Flowering Times Calendar

Flowering Times Calendar

Be on the lookout for invasive plants flowering in the Sea to Sky!

Many plants flower throughout the year, but did you know some of them are invasive?  Here’s a helpful guide to flowers that you may see on your adventures!

These are in no way the only invasives flowering during each month, but rather a fun highlight of interesting flowers that may catch your eye! These species flower across a range of months, but you are more likely to see them these months.

Report any sightings of these species in the Sea to Sky.


In March, you might find Spurge Laurel (Daphne laureola) along roadsides and moist wooded areas. Meanwhile, Common Periwinkle (Vinca minor) escaped from gardens and creates a thick ground cover and English Holly (Ilex aquifolium) shrubs thrive in forest understories.


  • Spurge Laurel is poisonous and contains a sap that causes skin rashes. Do not remove without following proper handling measures!  Call SSISC if you spot Spurge Laurel anywhere in the Sea to Sky region.
  • Due to sharp leaves, SSISC recommends wearing gloves when handling English Holly. English Holly berries are poisonous; DO NOT EAT.

Report any sightings of Spurge Laurel, Large Periwinkle, or English Holly in the Sea to Sky region.


In April, roadsides turn yellow with Scotch Broom (Cytisus scoparius) flowers. Meanwhile, Yellow Lamium (Lamium galeobdolon) covers trails and grounds, and Himalayan Blackberry (Rubus armeniacus) thickets adorn their brambles with small white flowers.

CAUTION: Due to sharp thorns, SSISC recommends wearing sturdy leather gloves, long sleeves, and pants when handling Himalayan Blackberry.

Report any sightings of Scotch Broom, Yellow Lamium, or Himalayan Blackberry in the Sea to Sky region.


In May, Butterfly Bush (Buddleja davidii) begins to flower, escaped from local gardens.  Meanwhile, Mountain Bluet (Centaurea montana) bursts in meadows and Giant Hogweed (Heracleum mantegazzianum) towers over all.

CAUTION: Giant Hogweed contains sap that causes blisters and chemical burns when it comes in contact with eyes, skin, and the respiratory system; contact SSISC immediately to remove this plant.

Report any sightings of Butterfly Bush, Mountain Bluet, or Giant Hogweed in the Sea to Sky region.


In June, Yellow Flag Iris (Iris pseudacorus) lines ditches and waterways, escaped from nearby gardens. Meanwhile, Common Bugloss (Anchusa officinalis) sprouts up in disturbed areas and Morning Glory (Convolvulus arvensis) tightly binds to fences and anything else close enough for it to latch on to.


  • Yellow Flag Iris may cause skin irritation; SSISC recommends wearing gloves when handling.
  • Morning Glory seeds can be toxic if ingested in large quantities.

Report any sightings of Yellow Flag Iris, Common Bugloss, or Morning Glory in the Sea to Sky region.


In July, Blueweed (Echium vulgare) blossoms in pastures and ranges, crowding out important crops and animal feed. Meanwhile, Foxglove (Digitalis purpurea) and Dalmatian Toadflax (Linaria dalmatica) burst along roadsides and in fields.


  • Foxglove is highly toxic to humans and animals; can cause serious illness or death if ingested.
  • Dalmatian Toadflax may be toxic to cattle if consumed.

Report any sightings of Blueweed, Foxglove, or Dalmatian Toadflax in the Sea to Sky region.


In August, Himalayan Balsam (Impatiens glandulifera)‘s policeman’s helmet-shaped flowers bloom in moist, shaded environments. Meanwhile, Flowering Rush (Butomus umbellatus) blooms along the shorelines of lakes and rivers, and Night Flowering Catch Fly (Silene noctiflora) can be found in fields and other disturbed areas.

Report any sightings of Himalayan Balsam, Flowering Rush, or Night Flowering Catch Fly in the Sea to Sky region.


In September, clusters of Common Tansy (Tanacetum vulgare), Tansy Ragwort (Jacobaea vulgaris) and Chicory (Cichorium intybus) pop up by roadsides, creating showy bursts of yellow and blue.


  • Common Tansy may be toxic to humans and cattle if large quantities are consumed.
  • Tansy Ragwort may be toxic to animals and cause liver damage if consumed.

Report any sightings of Common Tansy, Tansy Ragwort, or Chicory in the Sea to Sky region.