Growing Season: Bjurfors
Vindeln, Västerbotten, Sweden
-2.4°
Slight frost
tomorrow morning at 06:00. Frost temperatures between 21:00 – tomorrow 07:00.
Bring in or cover sensitive plants
Growing season
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
11 Apr
Daylight
10+ h
14+ h
10+ h
4 Mar
9 Apr
3 Sep
9 Oct
219 days
Frost-free
10% frost-free
3 Jun
2 Sep
90% frost risk
91 days
Effective
3 Jun
2 Sep
91 days
The growing season in Bjurfors is approximately 91 days and is limited by frost.
Last spring frost
The last spring frost normally occurs on 3 Jun in Bjurfors. At the earliest, the last frost is over around 22 May and at the latest around 18 Jun.
| Frost-free probabilityFrost-free prob. | Date | Grower's risk level | Explanation |
|---|---|---|---|
| 10% | 22 May | High risk | Frost 9 out of 10 years after this date |
| 25% | 27 May | Frost 3 out of 4 years after this date | |
| 50% | 3 Jun | Normal risk | Frost every other year after this date |
| 75% | 10 Jun | Frost 1 out of 4 years after this date | |
| 90% | 18 Jun | 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 Bjurfors that is 3 Jun. 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 2 Sep in Bjurfors. At the earliest, frost can arrive around 16 Aug and at the latest around 18 Sep.
| Frost probabilityFrost prob. | Date | Grower's risk level | Explanation |
|---|---|---|---|
| 10% | 16 Aug | Low risk | Frost 1 out of 10 years on or before this date |
| 25% | 21 Aug | Frost 1 out of 4 years on or before this date | |
| 50% | 2 Sep | Normal risk | Frost every other year on or before this date |
| 75% | 11 Sep | Frost 3 out of 4 years on or before this date | |
| 90% | 18 Sep | 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 Bjurfors that is 2 Sep. 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 | 4 Mar | 9 Oct | 219 |
| Persephone period | 10 Oct | 3 Mar | 146 |
Plan the year's last sowing of cold-hardy plants in Bjurfors so they are approximately 75% mature by 10 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 | 4 Mar – 8 Apr | 36 | Grow long-day plants like spinach, lettuce and coriander. |
| Longer daylight | 14+ h | 9 Apr – 2 Sep | 147 | High risk of bolting |
| Shorter daylight | 10-14 h | 3 Sep – 9 Oct | 37 | Grow long-day plants |