Viola · Tongchuanshi, Shaanxi, China
When to sow violas in Tongchuanshi
Main outdoor window
26 Feb - 2 Apr
The window this page is built around.
Timed from last spring frost
26 March
In Tongchuanshi, on your chosen risk.
Ready to pick
22 May - 16 Jun
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 Tongchuanshi
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
1 Jan - 5 Feb
Twelve weeks before your last frost, under cover or on a windowsill.
Plant out
26 Feb - 2 Apr
Four weeks before your last frost.
In flower
22 May - 16 Jun
Violas through the year
Against the frost risk in Tongchuanshi
Why these dates
Start indoors twelve weeks before the last frost and plant out four weeks before it, or sow in midsummer for autumn planting and winter flowers. Shear back by half in midsummer if it looks exhausted and it will recover for autumn.
Hardy to about -18C, more so than the pansy, and flowers through mild winters. Handles summer heat slightly better too, though it still pauses in the hottest weeks.
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. Violas are timed from 12 weeks before that frost for an indoor start, with planting out 4 weeks before it, and this page simply resolves those offsets against the frost date computed for Tongchuanshi.
Hardiness is not the obstacle here. Tongchuanshi is zone 7b, 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 226 days, against 85 to 110 days to first flower for this crop counted from planting out. That margin is what decides whether a late sowing is worth attempting.
Also in Tongchuanshi
Other flowers to time
Growing violas in Tongchuanshi
When should I plant violas in Tongchuanshi?
Aim for 26 Feb - 2 Apr in an average year. If you would rather not gamble on the weather, wait until 16 Mar - 20 Apr - by then frost has finished in nine years out of ten.
When will violas be ready to harvest in Tongchuanshi?
Expect to start picking around 22 May - 16 Jun, based on 85 to 110 days to maturity from the planting date calculated for this location.
How much frost will violas tolerate?
Hardy to about -18C, more so than the pansy, and flowers through mild winters. Handles summer heat slightly better too, though it still pauses in the hottest weeks.