When does red maple bloom in Maryland?

Most often in February. Across 58 dated, research-grade observations of Acer rubrum in Maryland, the flowering season runs roughly February to March.

Peak February In flower 58 Examined 401 State Maryland

Flowering 58 in flower of 401 examined

93%

80%

Proportion of examined Acer rubrum in Maryland in flower, by month
Month	In flower	Examined	Share	95% interval
Jan	0	2	too few examined
Feb	13	14	93%	69% to 99%
Mar	44	55	80%	68% to 88%
Apr	1	108	1%	0% to 5%
May	0	43	0%	0% to 8%
Jun	0	38	0%	0% to 9%
Jul	0	26	0%	0% to 13%
Aug	0	30	0%	0% to 11%
Sep	0	20	0%	0% to 16%
Oct	0	44	0%	0% to 8%
Nov	0	19	0%	0% to 17%
Dec	0	2	too few examined

Peak flowering in Feb. Each bar is the share of Acer rubrum in Maryland 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. 58 of 401 examined observations were in flower, every one of them research grade. The whisker on each bar is a 95% Wilson interval. 2 months have fewer than 5 examined observations, so no proportion is drawn for them. 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 Maryland found Acer rubrum in flower, not a forecast. It is computed only from observations made in Maryland, 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

Acer rubrum

red maple

Sourcesevery claim on this page

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