Crocus · Frankfurt am Main, Hesse, Germany
When to sow crocuses in Frankfurt am Main
Main outdoor window
26 Sep - 10 Oct
The window this page is built around.
Timed from last spring frost
17 April
In Frankfurt am Main, on your chosen risk.
Ready to pick
1 Feb - 31 Mar
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 Frankfurt am Main
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.
Plant the corms
26 Sep - 10 Oct
Four to six weeks before your first frost, so roots form before the ground cools.
In flower
1 Feb - 31 Mar
Crocuses through the year
Against the frost risk in Frankfurt am Main
Why these dates
Plant in early autumn, six to eight weeks before the first frost, 8cm deep. Naturalising in grass is the best use of them: they flower and set seed before the first cut of the season is due, so the lawn can be left uncut until the leaves yellow in late spring.
Hardy to -30C and among the most frost-indifferent flowers grown - blooms freeze solid overnight and reopen the same morning. Needs a cold winter to flower well and fails in zone 9 and warmer.
Crocuses are anchored to the first autumn frost rather than the last spring one, so the planting window on this page counts backwards from the end of the season in Frankfurt am Main instead of forwards from its start.
Hardiness is not the obstacle here. Frankfurt am Main is zone 8a, comfortably inside the range this crop is rated for, so an established plant should come through an average winter without protection.
The median frost-free season here is 204 days, against 120 to 170 days to first flower for this crop counted from sowing. That margin is what decides whether a late sowing is worth attempting.
Also in Frankfurt am Main
Other flowers to time
Growing crocuses in Frankfurt am Main
When should I plant crocuses in Frankfurt am Main?
Aim for 26 Sep - 10 Oct in an average year. If you would rather not gamble on the weather, wait until 5-19 Sep - by then frost has finished in nine years out of ten.
When will crocuses be ready to harvest in Frankfurt am Main?
Expect to start picking around 1 Feb - 31 Mar, based on 120 to 170 days to maturity from the planting date calculated for this location.
How much frost will crocuses tolerate?
Hardy to -30C and among the most frost-indifferent flowers grown - blooms freeze solid overnight and reopen the same morning. Needs a cold winter to flower well and fails in zone 9 and warmer.