Geraniums (Pelargonium spp.) are prized container plants, valued for their vibrant blooms, fragrant foliage, and general resilience. When selecting companion plants for a mixed container, it is essential to consider the geranium's own preferences to ensure a harmonious and thriving arrangement. From a botanical perspective, successful companions will share similar cultural needs and offer complementary physical and ecological benefits without becoming competitive.
Geraniums possess an upright or slightly mounding growth habit with flower clusters held atop sturdy stems. Ideal companions will contrast or complement this form without overwhelming it. Low-growing, sprawling, or cascading plants are excellent choices as they fill the base of the container and spill over the edges, creating a lush, full appearance. Plants such as sweet potato vine (Ipomoea batatas) with its vigorous trailing habit, or creeping herbs like oregano and thyme, provide a textural mat that highlights the geranium's vertical elements. Conversely, adding a tall, spiky element like dwarf fountain grass (Pennisetum) can add architectural interest behind the geraniums, creating a dynamic and layered composition.
The most critical factor for a successful container combination is aligning the plants' fundamental needs. Geraniums thrive in full sun, requiring at least six hours of direct sunlight daily to bloom profusely. They prefer well-draining soil and like to dry out slightly between waterings, being susceptible to root rot in constantly soggy conditions. Therefore, all companion plants must be equally sun-loving and drought-tolerant. Drought-resistant annuals like verbena, lantana, and angelonia are perfect partners, as they flourish under the same bright, warm conditions and require similar watering regimes. Avoiding moisture-loving plants like impatiens or fuchsia is crucial, as their need for consistently damp soil would quickly lead to stress and disease for the geraniums.
Companion planting can also serve functional roles. Many geraniums, particularly scented varieties, are known to naturally repel certain pests like Japanese beetles and leafhoppers due to their distinctive aroma. Amplifying this effect by including other aromatic plants can create a protective container garden. Herbs are outstanding companions in this regard. Rosemary, with its upright woody stems and needle-like leaves, shares the same love for sun and excellent drainage while its strong scent confuses and deters pests. Basil can also be a beneficial partner, and its flowers will attract pollinators. Adding nectar-rich flowers like salvia or catmint (Nepeta) will draw in beneficial insects such as bees and predatory wasps, which help pollinate the garden and control pest populations.
While color schemes are a matter of personal preference, considering foliage is key to a visually appealing container that remains interesting even when blooms are sparse. Geraniums often have rounded, sometimes zonally marked leaves. Pairing them with plants that have finely textured, dissected, or colorful foliage creates contrast and depth. The silvery, fuzzy leaves of dusty miller (Senecio cineraria) or licorice plant (Helichrysum petiolare) provide a stunning neutral backdrop that makes geranium flower colors pop. Similarly, the deep purple leaves of Persian Shield (Strobilanthes dyerianus) or the bright chartreuse of a golden sweet potato vine offer a dramatic color contrast that can be as impactful as the flowers themselves.
