Safe to Plant

Zinnia · Linxia Chengguanzhen, Gansu, China

When to sow zinnias in Linxia Chengguanzhen

Main outdoor window

19 May - 2 Jun

The window this page is built around.

Timed from last spring frost

12 May

In Linxia Chengguanzhen, on your chosen risk.

Ready to pick

18 Jul - 7 Aug

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 Linxia Chengguanzhen

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

14-28 Apr

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

Sow direct

19 May - 2 Jun

One week after your last frost.

Plant out

19 May - 2 Jun

One week after your last frost.

In flower

18 Jul - 7 Aug

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 Linxia Chengguanzhen

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 Linxia Chengguanzhen.

The median frost-free season here is 148 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 Linxia Chengguanzhen →

Growing zinnias in Linxia Chengguanzhen

When should I plant zinnias in Linxia Chengguanzhen?

Aim for 19 May - 2 Jun in an average year. If you would rather not gamble on the weather, wait until 29 May - 12 Jun - by then frost has finished in nine years out of ten.

When will zinnias be ready to harvest in Linxia Chengguanzhen?

Expect to start picking around 18 Jul - 7 Aug, 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.