Hardy geraniums are perennial, thriving in the garden without special care or maintenance. They survive in the garden even in freezing weather and do not require overwinter storage as do more tender varieties. Hardy geraniums come in every color but true red and yellow, adding bright hues to the garden throughout summer. Varieties thrive in both full sun and shade, so finding a hardy geranium to fit your landscaping needs is possible.
Check the plant label on the geranium for sun requirements. Prepare a bed that meets these needs. Apply a 2- to 4-inch layer of compost over a well-drained garden bed. Work it into the top 6 inches of soil.
Dig the planting hole to the same depth as the pot the geranium transplant is in but slightly wider. Remove the geranium from the pot and set it in the hole so it is at the same depth. Fill in around the root ball with soil and firm it in place with your hands. Follow the spacing requirements on the label for the particular variety.
Water the geraniums immediately after planting, moistening the bed to a 6-inch depth. Water once weekly thereafter and twice weekly during extended dry periods if the soil begins to dry out.
Lay a 2-inch layer of mulch over the bed and around the plants. Mulch prevents weed growth while also preserving soil moisture.
Cut back the geraniums to about 3 inches high if they become leggy and overgrown at midsummer. Plants will regrow and possibly rebloom. Cut back the geraniums a second time in fall once frost has caused the geraniums to die back for the season.
Add a fresh 2-inch layer of compost each spring when the geraniums begin growing again to replenish nutrients in the soil. Alternately, apply a balanced fertilizer at the rate recommended on then label.