Balsam (Impatiens balsamina), also known as garden balsam or rose balsam, is a popular annual garden plant. Originating from India and Sri Lanka, it is favored for its vibrant blooms in shades of pink, red, purple, white, and orange.
Growing Balsam
Balsam plants thrive in specific conditions that support vigorous growth and prolific flowering. Providing the right environment ensures a healthy and visually appealing display.
Light Requirements
Balsam plants flourish in full sun to partial shade, requiring at least 4 to 6 hours of direct sunlight daily. In regions with intense summer heat (USDA hardiness zones 8+), afternoon shade prevents wilting and leaf burn. While they tolerate full sun with consistent moisture, partial shade often encourages optimal blooming and denser growth.
Soil Preferences
Well-draining soil rich in organic matter is ideal for balsam plants. They prefer a slightly acidic to neutral pH (6.0-7.5). Incorporating compost or well-rotted manure improves fertility and drainage, especially in heavy or clayey soils.
Watering Needs
Consistent moisture is important for balsam plants, as they are not drought-tolerant and quickly wilt if the soil dries out. Water deeply once or twice a week, adjusting frequency based on weather and soil type. Container plants may need daily watering. Avoid overwatering, which can lead to root rot and fungal diseases.
Temperature and Humidity
Balsam prefers warm temperatures, with optimal growth between 68-75°F (20-25°C). They are sensitive to frost and will not survive below 32°F (0°C), making them suitable for summer growing seasons or as indoor plants in colder climates. While they appreciate high humidity, balsam plants tolerate moderate humidity if soil moisture needs are met.
Fertilizing
Regular fertilization supports abundant growth and flowering. A balanced liquid fertilizer (e.g., 10-10-10) applied every two to four weeks during the active growing season provides necessary nutrients. Alternatively, incorporate a slow-release granular fertilizer into the soil at planting or when plants are at least two inches tall. Nitrogen promotes leafy growth, phosphorus aids root and flower development, and potassium enhances overall plant vigor.
Pruning and Deadheading
Extensive pruning is not typically required. Pinching back young balsam plants (about 4 inches tall) encourages bushier growth and more branching. Remove any diseased or damaged stems to maintain plant health. Deadheading spent blooms and removing developing seed pods promotes continuous flowering by redirecting the plant’s energy into new flowers rather than seeds.
Propagating Balsam
Balsam plants are readily propagated, primarily through seeds, though stem cuttings are also a successful method. Seed propagation is the most common way to grow new balsam plants.
Seed Propagation
Sow seeds indoors six to eight weeks before the last spring frost for an early start. Lightly press seeds onto the surface of moist seed-starting mix, as they require light for germination and should not be covered deeply. Germination typically occurs within 1-2 weeks in a warm, bright location.
Stem Cuttings
Stem cuttings offer another viable propagation method. Select non-flowering stems 4-6 inches long, taking the cutting below a leaf node. Remove lower leaves and plant in a well-draining potting mix. Keep soil consistently moist and place cuttings in indirect sunlight; roots generally develop within 2-4 weeks. Once rooted, transfer new plants to larger containers or the garden.
Common Balsam Issues
Balsam plants can encounter issues related to pests, diseases, and environmental stress. Early identification and appropriate responses help maintain plant health.
Pests
Pests like aphids, spider mites, and whiteflies can infest balsam plants. These insects feed on plant sap, leading to weakened growth or discolored foliage. Control methods include applying insecticidal soap or neem oil. Regular foliage inspection helps detect infestations early.
Diseases
Balsam plants are susceptible to fungal diseases, including powdery mildew and leaf spot. These diseases are encouraged by excessive moisture on foliage and poor air circulation. To prevent fungal issues, avoid overhead watering, instead watering at the base, and ensure adequate spacing for airflow. Root rot is another concern, typically caused by overwatering or poorly draining soil.
Environmental Stressors
Environmental stressors can also cause problems. Yellowing leaves may indicate overwatering, underwatering, or a nutrient deficiency. Leggy growth (stretched stems with sparse foliage) often signals insufficient light. A lack of blooms can result from inadequate light, insufficient nutrients, or allowing seed pods to form, which signals the plant to stop producing flowers. Wilting, while sometimes a sign of underwatering, can also occur under intense heat.