When does Wall Lettuce bloom in Washington?

Most often in July. Across 140 dated, research-grade observations of Cicerbita muralis in Washington, the flowering season runs roughly July to August.

Peak July In flower 140 Examined 312 State Washington

Flowering 140 in flower of 312 examined

52%

86%

84%

57%

53%

Proportion of examined Cicerbita muralis in Washington in flower, by month
Month	In flower	Examined	Share	95% interval
Jan	0	6	0%	0% to 39%
Feb	0	5	0%	0% to 43%
Mar	1	16	6%	1% to 28%
Apr	1	30	3%	1% to 17%
May	2	49	4%	1% to 14%
Jun	25	48	52%	38% to 66%
Jul	49	57	86%	75% to 93%
Aug	37	44	84%	71% to 92%
Sep	16	28	57%	39% to 73%
Oct	9	17	53%	31% to 74%
Nov	0	8	0%	0% to 32%
Dec	0	4	too few examined

Peak flowering in Jul. Each bar is the share of Cicerbita muralis in Washington 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. 140 of 312 examined observations were in flower, every one of them research grade. The whisker on each bar is a 95% Wilson interval. One month has fewer than 5 examined observations, so no proportion is drawn for it. 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 Washington found Cicerbita muralis in flower, not a forecast. It is computed only from observations made in Washington, 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

Cicerbita muralis

Wall Lettuce

Sourcesevery claim on this page

GBIF (iNaturalist Research-grade Observations). Dated flowering annotations in Washington. 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.