Geranium macrorrhizum, more commonly known by the nickname bigroot cranesbill, is a terrific addition to almost any type of garden.
The geranium macrorrhizum can be a suitable ground cover for the gardener who doesn’t have a lot of plants or who wants to maintain a light or casual atmosphere.
This species of plant can also be of use to someone who likes to maintain a formal type of landscape as this variety of geranium can set a great backdrop for more exotic or impressive plants while offering ground cover with a dense root system that works to block out weeds.
Physical Characteristics of Geranium Macrorrhizum
This type of geranium produces the “zonal” flower, which is the most popular form of geranium among gardeners. This is the type of flower that you most likely think of when you hear the word “geranium”.
The macrorrhizum is a little different from other common types of geranium because it grows in a tight but full mass of leaves and flowers.
The flowers of the geranium macrorrhizum are typically pink although they can range from white to medium pink, to very dark pink. Each flower has five petals with long stamens protruding from the center of the flower.
Each flower is only about an inch in diameter which means that this plant isn’t likely to “wow” your guests, but it is a sweet and dainty compliment to an existing garden. You can also expect lots of attention from butterflies with this flower!
The macrorrhizum is considered to be a low-growing plant because it will typically not exceed more than 12 inches in height. One plant, however, can grow at a spread rate averaging about one foot per year, capping out around five feet.
If you need to fill in a three to five foot section of ground and you aren’t in a rush to do so, you would only need to grow two or three of these plants to have complete ground coverage after a few years.
The geranium macrorrhizum is well known among gardening communities as being extremely hardy! It grows in USDA zones four through eight and has a very long bloom period.
It is quite tolerant of cold temperatures—in fact, this species of geranium usually keeps green leaves into the autumn season. The macrorrhizum is a plant that thrives in sunlight.
It will flower and spread in partial shade but performs extremely well if it is exposed to full sunlight.
People who live in zones seven and eight should be warned that this plant can grow so well in these regions that it might actually choke out nearby flowers, shrubs, and trees; which means that it would be better suited to a sparse area.
This type of geranium is also fairly tolerant of drought conditions, so if you live in an area where the summer months can be a little dry, then this flower might be a good choice for your garden! This is also a good choice for anyone who is looking for a simple plant that deer will not eat.
Because this plant is so hardy, it doesn’t have much of a preference when it comes to soil composition or acid content.
As long as the planting site has good drainage and will not retain water often, the Geranium Macrorrhizum should be fine. Choosing an area with sufficient space is important—not necessarily for the geranium but for other surrounding plants as they could be smothered by the strong and sometimes invasive roots of this geranium.
A two foot space would suffice for a single plant, but if you are going to grow more than one geranium then there should be at least a two-foot gap between the plants.
Where to Buy Geranium Macrorrhizum
You can usually find Geranium Macrorrhizum for sale in local garden nurseries or garden supply stores in the early spring. These plants are small to begin with but if the setting is right this geranium will grow quickly.
Avoid plants that appear ill in any way, such as shriveling leaves or petals, severe discoloration, or excessive droopiness.
Your “beginner” Geranium Macrorrhizum should be springy and colorful. Due to its popularity, this type of geranium comes with a cheap price tag and is usually in stock at most garden center when in season.
If you want to choose from a larger selection of geraniums then you might consider making your purchase online. Most online garden nurseries will ship your plant securely and by purchasing your plant online you can compare the price, selection, and shipping times of many different retailers.
Planting the Macrorrhizum
The planting process is very simple. Remove the geranium from its temporary pot and gently massage the excess soil from the roots.
This will also loosen the roots and encourage them to settle and spread better in the planting site. Use a garden spade or shovel to dig a small hole—about double the size of your geranium’s roots.
Throw a bit of dirt back into the hole and place your plant’s roots on top. The top of the roots should rest just below ground level. Fill in the rest of the hole with dirt and be sure to pack