A good friend of mine told me my gardenias (that are currently inside : ugly looking sticks with a few green-golden leaves) could possibly survive outside in sheltered zone 7 areas.
I have a high esteem for my friend and know she's quite knowledgable about frost hardiness, but i am a bit sceptical about gardenias.
Could someone confirm that?
Regard, Erik.

Erik,
Here are a few cultivars, with estimated temp limit. (these temps are not personal observations but theoretical temps picked on the net)

- "Oregon Gardenia" rated zone 6-9
- "Kleim’s Hardy"
- "Chuck Hayes"

Both Kleim's and Chuck are said to be hardy to 0°F... With heavy damage I assume. Worth trying in zone 7, however!
Kurt

Hello everybody, just wondering.
What is it you call zone? I'm more confortable with celcius temperatures actually. I you have any conversion hint I'd be grateful. Etto

Hello Etto and welcome here
zones here refer to USDA zones :
(quote) :
" The USDA Plant Hardiness Zones divide the United States and southern Canada into 11 areas based on a 10 degree Farenheit difference in the average annual minimum temperature "

In other words :

Zone 1 : Below -50°F (-45.6°C)

Zone 2 : -50 to -40°F (-45.6 to -40°C)

Zone 3 : -40 to -30°F (-40 to -34.5°C)

Zone 4 : -30 to -20°F (-34.5 to -28.9°C)

Zone 5 : -20 to -10°F (-28.9 to -23.3°C)

Zone 6 : -10 to 0°F (-23.3 to -17.8°C)

Zone 7 : 0 to 10°F (-17.8 to -12.3°C)

Zone 8 : 10 to 20°F (-12.3 to -6.6°C)

Zone 9 : 20 to 30°F (-6.6 to -1.1°C)

Zone 10 : 30 to 40°F (-1.1 to 4.4°C)

Zone 11 : > 40°F (> 4.4°Cà

So it is fairly easy. To know in which USDA zone you live, just compare the absolute minimum temperature of one average year with the table.

Example : if you live in a place where winter temps reach down to -8°C (that's what I understood from your posts. You live in USDA zone 8 (and more precisely zone 8b, as zones are subdivided in two 5°F wide subzones)

Hope it helps
Kacey

Hello Kacey,

Many thanks for this kind and complete answer, I'll save this message for future reference!
I thus believe my garden is in USDA 8b to 9a, useful to know that! Etto.