UK temperature
Keeping florist's gloxinia warm in a UK home
Sinningia speciosa
More about florist's gloxinia in the UK
The UK home, in plant terms
A typical UK home creates two opposite micro-problems at the same time. Radiator-driven heating spikes the air temperature and crashes humidity in the rooms where people actually sit; the older the housing stock the more likely a single-glazed window pane is sitting at near-freezing in January with a houseplant against it. Cold unheated bedrooms, north-facing rooms and conservatories without heating run far cooler than the thermostat suggests, and the British winter gives the lowest indoor daylight in any of Growli's markets. Florist's Gloxinia is frost-tender, so the radiator-warmed side of the house is right for it in winter — just not pressed against a cold pane or directly in the radiator updraft.
The actual numbers
Ideally florist's gloxinia sits between 18-24C. (That is 65-75F in Fahrenheit.) Native to humid Brazilian forests, it wants consistently high humidity. Stand the pot on a tray of damp pebbles or run a humidifier nearby; do not mist the leaves directly, as water on the velvety foliage causes spotting and rot. Dry indoor air leads to crisping leaf edges and bud drop. Watch for the room dropping below about 18°C overnight — common in UK unheated bedrooms in January, and the point where growth stalls and leaves chill-mark.
For the RHS hardiness side of this, see is florist's gloxinia hardy in the UK? (rating RHS , sourced from the RHS rating system). For the US/USDA framing of the same numbers, see the florist's gloxinia temperature guide.
Winter placement in a UK home
For florist's gloxinia through a UK winter, three placement rules clear up most problems: 1) keep it at least a hand's width back from the window pane on single-glazed or very cold double-glazed glass, especially overnight when curtains close behind the plant; 2) keep it out of the direct vertical updraft above a radiator — that column of hot dry air browns leaf tips even on tolerant species; 3) judge by the room you can actually feel, not the central thermostat — many UK rooms run several degrees below the hall reading in winter. Humidity drops to roughly 25–35% in a heated UK living room; a pebble tray, grouping with other plants, or a small humidifier puts that back to a level houseplants actually like.
Florist's Gloxinia temperature in the UK — frequently asked questions
What temperature does florist's gloxinia need in the UK?
Florist's Gloxinia prefers 18-24C (65-75F). The British issue is rarely the average — it is the extremes: a cold single-glazed window in January, the hot dry air directly above a radiator, or a north-facing unheated room that runs far cooler than the hall thermostat.
Will florist's gloxinia survive a cold UK winter room?
Florist's Gloxinia is frost-tender (RHS undefined). Keep it well above freezing, ideally above 10°C overnight, which means the radiator-warmed side of the house rather than an unheated bedroom or conservatory.
Can florist's gloxinia go on a UK windowsill in winter?
On a single-glazed or very cold pane, no — overnight the leaves pressed against the glass can drop below the plant's comfort band, especially behind drawn curtains. A small gap (a hand's width back) or thicker thermal curtains in front of the plant fixes it, and modern double-glazing usually solves it outright.
Does UK radiator-driven heating dry florist's gloxinia out?
Yes — UK living rooms typically run at around 25–35% relative humidity in winter. That is well below what most houseplants prefer. Florist's Gloxinia tolerates this better than the calathea-and-fern family, but a pebble tray or grouping plants still helps.
What temperature range does florist's gloxinia actually like?
18-24C is the comfortable band (65-75F in Fahrenheit for reference). That covers normal UK living-room temperatures all year; the work is making sure cold pockets (windowsills, unheated rooms) and hot pockets (radiator updrafts) do not push it outside that band.
More florist's gloxinia care
See the full florist's gloxinia care guide, its UK watering (hard vs soft tap water), and UK hardiness.