Best hardy geranium varieties from the legendary Rozanne to shade-loving types

The genus Geranium contains hundreds of species and countless hybrids, making it a difficult group for gardeners to navigate. Many widely sold types bloom for a brief two weeks in late spring and then collapse into an untidy heap of exhausted foliage. Rather than cataloging every available option, I have selected a small group of the best hardy geraniums that solve specific garden problems with absolute reliability. These are the plants that earn their space through exceptionally long bloom times, superior weed suppression, or the ability to thrive in deep shade. When you filter out the mediocre performers and the aggressive self-seeders, you are left with a handful of exceptional geranium varieties that belong in almost every temperate garden.

Continuous bloomers for full sun

When selecting a blue-flowered hardy geranium for a sunny location, gardeners usually encounter two dominant varieties. Gardeners have planted Geranium ‘Johnson’s Blue’ for decades, and many older garden guides still recommend it as the standard blue cranesbill. It produces large, clear blue flowers in early summer, but the plant has a fatal flaw in its growth habit. By mid-July, ‘Johnson’s Blue’ typically sways open from the center, leaving a bare patch in the middle while the flowering stems flop heavily onto neighboring plants. It also ceases blooming entirely once the heat of late summer arrives. Because of these structural failures, I consider it a plant that has been entirely superseded by modern breeding.

Geranium ‘Rozanne’ is the modern replacement for those older blue varieties, and it corrects every flaw of its predecessors. This sterile hybrid produces violet-blue flowers with white centers continuously from early June until a hard frost stops it in late autumn. Because it does not produce seed, the plant channels all its energy into generating new flowers and vegetative growth. It has a naturally sprawling habit that allows it to weave harmlessly through the stems of taller shrubs and perennials. ‘Rozanne’ pairs exceptionally well with other long-blooming perennials, sending its blue flowers through the silvery foliage of catmint along a sunny border. The sheer volume of flowers it produces over five months makes it one of the most useful herbaceous perennials in cultivation.

Dependable ground covers for difficult spaces

Most gardeners have areas where the soil is poor, the moisture is inconsistent, and weeds constantly threaten to take over. For these difficult edge spaces, the Geranium cantabrigiense hybrids offer an elegant and permanent solution. Geranium ‘Biokovo’ is my primary selection for this role, forming a dense, weed-proof mat of semi-evergreen foliage that stands only eight inches tall. The leaves contain highly aromatic oils that make the plant completely unappealing to grazing deer and rabbits. In late spring, ‘Biokovo’ covers itself in pale white flowers tinged with delicate pink sepals, creating a soft cloud of color at the front of a border. It spreads steadily by shallow underground rhizomes but remains incredibly easy to control with a single pass of a spade in the spring.

For those who prefer a stronger punch of color in their ground cover, Geranium ‘Cambridge’ offers the exact same rugged constitution as ‘Biokovo’ but produces solid magenta-pink flowers. Both of these varieties excel at softening the hard edges of stone walkways or retaining walls. They tolerate a surprising amount of drought once established, making them highly effective for planting under the eaves of a house where rain rarely reaches. They make excellent alternatives to traditional edging plants, offering a softer appearance than a creeping bellflower while maintaining a much tidier habit throughout the winter months. The foliage often takes on attractive red and orange tints in the autumn, extending their visual interest well past the flowering season.

Selections for dappled light and dry shade

Dry shade under mature deciduous trees is widely considered the most difficult environment in any garden. Geranium phaeum ‘Samobor’ is a specialized cranesbill that has adapted perfectly to these exact conditions. Unlike the sun-loving varieties grown primarily for their large blooms, ‘Samobor’ earns its place entirely through its distinctive foliage. Each deeply lobed green leaf has a clear, dark purple chevron pattern that remains crisp and visible from spring through autumn. The plant does produce small, nodding, dark maroon flowers early in the season, but these are secondary to the persistent architectural value of the leaves. I select this variety specifically because it brings bold texture and color to shadowed corners where very few other perennials will survive.

Geranium endressii ‘Wargrave Pink’ is another excellent candidate for partially shaded areas, though it has a very different purpose than the clumping ‘Samobor’. This is a highly vigorous, spreading geranium that produces an endless succession of bright salmon-pink flowers from early summer into autumn. It will happily colonize the difficult ground beneath large shrubs or tree canopies, knitting itself into a solid mass of green foliage. I include this variety with a specific caveat regarding its aggressive nature. ‘Wargrave Pink’ will quickly overrun delicate alpine plants or slow-growing neighbors, so it must be deployed only in large, empty spaces where you genuinely want a single plant to take over. When given the right job in the right location, it is a highly effective workhorse for the woodland edge.

While all the hardy geranium varieties detailed here excel at their specific garden tasks, Geranium ‘Rozanne’ remains my absolute top recommendation for almost any gardener. The criteria for a truly great garden plant are rigorous, requiring a long season of interest, immunity to common pests, and a growth habit that requires minimal human intervention. ‘Rozanne’ meets all these requirements while providing a volume of continuous floral color that very few plants in any genus can match. Its sterile nature ensures it will never become a nuisance by seeding into unwanted areas, and its sprawling habit unifies a mixed planting by weaving disparate elements together. If you have space for only one hardy geranium in your garden, this tireless violet-blue bloomer is the definitive choice.