When does sticky whiteleaf manzanita bloom in California?

Most often in March. Across 559 dated, research-grade observations of Arctostaphylos viscida in California, the flowering season runs roughly February to April.

Peak March In flower 559 Examined 1,097 State California

Flowering 559 in flower of 1,097 examined

58%

76%

87%

79%

41%

15%

10%

26%

Proportion of examined Arctostaphylos viscida in California in flower, by month
Month	In flower	Examined	Share	95% interval
Jan	48	83	58%	47% to 68%
Feb	107	140	76%	69% to 83%
Mar	178	204	87%	82% to 91%
Apr	143	182	79%	72% to 84%
May	65	158	41%	34% to 49%
Jun	9	59	15%	8% to 27%
Jul	0	81	0%	0% to 5%
Aug	0	51	0%	0% to 7%
Sep	0	51	0%	0% to 7%
Oct	0	40	0%	0% to 9%
Nov	2	21	10%	3% to 29%
Dec	7	27	26%	13% to 45%

Peak flowering in Mar. Each bar is the share of Arctostaphylos viscida 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. 559 of 1,097 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 Arctostaphylos viscida 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

Arctostaphylos viscida

sticky whiteleaf manzanita

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.