Pollinator Bloom Calendar
Build a month-by-month bloom timeline for your zone so something is always flowering for the bees.
What this does
Pick your zone and a mix or product. The calendar overlays each species’ bloom window and shows, month by month, what’s in flower — so you can spot gaps and keep forage going from spring to fall.
Overlapping bloom windows
goal: at least one species in flower in every growing-season month
windows shift a few weeks earlier or later by hardiness zone
Every species has a bloom window that moves a little by hardiness zone. The tool overlays the windows for the species in your mix and shades the months when each is flowering.
Sourced bloom windows: white clover roughly May–September, creeping thyme June–August, yarrow June–September — staggered so a good mix carries forage from late spring into fall.
The aim is no gaps: a strong pollinator lawn keeps at least one species blooming in every month of the growing season.
Method & data pinned to: Extension bloom data + Verified Data Layer — v2026-06.
Run the numbers
The interactive Bloom Calendar loads here.
Until then, the formula above gives the same result by hand.
Step by step
- 1. Choose your zone, or enter your ZIP.
- 2. Pick a mix or product.
- 3. Read the month-by-month bloom timeline.
- 4. Look for any months with no bloom.
- 5. Add a species that fills the gap.
Getting an accurate answer
Bloom timing shifts with spring weather, so the calendar shows typical windows rather than exact dates.
First-year stands often bloom later and lighter; the calendar reflects an established planting.
Data source & assumptions
Pinned to Extension bloom data + Verified Data Layer (v2026-06). Assumptions:
- Typical bloom windows by zone.
- Established (not first-year) plantings.
- Mowing temporarily resets clover and thyme bloom.
- Windows are indicative, not exact dates.
Common questions
How do I avoid bloom gaps?
Combine an early bloomer, a midseason one, and a late one. The calendar highlights empty months so you can add a species to cover them.
Will mowing stop the flowers?
Temporarily — clover and thyme rebloom within a couple of weeks. Leaving a section unmowed keeps continuous forage.
Which mix blooms longest?
A clover-plus-thyme-plus-yarrow mix typically carries bloom from May into September across most zones.
Does my zone really change the timing?
Yes — warmer zones start earlier and run longer. The calendar shifts the windows to match the zone you choose.
Keep planning
A single species is an ingredient. The blend is the answer.
Pollinatorlawn Bee Lawn Seed Mix — Prunella + Achillea + 4 fescues + Trifolium repens. A flowering bee lawn; UMN documents 60+ bee species on the clover/self-heal pairing. Buy the blend when the job needs more than one plant — the grass carries the wear, the clover feeds it, the flowers feed the bees. Buy the single species when you want one plant, one look, one job.