Hortuli

Search for your location to see a personalised planting calendar, frost dates and more.

Log in
Svenska
English
Dansk
Smulterskäret
Create your calendar
Create your calendar

Growing Season: Smulterskäret

Norrbotten, Sweden

Growing season

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 9 May
Daylight
10+ h
14+ h
10+ h
5 Mar
8 Apr
5 Sep
8 Oct
217 days
Frost-free
10% frost-free
7 May
20 Oct
90% frost risk
166 days
Effective
7 May
8 Oct
154 days

The growing season in Smulterskäret is approximately 154 days and is limited by both frost and daylight.

Last spring frost

The last spring frost normally occurs on 7 May in Smulterskäret. At the earliest, the last frost is over around 1 May and at the latest around 20 May.

Frost-free probabilityFrost-free prob. Date Grower's risk level Explanation
10% 1 May High risk Frost 9 out of 10 years after this date
25% 6 May Frost 3 out of 4 years after this date
50% 7 May Normal risk Frost every other year after this date
75% 17 May Frost 1 out of 4 years after this date
90% 20 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 Smulterskäret 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 20 Oct in Smulterskäret. At the earliest, frost can arrive around 12 Oct and at the latest around 7 Nov.

Frost probabilityFrost prob. Date Grower's risk level Explanation
10% 12 Oct Low risk Frost 1 out of 10 years on or before this date
25% 17 Oct Frost 1 out of 4 years on or before this date
50% 20 Oct Normal risk Frost every other year on or before this date
75% 1 Nov Frost 3 out of 4 years on or before this date
90% 7 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 Smulterskäret that is 20 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 5 Mar 8 Oct 217
Persephone period 9 Oct 4 Mar 148
Plan the year's last sowing of cold-hardy plants in Smulterskäret so they are approximately 75% mature by 9 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 5 Mar – 7 Apr 34 Grow long-day plants like spinach, lettuce and coriander.
Longer daylight 14+ h 8 Apr – 4 Sep 150 High risk of bolting
Shorter daylight 10-14 h 5 Sep – 8 Oct 34 Grow long-day plants