Safe to Plant

Zinnia · Xiantao, Hubei, China

When to sow zinnias in Xiantao

Main outdoor window

6-20 Mar

The window this page is built around.

Timed from last spring frost

27 February

In Xiantao, on your chosen risk.

Ready to pick

5-25 May

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 Xiantao

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.

Start indoors

30 Jan - 13 Feb

Four weeks before your last frost, under cover or on a windowsill.

Sow direct

6-20 Mar

One week after your last frost.

Plant out

6-20 Mar

One week after your last frost.

In flower

5-25 May

Sow in succession. A single sowing gives you a single glut. Sow a short row every 21 days through the window above and you get a steady supply instead.
Frost tolerance
Tender
Damaged below
0°C (32°F)
Days to flowering
60–80
Min soil temp
21°C (69.8°F)
Spacing
25 cm
Sowing depth
6 mm (0.2 in)
Sun
Full

Zinnias through the year

Against the frost risk in Xiantao

Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Frost risk Start indoors Sow direct Plant out Harvest Today

Why these dates

Direct sowing after last frost usually beats transplanting - zinnias dislike root disturbance and catch up quickly.

Killed by the first frost at either end of the season. Strictly a warm-season flower.

Seed packets and extension guides express timing as weeks either side of the last spring frost, because that is the only reference point that travels. Zinnias are timed from 4 weeks before that frost for an indoor start, with planting out 1 weeks after it, and this page simply resolves those offsets against the frost date computed for Xiantao.

The median frost-free season here is 277 days, against 60 to 80 days to first flower for this crop counted from sowing. That margin is what decides whether a late sowing is worth attempting.

See every crop timed for Xiantao →

Growing zinnias in Xiantao

When should I plant zinnias in Xiantao?

Aim for 6-20 Mar in an average year. If you would rather not gamble on the weather, wait until 21 Mar - 4 Apr - by then frost has finished in nine years out of ten.

When will zinnias be ready to harvest in Xiantao?

Expect to start picking around 5-25 May, based on 60 to 80 days to maturity from the planting date calculated for this location.

How much frost will zinnias tolerate?

Killed by the first frost at either end of the season. Strictly a warm-season flower.