I am more a fan of the structural shapes of the stems and underground roots/tubers than the ephemeral flowers of Pelargonium. Many species grow in the harshest conditions in poor rocky soils. This harsh habitat makes some Pelargonium (and other genera) ideal for very small pots. When I have extra plants I like to show off the stems and roots and under pot them dramatically to accentuate these features and test their survivability. On retirement I started making bonsai pots for my plants and because of greenhouse space availability smaller seemed like a good idea. So far they seem to do well with this growing style though I’ve only been experimenting for a few years. Some are slower growing with reduced leaf size while some maintain large leaves. This is a fairly new growing style so the long term effects on plant health is not yet fully determined.
At the Jardin Exotique de Monaco.
I didn’t expect small pots to be easy care but interestingly in Seattle conditions care so far has been no more difficult than most full size winter growing plants. For ease of watering I grow them in trays with about a quarter inch of my regular potting mix on the bottom. When watering them the overspray dampens the tray mix. As the potted Pelargonium grow, the roots grow through bottom hole into the damp mix in the tray so need of frequent watering is minimized. When summer dormancy is starting to be apparent they go under the greenhouse benches which is low light but the coolest place for the summer. Flowering is not ideal under these conditions but in very hot climates the small pot size could be a problem with root heating and possibly even drying out too much. For other growers interested in experimenting with this growing style, my growing conditions in Seattle are cool low light winters and short summer with sun and clouds alternating.
The greenhouse can get occasionally hot so these plants spend the summers on the floor under the greenhouse benches so they are cooler and out of direct sun. Most of my winter growing Pelargonium spend dormancy under the benches including those in 4 or 6 inch pots. For the 4 and 6 inch potted ones this is mostly a space issue since summer growers are now on the upper benches. I use a very well draining 80% pumice and 20% organics potting mix. This is the same mix in the small pots. When I tried a rich mix thinking that the small pots would not dry so fast the plants were not happy. Experiment with caution your conditions may be different. It would be interesting to know if small potted Pelargonium would survive in areas with long hot summers.
I wonder if one was not concerned with flowering could the geophytic ones be stored in a dark cool place (garage floor) throughout dormancy?
Seattle WA, USA.