How to Increase Humidity for Houseplants:

How to increase humidity for plants starts with knowing your target: most tropical houseplants are happiest around 50–70% RH (relative humidity) with gentle airflow. Below you’ll get quick tests, the truth about trays and misting, the best humidifiers (medium vs. large), and a Bluetooth hygrometer pick so you can stop guessing.

TL;DR

Aim for 50–70% RH near foliage, keep leaves dry, run a humidifier (the king of humidity), and use light airflow. Grouping plants helps a little. Trays and casual misting don’t move the needle in open rooms and can invite issues. For balanced care, remember light increase can raise transpiration needs. Pair higher light with a humidity plan

Why humidity matters (and what low RH looks like)

• Crispy tips/edges (especially on new leaves, thin leaves, or variegates).
  
  
• Tight, slow unfurling on aroids/ferns; leaf margin browning.
  
  
• Spider mites thrive in dry air.
  
  
• Soil dries fast but growth stays “tired.”
  
  

Targets by plant type (guideline, not law)

• Tough tropicals (ZZ, snake, pothos): 40–60% RH
  
  
• Aroids (philodendron, monstera, syngonium): 50–70% RH
  
  
• Ferns, calatheas, anthuriums, hoyas in active growth: 60–75% RH
  
  
• Cuttings/rehab (in domes/prop boxes): 70–85% RH with venting
  
  

High humidity without airflow invites disease. Keep air moving gently past leaves (not at them).

Two quick tests (no gear needed)

1. Leaf-edge check: If newest leaves crisp while watering and light are on point, RH is likely too low.
   
   
2. Bathroom reality check: Park a fussy plant in a post-shower bathroom 2–3 days. If it perks up, humidity is your bottleneck.
   
   

If you want to know exactly how many “% humidity” your plants are getting

This is the best Bluetooth hygrometer at leaf height to see your real numbers (and the daily lows/highs). You can actually track 2-years of export data!

What actually raises humidity (rank-worthy, ordered by impact)

1) Run a humidifier - the reliable fix (and our two picks)

• Large room / whole-home corner: The Hiswelle 4.5-gal (17 L) ultrasonic with wheels and built-in humidistat covers up to ~2,000 ft², pushes up to 800 mL/h, and can run up to ~48 h on low. Great when you want to set 40–90% RH and let it hold.

Why go large vs. medium? Capacity and coverage. The 17 L tank humidifier + higher output means fewer refills and the ability to move an entire living room toward 50–60% RH; the 3 L is quieter and tidier for a desk/bedroom, but you’ll refill more often and it won’t lift a big space on its own.

Placement & care tips: 2–4 ft from plants, blowing past leaves (not at them), empty daily, deep-clean weekly.

Group your plants (you’re probably already doing this)

Leaves transpire; clustering nudges local RH up a few points. It’s helpful, just not magic in a big, breezy room.

Prop boxes / enclosed cabinets (for cuttings & divas)

Closed or semi-closed spaces (terrariums, greenhouse cabinets like a MILSBO) actually hold moisture, with vents/fans to prevent stale air. Great for cuttings or humidity-hungry species.

What doesn’t really help (and why)

Humidity trays (aka pebble trays)

In typical open rooms, trays raise humidity minimally. Air currents disperse the moisture. They can also breed algae/mold and attract fungus gnats if water sits stagnant. We don’t recommend them unless you’re inside a largely closed environment (terrarium/cabinet) where vapor can accumulate. Use a humidifier instead.

Misting

Misting bumps humidity for minutes, then the air reverts. It can also increase disease risk on leaves in still air. If you love misting, do it inside an enclosed cabinet (with fans) or while a humidifier is already running. Otherwise it won’t hold room RH where you need it. 

A quick note from us 🌿

Got questions about your specific room, humidifier size, or a tricky plant? Drop a comment below. We love talking plants and we’re happy to sanity-check your setup.

Seasonality (why winter hurts)

Heating season can drop homes to 20–35% RH. Expect to:

• Add or upsize humidifiers (large unit for living spaces, medium for nooks).
  
  
• Reduce hot, direct afternoon sun stress.
  
  
• Water a touch more often as air gets drier, while keeping the mix airy.
  
  

Acclimating post-shipping (humidity edition)

Plants travel sealed and stressed. Ramp like you would light:

• Days 1–3: Normal room RH (40–50%), bright-indirect light, leaves kept dry.
  
  
• Days 4–7: Introduce humidifier or move nearer your cluster; aim +5–10% RH.
  
  
• Days 8–14: Step to 50–70% RH with gentle airflow.
  Pair with bright-indirect light; from our Rehab guide: after long shipping, acclimate light over 7–14 days
  
  

Troubleshooting at a glance

• Crispy new growth: Raise RH toward 60–70%, keep leaves dry, add a fan on low.
  
  
• Mold/algae/gnats around trays: Ditch trays, clean area, switch to humidifier + airflow.
  
  
• White dust on furniture: That’s from ultrasonic units + hard water. Use distilled water or an evaporative model.
  
  
• Recurring spider mites: RH too low + stale air; bump humidity and rinse foliage weekly.
  
  

FAQ

What humidity do most houseplants like?
Many tropicals do well at 50–70% RH with gentle airflow; tougher plants tolerate 40–60%.

What’s the fastest way to raise humidity?
A humidifier near a grouped plant corner. Large units can lift entire living areas; medium units are perfect for a plant nook/bedroom. Specs above. 

Do pebble trays and misting work?
Trays and casual misting have minimal, short-lived effect in open rooms; trays can invite algae/gnats, and misting can raise disease risk. Use them only inside enclosed cabinets/terrariums—with airflow—or skip them. 

How do I measure humidity?
We like to use a Bluetooth hygrometer at leaf height; log min/max to catch overnight dips.