Peony ‘Green Monster’ (Swenson Gardens, 2021)
Not loud. Not frilly. Not predictable.
‘Green Monster’ defies expectations — not with sheer volume, but with detail. Its 5" semi-double to double blooms open in pale ivory, infused and streaked with fresh green, especially through the center of the petals. The effect is almost painterly — like a botanical ink wash that changes slightly flower to flower.
Petals are softly ruffled, lightly twisted, and shallowly notched to a frilled edge, forming a loose double overall. Occasionally, pollen-bearing yellow stamens appear. Carpels are typically underdeveloped (usually two, moderately hairy). Fertility remains unknown.
It’s fragrant. It’s upright. And it reaches an impressive 40" without typically needing support. Midseason blooming, it steps into the garden at just the right moment — late enough to feel intentional, early enough to anchor the show.
In the field, it grows with calm precision. In the vase, it’s a conversation starter.
Why You’ll Love It-
Unique ivory blooms with prominent green streaking
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Semi-double to loose double form
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Fragrant midseason bloomer
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Strong, upright stems to 40″
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Collector-worthy but garden-strong
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Cultivar: Green Monster
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Group: Lactiflora
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Originator: Swenson Gardens
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Release Date: 2021
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Country: USA (MN)
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Seedling No.: RAHS 7
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First Bloomed: 2014
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First Propagated: 2014
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Height: 40″ (101 cm)
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Bloom Size: Approx. 5″ (12 cm)
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Bloom Season: Midseason
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Fragrance: Yes
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Fertility: Unknown
Released by Swenson Gardens in 2021, ‘Green Monster’ represents modern hybrid breeding — intentional crosses designed to combine strength, bloom timing, resilience, and distinctive form.
While traditional lactifloras are known for reliability and elegance, hybrids often push form and color boundaries while maintaining strong garden performance. ‘Green Monster’ may look unconventional, but it grows with the dependability serious growers expect.
Unorthodox bloom. Solid horticultural logic.
And yes — it absolutely belongs in the garden.
Photo Credit: Groot and Groot

