Gladiolus · Handan, Hebei, China
When to sow gladioli in Handan
Main outdoor window
6 Apr - 4 May
The window this page is built around.
Timed from last spring frost
23 March
In Handan, on your chosen risk.
Ready to pick
1 Jul - 30 Sep
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 Handan
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
6 Apr - 4 May
After the last frost, once the soil has warmed. This crop is never fully dormant, so it cannot be planted bare-root in winter.
In flower
1 Jul - 30 Sep
Gladioli through the year
Against the frost risk in Handan
Why these dates
Plant corms after the last frost once the soil is above 12C, 10cm deep, and keep planting at two-week intervals until midsummer for a succession of spikes. Tall cultivars need staking or a sheltered spot; a spike in full flower is top-heavy and snaps at the base in wind.
Killed by frost at about -2C. The corms will not survive a freezing soil, so below zone 8 lift them once the leaves yellow, dry them for a fortnight and store frost-free.
Gladioli are planted once and then left in place, so there is no sowing offset to resolve. Nor is there a dormant season to plant into: this crop keeps its leaves and keeps growing through the winter, which is exactly why cold damages it. The window on this page therefore waits until the last frost in Handan has passed and the soil has begun to warm, giving the roots the longest possible run before the cold returns.
Handan sits in zone 7b, which is colder than this crop is rated for, so it will need winter protection or a container that can be moved under cover. The dates below still describe the right time of year; the open question is survival rather than timing.
Also in Handan
Other flowers to time
Growing gladioli in Handan
When should I plant gladioli in Handan?
Aim for 6 Apr - 4 May in an average year. If you would rather not gamble on the weather, wait until 22 Apr - 20 May - by then frost has finished in nine years out of ten.
When will gladioli be ready to harvest in Handan?
Expect to start picking around 1 Jul - 30 Sep, based on 70 to 100 days to maturity from the planting date calculated for this location.
How much frost will gladioli tolerate?
Killed by frost at about -2C. The corms will not survive a freezing soil, so below zone 8 lift them once the leaves yellow, dry them for a fortnight and store frost-free.