Geranium macrorrhizum


Hi – I live in a wooded area in the countryside near Orangeville so zone 4b. Have this geranium growing successfully in some parts of the garden. Two years ago, took out lawn and replaced with the geranium. Did well year one, less so year two. This year (year 3), lost a lot of plants over the winter. Growing in damp part shade. The plants along the edge by the driveway are growing well, the ones in the middle areas suffering dieback, roots are sitting on top of soil. In the attached photo, it’s the area on the left and the area at the top of the photo. Not sure if due to less winter snow, or leaves lying thickly on them during winter. What might the issue(s) be? What will be the best way to revive the area and get the plants to thrive? Thank you


Geranium macorrhizum or big root geranium is generally a workhorse in the garden, with it filling a space with interesting foliage and pretty little flowers held aloft for all to see.

From your description and picture it seems that there may be a few issues at play here, see below.

  1. Water is vital for these plants and they like a good thorough soaking at least once a week.  My questions would be – are they regularly watered that often? and, were they watered right up until the ground froze last fall?
  2. Snow cover was scarce last winter which means these plants didn’t have an insulating blanket to protect them from the cold winter temperatures and drying wind.
  3. Again, snow cover – due to the lack of it, there was a dearth of moisture in the soil this spring and plants were parched starting the growing season.
  4. Freeze thaw cycles can often make plants heave out of the ground.
  5. Leaves can be an issue if they are thickly covering a flower bed for long periods of time and plants struggle to break through in the spring. When they finally do, they then reach for the sunlight.  When you clear the leaves off, some of the little roots can be seen growing within the leaf material above the soil surface.
  6. Division – it may be time to take a look at the plants you have and see if some of the older specimens need to be dug up and split, with the healthiest ones being replanted.
  7. Soil conditions may currently need to be amended with the addition of more organic matter which will not only help nourish the plants but will also improve soil structure and retain moisture.  Organic matter can be well rotted sheep manure, worm castings or good compost.
  8. A one to two inch layer of mulch spread on the bed will also cut down on moisture loss and help suppress weeds.

Hope this helps.