When does desert willow bloom in California?

Most often in June. Across 591 dated, research-grade observations of Chilopsis linearis in California, the flowering season runs roughly May to September.

Peak June In flower 591 Examined 1,059 State California

Flowering 591 in flower of 1,059 examined

10%

57%

87%

97%

82%

87%

68%

43%

10%

Proportion of examined Chilopsis linearis in California in flower, by month
Month	In flower	Examined	Share	95% interval
Jan	1	74	1%	0% to 7%
Feb	0	51	0%	0% to 7%
Mar	9	91	10%	5% to 18%
Apr	116	204	57%	50% to 63%
May	143	165	87%	81% to 91%
Jun	74	76	97%	91% to 99%
Jul	33	34	97%	85% to 99%
Aug	36	44	82%	68% to 90%
Sep	73	84	87%	78% to 93%
Oct	70	103	68%	58% to 76%
Nov	30	70	43%	32% to 55%
Dec	6	63	10%	4% to 19%

Peak flowering in Jun. Each bar is the share of Chilopsis linearis in California observations in which someone actually recorded the reproductive state and found the plant in flower, not the raw number of flowering records. That distinction matters: people observe plants far more in spring than in winter, so a bare count of flowering records partly measures when people go outside. Dividing by the number examined removes that. 591 of 1,059 examined observations were in flower, every one of them research grade. The whisker on each bar is a 95% Wilson interval. This is still a global aggregate and not a forecast for your garden: the same species flowers on different dates in different hemispheres. Where a species has fewer than 30 flowering records we do not draw this chart at all. Computed from 10.15468/dl.wt38fd.

What this is, and what it is not

This is a record of when people in California found Chilopsis linearis in flower, not a forecast. It is computed only from observations made in California, so it is not the species’ global average dragged onto a map: the same plant flowers on different dates in different places, and that is the entire point of the page.

It will not tell you what your particular plant will do this year. Bloom time moves with the season, with altitude, and with the weather, and a warm February pulls everything forward. We publish the distribution and the sample size, and we refuse to draw a month that too few people examined.

The plant

Chilopsis linearis

desert willow

Sourcesevery claim on this page

GBIF (iNaturalist Research-grade Observations). Dated flowering annotations in California. Every record achieved iNaturalist quality grade Research, which is applied upstream at export. 10.15468/dl.wt38fd. Retrieved 2026-07-14.
World Flora Online Plant List. The accepted name. CC0. Retrieved 2026-07-12.