My Everchanging Garden

Gardening That Grows With Me

Spiraea betulifolia ‘Thor’ (Thor or Tor Spirea)

Height: 60 cm (2 feet)
Spread: 80 cm (2-3 feet)
Bloom: white in early May
Foliage: dense, blue green leaves turn redish in fall

Pluses: very show bloom, foliage is different for spirea, reddish in fall

Thor Spirea is a dense rounded shrub with white flowers in spring. I love the foliage on this spirea. It is larger than the usual spirea foliage, starts out bright green in spring but turns blue-green in summer and then a slight reddish in fall. Densely grouped this makes a nice groundcover or filler plant.

Spirea Tor flowers

White flowers appear on Spirea Tor in spring

After blooming, I prune off the topmost flowers fairly tightly. The remaining flowers do turn brown (as do all white blooming shrubs unfortunately) but tucked inside the plant they do not deter from the otherwise nice shape and colour of this plant. Remove twiggy growth on old plants every few years to encourage fresh new growth in order to encourage more blooms.

Garden Location: Kitchen Patio Garden and Front Entrance Gardens.


  1. Carole on

    My Thor Spirea bush has white flowers that are quickly turning brown. Should I deadhead these brown flowrrs

    • Everchanging Gardener on

      White flowers do that – they fade to brown which is why I’m not a fan of white generally. You can trim spirea after blooming, you’ll get nice new compact growth just don’t wait too long or you will have no flowers next year. My Thor unfortunately have now been torn out as the area they were in became too shady. I may try some in another spot eventually.


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