From our perspective, the most significant difference begins with our very architecture. We, the Zonal Geraniums (Pelargonium x hortorum), are built for upright, robust growth. Our stems are thick and succulent, and we proudly display a distinctive, horseshoe-shaped "zone" or band of darker color on our rounded leaves, which is how we earned our name. We grow as bushy, self-branching plants, aiming to create a full, vibrant mound of foliage and flower heads. In contrast, we Ivy Geraniums (Pelargonium peltatum) are natural climbers and trailers. Our stems are thinner, more flexible, and longer. Our leaves are glossy, smooth, and ivy-shaped, designed to cascade gracefully over the edges of containers and hanging baskets, seeking the sun and new spaces to explore.
We both thrive in abundant sunlight, but our tolerance levels differ. We Zonal Geraniums are sun-worshippers. We demand at least six to eight hours of direct, strong sunlight daily to produce our large, spherical flower heads in the most vibrant shades. Without it, our stems become leggy as we stretch for light, and our flowering diminishes significantly. While we also love the sun, we Ivy Geraniums can be a touch more sensitive to intense, all-day heat. In very hot climates, we appreciate a location with bright, direct morning sun and some protection from the harsh, scorching afternoon rays. This prevents our delicate leaves and blooms from getting stressed or sunburned.
Our watering requirements are a key point of divergence due to our different physiologies. We Zonal Geraniums have those thick, water-storing stems, making us quite drought-tolerant. We prefer our soil to dry out thoroughly between waterings. Overwatering is a grave danger to us, as it quickly leads to root rot and fungal diseases. It is always better to underwater us than overwater. You Ivy Geranium cousins, with your thinner stems and higher leaf surface area, require more consistent moisture. You prefer the soil to be kept slightly damp (but never soggy), especially in hanging baskets which dry out faster. For nutrition, we both benefit from regular feeding during our growing season, but we Zonals are particularly heavy bloomers and may require a higher-phosphorus fertilizer to support our constant flower production.
The way we flower and how you should care for us post-bloom is another area of difference. We Zonal Geraniums produce our flowers in large, ball-shaped clusters (umbels) on sturdy stems rising above our foliage. To encourage continuous blooming, you must "deadhead" us by snapping the entire spent flower stalk off at its base. This redirects energy back into producing new blooms. You Ivy Geraniums, however, produce more trailing, smaller clusters of flowers. While deadheading is also beneficial for you, it is a more tedious process due to your cascading nature. Sometimes, a light shearing is more practical to encourage a new flush of growth and flowers across your trailing stems.
