A lesson on geraniums
A note to begin
Happy Father’s Day! Give Dad the gift of time by weeding and mulching the garden for him! Are scapes (flowering stalks) forming on your garlic? Cut them off while they are still in the curly “pig tail” stage and enjoy them sautéed with other vegetables or try them chopped in an omelet. They have a lovely mild garlic flavor. If your spring flowering shrubs have gotten a bit large, now is the time to prune them as they finish blooming. Select several of the oldest stems and prune them out. Cut long stems back to just above a bud. Don’t ever give them a crew cut!
True geraniums
Now that Memorial Day has come and gone, it is the unofficial start to the summer season here on the Cape. For many gardeners, it means that we are hurrying to fill up our ornamental containers, as well as plant annuals and perennials in our landscapes. Everyone loves geraniums, which offer bright color throughout the season. They do very well in our ornamental containers and hanging baskets and are quite popular. But annual geraniums are really not true geraniums. They are actually members of the genus Pelargonium and, while related to hardy geraniums in the overall Geraniaceae family, they are a separate genus. True hardy geraniums belong to the genus Geranium and there are many different species and cultivars available to plant in our gardens.
True geraniums are also called Cranesbill because the seed pod that develops after flowering really does look like the long bill of a crane! They are incredibly adaptable plants and there probably is a species or cultivar to fit almost any landscape situation.
Some prefer partial shade while others like more sun. Some like it moist while others like it drier. Most bloom in late May to late June while others might offer some repeat blooming for a longer period of time. One species is incredibly drought tolerant and even offers some fall color!
Many of the species of true Geranium that we plant in our gardens are from Europe or Asia. There is a native species that has come to rival many of these introduced species. Geranium maculatum, the Spotted Cranesbill, is native to eastern North America and is a reliable clump-former that grows to a height of 12 inches to 24 inches and spreads to about 18 inches. It is called the Spotted Geranium because of the faint spots on its palmately lobed leaves. It blooms in late May into mid-June with lovely pink, upward facing flowers. This spring charmer grows well in a partly shaded location but will tolerate morning sun. If planted in full sun, it will need to be kept moist, as the lovely foliage will begin to turn yellow if allowed to totally dry out.
Another great feature of this plant is that it isn’t attractive to those banes of my hosta – the rabbits! It is also very attractive to both bees and butterflies. Spotted geranium flowers mostly in shades of pink but there is an exception. Geranium maculatum alba has clear white flowers. One cultivar that has done exceptionally well for me is ‘Espresso’, which has chocolate-colored foliage with pink flowers!
If you are looking for something to plant in dry part shade to dry sun, there is nothing better than Bigroot geranium, G. maccrorrhizum. This is a plant that dates back to the 1500s when it was cultivated for its fragrant oil. It is native to southern Europe and it has rather large leaves for a hardy geranium.
The lobed leaves can be up to 6 inches to 8 inches wide, although those on my plants are about 4 inches to 5 inches wide. The foliage is also fragrant – try crushing a leaf! It blooms in early June, having light purple-magenta flowers.
The thick, fleshy roots of this plant enable it to spread and it will form a sizeable clump over time. I have it in three locations in my yard and the oldest planting, dating to about 1998, is almost 5 feet across in each direction! It looks spectacular when in bloom and the clean foliage looks good throughout the season. In late summer into fall the foliage will begin to turn a reddish color and it is quite attractive.
Other benefits of those fleshy roots is they make the plant very drought tolerant as well as preventing weeds from growing underneath. There are several cultivars available including ‘Album’, which has white flowers, and ‘Ingwersen’s Variety’, which has slightly glossier leaves with pale pink flowers. There is also a variegated cultivar which I have yet to track down but sooner or later ‘Variegatum’ will be in my garden.
One of the most oft planted species in American gardens is probably G. sanguineum, with good reason. The common name is the Bloody Cranesbill and it is a delightful small mounding plant. It grows about 9 inches tall and spreads to about a foot wide. It is very adaptable as to its growing conditions and is tolerant of sun or part shade. It has small, deeply divided leaves that are topped with deep magenta flowers in June. It actually prefers full sun and is also drought tolerant. If grown in too much shade it tends to be a bit floppy. While the straight species has the darker flowers, G. sanguineum var. striatum has soft pinkish flowers that have a darker pink stripe on each petal. It is also smaller, only getting to be about 6 inches to 8 inches tall.
There are other cultivars that are named after noted plantsmen. Look for ‘Alan Bloom’, which is a short plant with large magenta flowers, or ‘John Elsley’, which is a bit taller. ‘Alpenglow’ has rosy red flowers while ‘Album’ is white.
One hardy geranium that has become quite popular in recent years is ‘Rozanne’, which was originally found in a garden in Somerset, England. It is thought to be a naturally occurring hybrid between G. himalayense and G. wallichianum ‘Buxton’s Variety’. What makes this plant so special is that it blooms all summer! The sterile flowers are relatively large for a hardy geranium, being about 2.5 inches wide, and it is a lovely blueish purple color with a white throat. It was given the award of ‘Perennial Plant of the Year’ in 2008. ‘Rozanne’ grows to about 18 inches tall and 24 inches wide and it is free from insect or disease problems, as are most hardy geraniums. It starts flowering this month and will bloom until frost which is certainly unusual for a perennial plant!
There are so many other species and cultivars that are available that I could write a small book about them. Some of my favorites that I am growing include G. reynardii, which has been described as temperamental but has grown well for me. It has greyish green, somewhat textured leaves with shallow lobes. The light pink flowers have darker markings on the petals. G. nodosum does well in deeper shade that other hardy geraniums. G. phaeum, which has the common name of Mourning Widow, has very dark purple, almost black, flowers with large leaves that have a purple splotch on them. The cultivar ‘Samobar’ has a large blotch and burgundy flowers. If it is happy it will self-seed and you can give the seedlings to your friends.
Many of our fine local garden centers here on the Cape are well stocked with species and cultivars of this wonderful perennial. Try a new one in your perennial garden this year.