Plants for a classroom

Classroom Plants: The Holidays Decide, Not the School Year

Every classroom list is scored during term, when the room suits all seven names on it. Shut the building for the summer and shut it for the winter and the same seven sort in opposite orders, with no survivor in common.

Term time: 21 °CShut-up summer: 31 °CSorting question: does the building switch off?

Classroom plant lists are remarkably consistent. Pothos, spider plant, ZZ, snake plant, peace lily, a cast iron plant if the writer is feeling thorough. The lists agree because during term a classroom is an easy room for a plant: a whole wall of glass, heating or cooling holding the air somewhere near 21 °C, and thirty people who notice a wilt.

Then the term ends. The building is locked, the thermostat is set back or switched off entirely, and the room sits at whatever the weather does to it for a week, two weeks, or the better part of three months. That is the part the lists don’t score — and it is where the plants on them actually die.

Ocean Spider Plant

Not the best fit right now

The plant's fine, this spot just isn't a match.

Light

Just the right amount of light

Temperature

Too hot here

Humidity

Humidity suits it

Airflow

Airflow doesn't suit it

Temperature is a deal-breaker here. The other three cannot make up for it.

Worked example: Ocean Spider Plant on a classroom sill in the first week of the summer holidays, the cooling off and the room shut up, air 31 °C and 45% humidity, still airflow. Your spot will score differently. Run it for your own spot →
An empty classroom with a wall of windows, bright light flooding in across rows of unoccupied desks
The wall of glass that makes a classroom easy for a plant during term is the same wall that heats it once the desks are empty.

A classroom is three rooms in one year

Here is what that year looks like to one plant. Hold an east-facing sill at its best light and move nothing but the temperature of the room, and a spider plant — the single most recommended classroom plant there is — is a great fit at 21 and 24 °C, only worth a try at 12, 16 and 27, and not a fit at all at 8, 31 or 35.

That band is almost exactly the band a school keeps its rooms in while people are using them. Step outside it in either direction and the same plant on the same sill goes from a great fit to not a fit at all. Nothing about the light changed. Nothing about the plant changed. The room emptied.

This is the awkward thing about the sorting question for classrooms: it is a question about the building, not about the plant. Two schools with identical rooms, identical windows and identical budgets can need completely different plants, because one of them runs its plant through the summer and the other one doesn’t.

The two ends this page uses are not guesses about a shut building. They are close to what institutions publish as the temperatures a shut building is allowed to reach.

Published byWhat the building is set toWhen
mc.edu55 °F“The unoccupied temperature setting shall be 55°F (i.e. setback).” That is 12.8 °C.
mc.edu60 °F“This may be adjusted to a 60°F setting during extreme weather.”
mc.eduCooling off entirely“During unoccupied times, the air conditioning equipment shall be off.”
roanoke.edu85 °F“Cooling Season Unoccupied Set Points: 85F”. That is 29.4 °C, and it is a ceiling rather than a reading.
roanoke.edu55 °F“Heating Season Unoccupied Set Point: 55F”.
bf.unl.edu55 °F“allow temperatures to drop back to 55°F during unoccupied periods.”
bf.unl.edu85 °F“allow temperatures to rise to 85°F during unoccupied periods.”
hls.harvard.edu60 °F“set room/area thermostats to 60°F” for the heating season in Pound Hall.
hls.harvard.edu80 °F“set room/area thermostats to 80°F” for the cooling season in the same building.
Published unoccupied setpoints from the energy policies of four institutions, copied exactly as each writes them. These are the temperatures a shut building is allowed to reach, not ones we measured. 9 figures transcribed from 4 sources, read end to end on 30 August 2026. Units are copied exactly as each source writes them; nothing here is converted, and nothing here is our own measurement. All of them, from every page, are one free download.

Term time hides the differences

Put the usual seven names on that sill during term and it is easy to see why the lists all agree: only the spider plant is a great fit, and the other six all land in worth-a-try territory, every one of them reading the same comfortable temperature. The counts are in the caption of the next table.

Nothing on the list is a mistake, and note what that does: the spread between those seven is not temperature at all — at 21 °C the room suits all seven — it is the humidity and airflow of an ordinary occupied classroom sitting closer to what some of these plants prefer than others. If your only evidence is the school year, the honest conclusion is that the choice barely matters.

That conclusion survives right up until the last Friday in June.

The holidays are where they split

An empty classroom with two casement windows propped wide open above a radiator, chairs stacked and desks unoccupied
Both of the things that hold the room steady are visible here, and a locked building has neither: nobody opens the window and the radiator is set back.

