Curious to know why the leaves on my geranium phaeum (“raven”) are completely crumpling and curling in on themselves.
I do have leaf tiers on my hydrangeas and monardas but there is no visible bugs/silk/caterpillars on the geraniums. They simply seem to be recoiling and curling in.
They’re in a spot where the sun will hit them in the morning but by 2/3 they’re are in shadow. The soil is dry & Sandy.
Thank you for contacting the Toronto Master Gardeners concerning your Geranium phaeum ‘Raven’.
This is a beautiful clump forming herbaceous perennial which produces dark purple flowers from late spring to early summer.
The fact that you do not see any pests or diseases on the leaves of your plant leads me to believe that what you are seeing is due to environmental factors. The Royal Horticultural Society states that this variety grows in both sun or shade in moist but well-drained soil but does best in shaded areas. I believe your leaves are curling up is because the soil is not retaining enough water and nutrients.
You can improve your soil texture with the yearly addition of organic matter or compost. This will not only improve the soil’s moisture retention it will also improve the soil porosity. These yearly amendments should be added to the soil surface, allowing existing microorganisms to incorporate the additions naturally, while preventing disturbance of the natural soil profile as much as possible.
You should also mulch the area with a couple inches of shredded cedar or pine bark mulch making sure that the mulch does not cover the crown of the perennial. The mulch will help with moisture retention and will regulate the soils temperature.
May 26, 2021