Lemon balm · Osorno, Los Lagos Region, Chile
When to plant lemon balm in Osorno
Main outdoor window
28 Aug - 18 Sep
The window this page is built around.
Timed from last spring frost
11 September
In Osorno, on your chosen risk.
Ready to pick
29 Oct - 30 Apr
If you plant at the start of the window.
The average last frost. Half of all years are later than this.
Step by step in Osorno
Each window is a range, not a single day. Earlier in the range buys you a longer season; later in it buys you a safer one.
Start indoors
17 Jul - 7 Aug
Eight weeks before your last frost, under cover or on a windowsill.
Sow direct
28 Aug - 18 Sep
Two weeks before your last frost.
Plant out
25 Sep - 16 Oct
Two weeks after your last frost.
Harvest
29 Oct - 30 Apr
Lemon balm through the year
Against the frost risk in Osorno
Why these dates
Extremely hardy, to about -25C. Dies to the ground and returns reliably.
Seed packets and extension guides express timing as weeks either side of the last spring frost, because that is the only reference point that travels. Lemon balm are timed from 8 weeks before that frost for an indoor start, with planting out 2 weeks after it, and this page simply resolves those offsets against the frost date computed for Osorno.
Osorno sits in zone 9b, which is milder than this crop wants, and a winter that never really arrives is its own problem. The dates below still describe the right time of year; the open question is survival rather than timing.
Do not expect a crop in the first year. A plant set out now should give its first worthwhile pick around year 1, and will then produce every year after that, which is what makes the planting decision worth getting right the first time.
Growing lemon balm in Osorno
When should I plant lemon balm in Osorno?
Aim for 28 Aug - 18 Sep in an average year. If you would rather not gamble on the weather, wait until 23 Sep - 14 Oct - by then frost has finished in nine years out of ten.
When will lemon balm be ready to harvest in Osorno?
Expect to start picking around 29 Oct - 30 Apr, based on 70 to 90 days to maturity from the planting date calculated for this location.
How much frost will lemon balm tolerate?
Extremely hardy, to about -25C. Dies to the ground and returns reliably.