Photos thanks to Paul Westervelt, Saunders Brothers Inc.

2019 Perennial Plant of the Year®

The Perennial Plant Association has awarded the title Perennial Plant of the Year® 2019 to Stachys ‘Hummelo’. Stunning in massed plantings, and popular with designers, this late June-July bloomer is as trouble-free and dependable as it is eye-catching. 

Selected and introduced by famed German grower Ernst Pagels in the late 1990’s, this perennial further gained popularity as it was used by renowned designer and plantsman Piet Oudolf in some of his signature works. “Hummel” means “bumblebee” in German –  appropriate, as Ernst observed many pollinators visiting the flowers. The cultivar name also honored Ernst’s close connection to Piet and his nursery and home at Hummelo, Netherlands. 

Stachys ‘Hummelo’ and related cultivars go by the common name of betony or woundwort. Stachys is in the mint family (Lamiaceae) with its characteristic opposite leaves and square stems. The genus also includes lamb’s ear – Stachys byzantina – known for its woolly silver leaves.  However ‘Hummelo’ features basal rosettes of ovate, glossy, bright green leaves. Tiny, two-lipped, rose-lavender flowers appear in dense spikes atop mostly leafless flowering stems, rising well above the foliage to 1 ½ to 2 feet tall in summer. Clumps will spread over time to form a dense ground cover. It is valued for its crinkled foliage and long display of prolific flowering spikes. 

As previously noted, Stachys ‘Hummelo’ received the highest rating out of 22 Stachys taxa in a comparative study by Richard Hawke, Plant Evaluation Manager of the Chicago Botanic Garden. Exceptional qualities included reblooming without deadheading, no observed reseeding, and outstanding uniformity.

The nomenclature of ‘Hummelo’ is not straightforward. Some resources, such as the Naamjilst and IPNI refer to monieri as the specific epithet (some sources spell it as monnieri). Many others list it as Stachys officinalis ‘Hummelo’,  including the Royal Horticulture Society, Missouri Botanical Garden, and Allan Armitage’s Herbaceous Perennial Plants: A Treatise on Their Identification, Culture and Garden Attributes. Additional synonyms include Stachys macrantha ‘Hummelo’.  The World Checklist of Selected Plant Families, published by The Royal Botanic Gardens, and the  Euro+Med PlantBase describes S. monieri as a “misapplied name” for the species in general and Betonica officinalis as a basionym (original name given a taxon). To further the confusion, a number of European nurseries now list it as Stachys pradica ‘Hummelo’. Regardless of nomenclature, we all agree Stachys ‘Hummelo’ is an outstanding plant! 

Photos thanks to Tony Post and Janet Draper.

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PLANT DATA

Hardiness
USDA Zones 4 to 8

Light
Full sun to part shade

Soil
Well drained soil; water as necessary

Maintenance
Spreads slowly by creeping rhizomes. May benefit from division every few years. Strong stems and seed heads add to winter interest. Considered deer-resistant!