Pruning is an essential practice for maximizing the display and longevity of geraniums. The plants commonly known as geraniums are actually members of the genus Pelargonium, which are tender perennials grown as annuals in many climates. Proper pruning directs the plant’s energy away from excessive stem growth or seed production, encouraging it to produce more lateral branches and a continuous flush of blooms. By understanding the difference between light maintenance and structural cutting, a gardener can ensure their plants remain dense, healthy, and floriferous throughout the season.
Light Pruning for Ongoing Health and Shape
Maintaining a geranium’s appearance and maximizing its bloom cycle requires frequent, light pruning throughout the active growing season. The simplest form of maintenance is called “pinching,” used to encourage a bushy, compact shape rather than a tall, spindly one. This involves removing the soft, growing tip of a stem, typically the top half-inch to one inch, just above a leaf node where new growth originates. Removing the apical bud causes the stem to branch out and become fuller by activating lower lateral buds.
The other ongoing light cut is “deadheading,” which is the removal of spent or faded flower heads. A geranium will attempt to produce seeds after flowering, a process that uses significant plant resources and signals the plant to slow down bloom production. To deadhead, trace the spent flower stalk, known as the peduncle, down to where it meets the main stem or a leaf joint. The entire stalk should be snapped off cleanly at this junction, and deadheading should be performed regularly as soon as the flower petals begin to shrivel or brown.
Hard Pruning for Rejuvenation and Structure
While light pruning manages ongoing growth, a more substantial technique called “hard pruning” is necessary to rejuvenate older, woody plants or prepare them for overwintering. Geraniums naturally become “leggy” over time, developing thick, woody stems with sparse foliage, which reduces their flowering potential. Hard pruning is performed either in late summer or early fall before the plant is brought indoors, or in late winter to early spring before the new season’s growth begins.
The process involves cutting back the main stems by a significant amount, usually by one-third to two-thirds of their height. For overwintered plants, this cut can be severe, reducing the plant to a framework of stems about four inches (10 cm) tall. Always make the cut just above a healthy leaf node or a point where a new side shoot is emerging; this ensures the plant has a growth point ready to activate. Using sharp, clean shears is important to create a neat slice, which minimizes the risk of disease entry and stimulates a strong burst of new, vigorous growth.
Care After Pruning and Using Cuttings
After a hard pruning session, a geranium requires a period of adjustment to recover and focus its energy on new growth. One essential step is to ensure that all pruning tools are sanitized before and after use, minimizing the transmission of potential plant viruses or fungal spores. Following a significant cut, the plant’s overall water needs are temporarily reduced because a large portion of its leaf mass has been removed. Overwatering a freshly pruned plant can lead to root rot, so the soil should be kept drier than usual until new foliage begins to emerge.
The healthy, non-woody stem sections removed during hard pruning can be used to propagate new plants through stem cuttings. A cutting should be taken from a healthy stem, measuring about four to six inches long, with the cut made just below a leaf node. The lower leaves and any flowers or buds must be removed to ensure the cutting focuses its energy on root production. These cuttings can then be inserted into a well-draining, moist rooting medium, with the bare nodes buried to encourage root formation.