Daffodil · Karaj, Alborz Province, Iran
When to sow daffodils in Karaj
Main outdoor window
15-29 Sep
The window this page is built around.
Timed from last spring frost
1 May
In Karaj, 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 Karaj
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
15-29 Sep
Four to six weeks before your first frost, so roots form before the ground cools.
In flower
1 Mar - 30 Apr
Daffodils through the year
Against the frost risk in Karaj
Why these dates
Plant early - four to eight weeks before the first frost, and earlier than tulips. Daffodils make roots in autumn warmth and want that head start. Plant at twice the bulb's height, and leave the foliage to yellow completely after flowering, because next year's flower is built during those six weeks.
Hardy to about -30C, and undamaged by frost on the emerged leaves; the flower buds tolerate a hard frost that flattens everything else. Needs around ten weeks below 9C, slightly less than a tulip, so daffodils persist a zone warmer than tulips do.
Daffodils 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 Karaj instead of forwards from its start.
Hardiness is not the obstacle here. Karaj is zone 6b, 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 179 days, against 140 to 190 days to first flower for this crop counted from sowing. That margin is what decides whether a late sowing is worth attempting.
Also in Karaj
Other flowers to time
Growing daffodils in Karaj
When should I plant daffodils in Karaj?
Aim for 15-29 Sep in an average year. If you would rather not gamble on the weather, wait until 28 Aug - 11 Sep - by then frost has finished in nine years out of ten.
When will daffodils be ready to harvest in Karaj?
Expect to start picking around 1 Mar - 30 Apr, based on 140 to 190 days to maturity from the planting date calculated for this location.
How much frost will daffodils tolerate?
Hardy to about -30C, and undamaged by frost on the emerged leaves; the flower buds tolerate a hard frost that flattens everything else. Needs around ten weeks below 9C, slightly less than a tulip, so daffodils persist a zone warmer than tulips do.