The scented geranium, often sold commercially as the Citronella plant (Pelargonium citrosum), is a popular choice for outdoor container gardening due to its aromatic foliage. Growing this plant in a pot allows gardeners to place it strategically on patios and decks where the fragrance can be enjoyed. Creating a mixed container planting involves selecting other species that not only complement the Citronella aesthetically but also share its specific environmental requirements, cultivating a successful, cohesive, and visually appealing display from a single vessel.
Essential Growing Conditions for Citronella
The success of any mixed container begins with understanding the cultural needs dictated by Pelargonium citrosum. This perennial thrives best when it receives at least six hours of direct sunlight each day. While it tolerates afternoon shade, insufficient light leads to weak, leggy growth and reduced foliage density.
Matching the soil conditions is important for compatibility. Citronella requires a highly porous, well-draining potting mix, ideally incorporating materials like perlite to prevent compaction. Proper drainage is necessary because the plant is susceptible to root rot if the roots sit in saturated soil.
The plant prefers a watering regimen where the top inch or two of the soil is allowed to dry out completely between thorough applications. This drought-tolerant characteristic means companion plants must also withstand periods of dryness. Plants that demand consistently moist conditions will quickly fail in this shared environment.
Selecting Compatible Companion Plants
Selecting species that mirror the Citronella’s preference for full sun and sharp drainage ensures the long-term health of the entire arrangement. Upright fillers provide vertical structure and bloom color alongside the central Pelargonium. Lantana is an excellent choice, as its continuous flowering habit and tolerance for heat and dryness align perfectly with the needs of the Citronella, and its woody structure provides stability.
Another suitable upright option is Pentas, which tolerates the same environmental stressors while attracting pollinators. These filler plants generally have a mounding growth habit that softens the transition between the central Citronella and the edge of the pot. Using plants with contrasting foliage, such as ornamental grasses or Dusty Miller, can also add textural interest.
For plants that trail over the container edge, often called ‘spillers,’ the goal is to find species that do not require excessive water. Sweet Potato Vine (Ipomoea batatas) is utilized for its vigorous growth and dramatic foliage, which comes in shades of chartreuse or deep purple. Its adaptability to dry soil makes it a reliable partner in a sun-baked container, providing a dense groundcover effect.
Trailing Petunias, particularly the heat-tolerant Calibrachoa types, are also highly compatible choices. These bloom profusely throughout the season and require the same full-sun exposure as the Citronella. Their shallow root systems compete minimally with the central plant, and their ability to handle slightly drier soil conditions makes them a functional and aesthetic complement. Bacopa, with its delicate, small flowers, offers another spilling option that performs well in the same environment, providing a finely textured visual element.
Designing and Maintaining the Container
The arrangement of the selected plants should follow a simple design principle, often termed ‘thriller, filler, and spiller,’ to create a balanced visual effect. The Citronella plant naturally serves as the ‘thriller,’ functioning as the tallest, central element due to its upright growth habit and aromatic focus. It should be positioned in the center of the pot to allow symmetrical placement of the other plants.
Companion ‘filler’ plants, such as Lantana or Pentas, should be spaced evenly around the Citronella to provide volume and color contrast. The ‘spiller’ plants, like Sweet Potato Vine or Calibrachoa, are then placed near the edges, allowing them to cascade over the sides of the container. Proper spacing is necessary to ensure adequate air circulation, which helps reduce the risk of fungal diseases in the dense container environment.
Ongoing care requires adjusting watering habits to accommodate the collective root mass. Instead of watering on a strict schedule, check the soil moisture consistently, watering only when the top layer is dry. Applying a balanced, slow-release granular fertilizer at the beginning of the season provides consistent nutrition without promoting excessive growth. Regular deadheading of spent flowers will encourage continuous blooming and maintain the tidy appearance of the display.