Hardy Geranium (Cranesbill) Care: Growing True Geraniums
Hardy Geraniums, often called Cranesbills due to their beak-shaped seed pods, are valuable and versatile perennials, not to be confused with the common bedding plants called "geraniums" (which are actually Pelargoniums). True Geraniums form mounds or spreading mats of often attractive, divided foliage and produce charming, cup-shaped flowers typically in shades of blue, purple, pink, or white. They are known for their long bloom season, adaptability, and general ease of care, filling roles from groundcovers to border fillers in sun or partial shade.
Common Types of Hardy Geraniums
This large genus offers options for various garden conditions:
Sun-Loving Geraniums
- G. sanguineum (Bloody Cranesbill): Low, spreading mats; magenta-pink flowers; tough, drought-tolerant (Zones 3-8). Cultivars: 'Album', 'Max Frei'.
- G. 'Rozanne': Popular hybrid; vigorous spreader; violet-blue flowers bloom non-stop (Zones 5-8).
- G. himalayense: Saucer-shaped blue-purple flowers; spreads readily (Zones 4-7).
- G. cinereum: Dwarf alpine type; tight cushions; needs excellent drainage (Zones 5-7).
Shade-Tolerant Geraniums
- G. macrorrhizum (Bigroot Geranium): Excellent groundcover for dry shade; fragrant foliage; pink/white flowers; spreads vigorously (Zones 3-8).
- G. phaeum (Mourning Widow): Nodding, dark maroon/purple flowers; prefers moist shade (Zones 5-7).
- G. maculatum (Wild Geranium): Native; pinkish-lavender flowers; moist woodland settings (Zones 3-8).
- G. nodosum: Glossy foliage; lilac flowers; tolerates dry shade once established (Zones 5-8).
Planting Hardy Geraniums
These perennials are generally easy to plant and establish.
When to Plant
- Spring or Fall: Both are excellent times.
Ideal Growing Conditions
- Light: Varies by species (see types above). Most prefer full sun to partial shade. In hot climates, afternoon shade is beneficial for many types. Shade-tolerant species thrive in dappled or partial shade.
- Soil: Adaptable to various soils but perform best in average, well-draining soil amended with organic matter. Avoid extremes of wet or dry, although some species are quite tolerant.
- Spacing: Space 1-3 feet apart, depending on the mature spread of the variety. Allow room for spreading types like 'Rozanne' or G. macrorrhizum. Good air circulation is helpful.
Planting Technique
Select a spot with appropriate light conditions (sun/shade) and reasonably well-draining soil.
Loosen the soil and incorporate compost or other organic matter to improve structure and fertility.
Dig a hole slightly wider and the same depth as the plant's root ball.
Gently remove the Geranium from its pot. Place it in the hole so the top of the root ball is level with the surrounding soil surface.
Fill the hole with soil, gently firming around the base. Water thoroughly.
Apply a layer of organic mulch around the plant to conserve moisture and suppress weeds.
Watering Hardy Geraniums
- Water regularly after planting until well-established.
- Most prefer consistent moisture during the growing season for best performance, but many established types (especially G. sanguineum, G. macrorrhizum) exhibit good drought tolerance.
- Water when the top inch or two of soil feels dry. Avoid letting the soil become constantly waterlogged.
Fertilizing Hardy Geraniums
- Hardy Geraniums are generally not heavy feeders.
- Amending the soil with compost at planting time is often sufficient.
- If desired, apply a light dose of balanced, slow-release fertilizer in early spring as new growth begins. Avoid over-fertilizing.
Maintenance and Care
Shearing for Rejuvenation
- Many hardy Geraniums (especially 'Rozanne', G. himalayense) benefit from being sheared back after their main flush of bloom (usually mid-summer).
- Cut the entire plant back by about half to two-thirds. This removes spent flowers and tired foliage, encouraging a fresh flush of leaves and often a second wave of blooms.
Deadheading
- Individual deadheading can be done but is often tedious. Shearing is usually more effective for rejuvenation.
Division
- Divide clumps every 3-5 years in spring or fall if they become overcrowded, the center dies out, or you wish to propagate. Dig up the clump, separate into sections with roots and growing points, and replant immediately.
Cleanup
- Cut back dead foliage in late fall or early spring before new growth emerges. Some types have semi-evergreen foliage; tidy as needed in spring.
Troubleshooting Common Problems
Hardy Geraniums are generally robust and healthy.
Powdery Mildew / Leaf Spot
Symptoms and Management
- Fungal diseases sometimes appear, especially in humid conditions or dense shade with poor air circulation.
- Prevention/Control: Provide adequate spacing for air circulation. Choose appropriate species for light conditions. Water at the base. Remove affected leaves. Shearing mid-season often removes infected foliage. Fungicides rarely needed.
Rust
Symptoms and Management
- Orange pustules on leaf undersides.
- Prevention/Control: Similar to mildew/leaf spot - improve air circulation, clean up debris. Remove infected leaves.
Sprawling / Floppy Growth
Possible Causes and Solutions
- Too Much Shade (for sun-loving types): Provide more sun if possible.
- Overly Rich Soil / Too Much Fertilizer: Avoid excessive feeding.
- Natural Habit: Some varieties (like 'Rozanne') are naturally vigorous sprawlers. Allow them room or shear mid-season.
Conclusion
Hardy Geraniums (Cranesbills) are indispensable perennials offering a long season of bloom, attractive foliage, and adaptability to various garden conditions from sun to shade. Easy to grow and relatively pest-free, they make excellent fillers, edgers, and groundcovers. Choose varieties suited to your light and moisture conditions, shear them back mid-season for rejuvenation if needed, and enjoy their reliable performance for years.
