Safe to Plant

Tulip · Najafgarh, Delhi, India

When to sow tulips in Najafgarh

Main outdoor window

not outdoors here

The window this page is built around.

Timed from last spring frost

7 January

In Najafgarh, on your chosen risk.

First autumn frost

no autumn frost

The far end of the outdoor season.

The average last frost. Half of all years are later than this.

Step by step in Najafgarh

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.

Frost tolerance
Very-hardy
Damaged below
-25°C (-13°F)
Days to flowering
150–200
Hardy to
Zone 3a–8a
Spacing
12 cm
Sowing depth
150 mm (5.9 in)
Sun
Full

Tulips through the year

Against the frost risk in Najafgarh

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

Frost risk Today

Why these dates

Plant four to six weeks before your first autumn frost, once the soil has cooled below about 15C - warm soil encourages the rot that hollows bulbs out over winter. Late planting is far less damaging than early; bulbs put in at the start of winter simply flower a little later. Depth matters more than date: 15cm, about three times the height of the bulb.

The bulb is hardy to around -25C once underground. Cold is the requirement rather than the risk: without twelve to fourteen weeks below 9C the stem stays short and the flower opens at ground level or not at all. In zone 9 and warmer, buy pre-chilled bulbs and treat them as annuals.

Tulips 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 Najafgarh instead of forwards from its start.

Najafgarh sits in zone 10b, which is milder than this crop wants, and a winter that never really arrives is its own problem. The dates below still describe the right time of year; the open question is survival rather than timing.

See every crop timed for Najafgarh →

Growing tulips in Najafgarh

How much frost will tulips tolerate?

The bulb is hardy to around -25C once underground. Cold is the requirement rather than the risk: without twelve to fourteen weeks below 9C the stem stays short and the flower opens at ground level or not at all. In zone 9 and warmer, buy pre-chilled bulbs and treat them as annuals.