What's flowering for honey bees near Portland, OR (Willamette Valley), month by month — 37 local nectar and pollen sources.
Open the interactive, printable calendar →← More Oregon bee forage calendars
| Plant | Scientific name | Category | Bloom months | Forage value |
|---|---|---|---|---|
| Filbert/Hazelnut | Corylus avellana | Trees | Jan–Feb | medium |
| Red Alder | Alnus rubra | Trees | Feb–Mar | medium |
| Willow (various) | Salix spp. | Trees | Feb–Apr | high |
| Domestic Plum/Cherry | Prunus domestica / Prunus avium | Trees | Mar–Apr | medium |
| Oregon Ash | Fraxinus latifolia | Trees | Mar–Apr | low |
| Oregon Grape | Mahonia aquifolium | Shrubs & Vines | Mar–Apr | medium |
| Salmonberry | Rubus spectabilis | Shrubs & Vines | Mar–May | medium |
| Red-flowering Currant | Ribes sanguineum | Shrubs & Vines | Mar–Apr | medium |
| Dandelion | Taraxacum officinale | Wildflowers & Weeds | Mar–May | high |
| Bigleaf Maple | Acer macrophyllum | Trees | Apr–May | high |
| Apple | Malus domestica | Trees | Apr–May | medium |
| Douglas Fir | Pseudotsuga menziesii | Trees | Apr–May | low |
| Vine Maple | Acer circinatum | Shrubs & Vines | Apr–May | medium |
| Black Locust | Robinia pseudoacacia | Trees | May–Jun | high |
| Tulip Tree | Liriodendron tulipifera | Trees | May–Jun | high |
| Trailing Blackberry | Rubus ursinus | Shrubs & Vines | May–Jun | medium |
| Himalayan/English Hawthorn | Crataegus monogyna | Shrubs & Vines | May | medium |
| White Dutch Clover | Trifolium repens | Clover & Legumes | May–Sep | high |
| Crimson Clover | Trifolium incarnatum | Clover & Legumes | May–Jun | medium |
| Vetch | Vicia sativa | Clover & Legumes | May–Jul | medium |
| Big-leaf Lupine | Lupinus polyphyllus | Clover & Legumes | May–Jul | low |
| Self-heal | Prunella vulgaris | Wildflowers & Weeds | May–Aug | medium |
| Linden/Basswood | Tilia cordata | Trees | Jun–Jul | high |
| Himalayan Blackberry | Rubus armeniacus | Shrubs & Vines | Jun–Jul | high |
| Snowberry | Symphoricarpos albus | Shrubs & Vines | Jun–Jul | low |
| Red Clover | Trifolium pratense | Clover & Legumes | Jun–Sep | medium |
| Birdsfoot Trefoil | Lotus corniculatus | Clover & Legumes | Jun–Aug | medium |
| Canada Thistle | Cirsium arvense | Wildflowers & Weeds | Jun–Sep | high |
| Phacelia | Phacelia tanacetifolia | Wildflowers & Weeds | Jun–Jul | high |
| Common Mullein | Verbascum thapsus | Wildflowers & Weeds | Jun–Aug | low |
| Queen Anne's Lace | Daucus carota | Wildflowers & Weeds | Jun–Aug | low |
| Bull Thistle | Cirsium vulgare | Wildflowers & Weeds | Jul–Sep | medium |
| Fireweed | Chamerion angustifolium | Wildflowers & Weeds | Jul–Aug | high |
| Yellow Star-thistle | Centaurea solstitialis | Wildflowers & Weeds | Jul–Sep | medium |
| Canada Goldenrod | Solidago canadensis | Wildflowers & Weeds | Aug–Oct | high |
| Douglas Aster | Symphyotrichum subspicatum | Wildflowers & Weeds | Aug–Oct | high |
| English Ivy | Hedera helix | Shrubs & Vines | Sep–Oct | medium |
A bee forage bloom calendar shows which nectar and pollen plants are blooming in a given area, month by month, so beekeepers can plan colony buildup, splits, and honey harvests around the local bloom.
Every calendar starts with your zip code's specific growing region — its climate, elevation, and local ecology. From there, we use AI trained on horticultural and beekeeping knowledge to work out which nectar and pollen plants actually grow there and when they typically bloom, the same kind of judgment call an experienced local beekeeping mentor or extension agent would make, just automated so any US zip code can get a calendar in minutes instead of years of local observation. Each calendar typically covers 25-40 plants across trees, shrubs and vines, clover and legumes, and wildflowers, plus the area's named honey flows. We keep the exact generation process under wraps, but the goal is always the same: real, locally-grounded bloom timing instead of generic national averages.
The region-specific bloom timing, honey flows, and beekeeping notes are produced by an AI system drawing on general horticultural, ecological, and beekeeping knowledge, applied to your area's specific climate and geography — rather than looked up from a single official bloom-timing database, since no such nationwide dataset exists at this level of local detail. The one exception is the calendar's crop rows (corn, soybeans, almonds, and similar commercial crops), which are grounded in real USDA data instead — see the next question.
Crop rows are different from the rest of the calendar: instead of AI general knowledge, they're grounded in real USDA agricultural data. We look up your zip's US county and pull that county's actual crop acreage from the USDA National Agricultural Statistics Service (NASS) Quick Stats survey and agricultural census — the same data ag extension offices use. AI is only used to fill in each crop's typical bloom timing and forage value to bees; it can't add a crop that USDA data doesn't show is actually grown in your county. Click any crop row in the calendar to see its acreage figure and a link to verify it directly on USDA Quick Stats. This is US-only and applies only to the "Crops" category — the tree, shrub, clover, and wildflower rows are still AI-estimated as described above.
A nectar dearth (or dearth period) is a stretch of the year when little or no medium-to-high value forage is blooming. Colonies may need supplemental feeding during a dearth to avoid starvation or robbing behavior.
A honey flow (or nectar flow) is a period when nectar is abundant enough for a colony to produce surplus honey beyond what it needs to survive, often tied to a specific major regional bloom like clover or black locust.
Bloom timing is generated from regional climate and ecology data and is intended as a general planning reference. It may not perfectly match a specific microclimate, so it's worth cross-checking against your own field observations.
Yes. Enter any US zip code to get a free, printable bee forage bloom calendar — no signup required.