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No frost in sight Last frost normally in 26 days (7 May), but frost-free in the forecast.

Growing season

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 11 Apr
Daylight
10+ h
14+ h
10+ h
26 Feb
15 Apr
28 Aug
16 Oct
232 days
Frost-free
10% frost-free
7 May
11 Oct
90% frost risk
157 days
Effective
7 May
11 Oct
157 days

The growing season in Kärret is approximately 157 days and is limited by frost.

Last spring frost

The last spring frost normally occurs on 7 May in Kärret. At the earliest, the last frost is over around 21 Apr and at the latest around 15 May.

Frost-free probabilityFrost-free prob. Date Grower's risk level Explanation
10% 21 Apr High risk Frost 9 out of 10 years after this date
25% 2 May Frost 3 out of 4 years after this date
50% 7 May Normal risk Frost every other year after this date
75% 10 May Frost 1 out of 4 years after this date
90% 15 May Low risk Frost 1 out of 10 years after this date
Growing is often planned around the date when there is a 50% probability that the last spring frost has occurred. In Kärret that is 7 May. If you want lower frost risk, choose 75% or 90%, i.e. a later date.

First autumn frost

The first autumn frost normally occurs on 11 Oct in Kärret. At the earliest, frost can arrive around 28 Sep and at the latest around 1 Nov.

Frost probabilityFrost prob. Date Grower's risk level Explanation
10% 28 Sep Low risk Frost 1 out of 10 years on or before this date
25% 6 Oct Frost 1 out of 4 years on or before this date
50% 11 Oct Normal risk Frost every other year on or before this date
75% 18 Oct Frost 3 out of 4 years on or before this date
90% 1 Nov High risk Frost 9 out of 10 years on or before this date
Growing is often planned around the date when there is a 50% probability that the first autumn frost has occurred. In Kärret that is 11 Oct. If you want lower frost risk, choose 10% or 25%, i.e. an earlier date.

Daylight & Persephone Period

Plants need at least 10 hours of daylight to grow actively. The period with under 10 h is called the Persephone period.

From To Number of days
Daylight over 10 h 26 Feb 16 Oct 232
Persephone period 17 Oct 25 Feb 133
Plan the year's last sowing of cold-hardy plants in Kärret so they are approximately 75% mature by 17 Oct when daylight drops below 10 h and growth starts to slow.

Daylight periods

Long-day plants like lettuce, spinach and coriander bolt when daylight gets too long. Plan sowing and harvest during periods when daylight is shorter (10-14 h). Early spring or late summer sowing gives the best results.

Season Light Period Days Advice
Shorter daylight 10-14 h 26 Feb – 14 Apr 48 Grow long-day plants like spinach, lettuce and coriander.
Longer daylight 14+ h 15 Apr – 27 Aug 135 High risk of bolting
Shorter daylight 10-14 h 28 Aug – 16 Oct 50 Grow long-day plants