of supplies. This is your last chance to stock up on Sunshine Boosters before the end of the year! Sunshine Boosters are safe to use year around, with every watering.

Don't miss out on this opportunity to get the best value for your money!

Use discount for even better deal:

22FOR22
for 22% off orders $220+

Min order $220. Offer expires 12-31-22

Sunshine  boosters  for  different  plant  types

Date: 26 Jan 2022

Don't miss this one:
PodCast Premiere!

Episode 1
How to Protect Tropical plants in Winter: Q & A

Featuring Horticulturist Mark Hooten

...We are introducing our new Series: Top Tropicals Podcast. Growing tropicals and pushing the limits. Watch the first episode:

How to Protect Tropical plants in Winter

...Who doesn't like tropical beauty? Everyone wants tropical plants. But not everyone lives in a warm climate. Is it possible to grow tropicals outside of Tropics?
Top Tropicals horticulturist Mark Hooten, who is well known to many gardeners as the Garden Doc with his Saturday Plant Clinic, is answering gardeners' questions about how to prepare and protect tropical plants during winter...

Premiere scheduled:
Thursday, January 27, 8:00 AM

More about cold hardiness and cold protection:

Cold hardy tropical fruit trees
Growing Stephanotis and cold protection
Cold protection of tropical container plants
Plumeria cold protection
Ghost Cold Protection
Seven rules of cold protection for tropicals
Improving cold hardiness before winter: fertilizer and micro-elements
3D garden ideas and winter cold protection
Cold protection - winter action for your plant collection
About Cold Protection