Same sill, same seven plants, same light. The building is shut and the room has drifted up to 31 °C:

Worth a try Good fit Great fit Golden pothos 62 Spider plant 47 ZZ plant 64 Snake plant 64 Peace lily 57 Cast iron plant 44 Parlor palm 40 Good fit Golden pothos 62 Spider plant 47 ZZ plant 64 Snake plant 64 Peace lily 57 Cast iron plant 44 Parlor palm 40
The plant left on that sillWhat the warmth is doingVerdict
Golden pothosA little warm, but workableWorth a try, 62/100
Spider plantToo hot hereNot the best fit right now, 47/100
ZZ plantA little warm, but workableWorth a try, 64/100
Snake plantA little warm, but workableWorth a try, 64/100
Peace lilyA little warm, but workableWorth a try, 57/100
Cast iron plantToo hot hereNot the best fit right now, 44/100
Parlor palmToo hot hereNot the best fit right now, 40/100
The same seven, left through a shut-up summer. 4 of the 7 come through it and 3 do not. During term on that same sill 1 was a great fit and the other 6 were worth a try, which is why every list agrees. Only one thing moves down the table. The spot itself does not: the same sill through the summer holidays, with the cooling switched off, with 31 °C, 45% humidity and medium airflow held the same on every row. The middle column is only what the warmth is doing. The verdict is the whole spot, so a plant can have the warmth it wants and still lose points on light, humidity or airflow.

And the same sill again over a winter break, with the heating off and the room down at 12 °C:

Worth a try Good fit Great fit Golden pothos 40 Spider plant 65 ZZ plant 42 Snake plant 46 Peace lily 32 Cast iron plant 64 Parlor palm 40 Good fit Golden pothos 40 Spider plant 65 ZZ plant 42 Snake plant 46 Peace lily 32 Cast iron plant 64 Parlor palm 40
The plant left on that sillWhat the warmth is doingVerdict
Golden pothosToo cold hereNot the best fit right now, 40/100
Spider plantA little cool, but workableWorth a try, 65/100
ZZ plantToo cold hereNot the best fit right now, 42/100
Snake plantToo cold hereNot the best fit right now, 46/100
Peace lilyToo cold hereNot the best fit right now, 32/100
Cast iron plantA little cool, but workableWorth a try, 64/100
Parlor palmToo cold hereNot the best fit right now, 40/100
The same seven again, over a winter break with the heating off. Only one thing moves down the table. The spot itself does not: the same sill over a winter break, with the heating switched off, with 12 °C, 45% humidity and medium airflow held the same on every row.

Read those two tables against each other, because the point is in the comparison rather than in either one. The plants that come through the summer are not the plants that come through the winter. The two lists of survivors don’t overlap at all. Worse, the one plant that was a great fit during term is on the losing side of the summer split: the spider plant is cold-hardy enough for the winter break and it is one of the first to go in a shut-up July.

The spider plant is the sharpest example, because it is the name every classroom list leads with. It earns that during term. It is also, in a building that switches the cooling off in July, one of the first plants on the list to go.

What genuinely works

So the recommendation splits, and it splits on a fact about your school rather than about plants:

If summer is the harsh season

  • Golden pothos
  • ZZ plant
  • Snake plant
  • Peace lily: droops visibly when thirsty, which is useful in a room nobody is standing in

If winter is the harsh season

  • Spider plant
  • Cast iron plant

The second column is short, and that is a real finding rather than a gap in the research: cold tolerance and heat tolerance pull in opposite directions, and the pool of houseplants that sit comfortably at 12 °C is genuinely small.

If you don’t know which season is the harsh one in your building, that is the thing to find out before you buy anything. Ask whoever runs the site what happens to the heating and cooling during the long holidays. It is a two-minute question and it decides the whole answer.

What won’t work here (honestly)

Score your own room before the term starts

Every score above comes out of the same engine that runs the free spot checker, applied to a described sill rather than a measured one: we hand it a window direction, a distance, a temperature, a humidity and an airflow, and it returns the verdict. The lux figures are estimates derived from that description, not readings taken in anyone’s classroom. Your own room will differ most in what stands outside the window and in how far the holiday temperature actually drifts — the first of those the arithmetic cannot see, and the second is worth measuring once, over one break, with a cheap thermometer left on the sill.

For the light half of it, the free spot checker estimates your room from the window direction and the distance, in your browser, with nothing to install.

Published August 19, 2026  ·  Last updated August 30, 2026

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Questions, answered honestly

Will a classroom plant survive the summer holidays?

It depends almost entirely on whether the building keeps conditioning the air while it is empty. In a room that drifts to 31 °C, pothos, ZZ, snake plant and peace lily hold on; spider plant, cast iron plant and parlor palm do not.

Is a spider plant a good classroom plant?

During term, one of the best there is. Over a summer holiday in a building that switches the cooling off, it is one of the first to fail — it tolerates cold far better than heat.

Do classroom plants need a grow light?

Usually not: a classroom window wall is generous light by houseplant standards. The catch is that ceiling lights contribute almost nothing, so a plant at the back of the room is living on the window whether it looks like it or not.