Its name may be suitable for Halloween, but the Blood Geranium, aka the Blood Red Cranesbill, Bloody Cranesbill, or Geranium sanguineum, is anything but gruesome. In fact, the name comes from the bright crimson color of the fall foliage, rather than from the flowers or any tendency of the plant to bleed! In fact, Blood Geraniums are excellent plants for Colorado gardens.
Cranesbills are a type of perennial geranium with deeply divided leaves rising from a central point, and colorful flowers ranging from white through baby’s blush to shocking pink. Some flowers have brightly veined petals, as shown in the photo. The plants grow approximately 12 to 18 inches high and spread as wide or wider.
Although they come from Eurasia, all perennial geraniums are easy to grow in Colorado. They can be hardy to zone 3, which includes all but the most frigid mountaintops, as long as the roots are well-drained. (Saturated soil can rot roots.)
Geraniums prefer light or filtered shade to full sun. I find that plants grown with reflected heat tend to wilt on hot days, but perk up again once the sun is off their foliage. Too much shade inhibits flowering, although the foliage will thrive. They’re somewhat on the xeric side, but will require supplemental irrigation during long dry spells. Regular garden watering is fine as well.
Garden soil should have around 5% organic matter, whether you have clay, sand, or loam. In ideal conditions, plants may spread a bit too enthusiastically, but in general geraniums are well-behaved, low maintenance additions to the landscape. It’s best to remove dead foliage in early spring (a garden-gloved hand works well), and plants may be deadheaded to prolong bloom. (Letting seeds mature will result in volunteer seedlings the following spring, but remember that hybrids won’t breed true from seed.)
Blood Geraniums are easily incorporated into the front of a perennial border. A massed planting makes a good groundcover, especially under trees whose leaves filter harsh sunlight. While the plants aren’t deer or rabbit-proof, they recover quickly from browsing. Happily, insects leave them alone.