Siberian squill · Zhenjiang, Jiangsu, China
When to sow siberian squills in Zhenjiang
Main outdoor window
14-28 Oct
The window this page is built around.
Timed from last spring frost
19 March
In Zhenjiang, on your chosen risk.
Ready to pick
1 Mar - 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 Zhenjiang
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 bulbs
14-28 Oct
Four to six weeks before your first frost, so roots form before the ground cools.
In flower
1 Mar - 30 Apr
Siberian squills through the year
Against the frost risk in Zhenjiang
Why these dates
Plant in early autumn, 7cm deep, in generous drifts - a handful of squills is invisible. Self-seeds freely once settled, so put them where spread is an advantage rather than a problem.
Hardy to about -35C, further north than almost any other spring bulb. Requires a genuinely cold winter and does not persist below zone 8.
Siberian squills 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 Zhenjiang instead of forwards from its start.
Zhenjiang sits in zone 8b, 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.
The median frost-free season here is 252 days, against 120 to 160 days to first flower for this crop counted from sowing. That margin is what decides whether a late sowing is worth attempting.
Also in Zhenjiang
Other flowers to time
Growing siberian squills in Zhenjiang
When should I plant siberian squills in Zhenjiang?
Aim for 14-28 Oct in an average year. If you would rather not gamble on the weather, wait until 28 Sep - 12 Oct - by then frost has finished in nine years out of ten.
When will siberian squills be ready to harvest in Zhenjiang?
Expect to start picking around 1 Mar - 30 Apr, based on 120 to 160 days to maturity from the planting date calculated for this location.
How much frost will siberian squills tolerate?
Hardy to about -35C, further north than almost any other spring bulb. Requires a genuinely cold winter and does not persist below zone 8.