Growing Conditions Explained


Understand Our Climate Codes

Every plant we sell has a climate code on its pot stake. It’s our shorthand for the temperatures a plant wants, based on where it grows in the wild and, more importantly, how it does in our own greenhouses.

Why temperature, not altitude?

In the tropics, it gets cooler as you climb a mountain, so elevation is a handy guide. But it’s only a guide. Small, isolated mountains run cooler than big mountain ranges at the same height (botanists call this the Massenerhebung effect). So we think in temperatures, and we trust what our plants tell us over what a map says.

The codes

CodeNameTypical homeDaysNights
LLLowlandWarm tropical forest, roughly 500 to 1,000 m80 to 90 F (27 to 32 C)65 to 70 F (18 to 21 C)
INIntermediateLower mountain slopes, roughly 1,000 to 1,500 m75 to 85 F (24 to 29 C)55 to 65 F (13 to 18 C)
HLHighlandCloud forest, roughly 1,500 to 2,000 m70 to 80 F (21 to 27 C)50 to 60 F (10 to 16 C)
UHLUltra HighlandMossy summits above 2,000 m65 to 75 F (18 to 24 C)45 to 55 F (7 to 13 C)
TMTemperatePlaces with real wintersWarm summersA cold winter rest

The night drop is the secret

Most highland plants can handle a warm afternoon. What they can’t handle is a warm night, every night. If you can give them cool nights, you’re most of the way there. Our own highland house drops to about 52 F at night, which is why some “ultra highland” plants are perfectly happy in it.

Temperate plants need winter

TM plants, like the cobra lily (Darlingtonia) and the European butterworts, rest through a cold winter. Skipping that rest is the most common way to lose them slowly. Darlingtonia also needs cool roots all summer.

Hybrids sit in between

A hybrid’s code comes from weighing both parents. A cross between a highland and a lowland plant usually grows best as an intermediate.

Your conditions matter more than ours

These codes are a starting point, not a rulebook. Many plants are more adaptable than their code suggests. If you’re not sure whether a plant will suit your setup, ask us. We’d much rather help you pick the right plant than sell you the wrong one.

Happy Growing!