How to Grow Impatiens in Your Flower Garden

There are over a thousand species of impatiens available, but they fall within two primary categories.

1. 1. Standard impatiens: Impatiens walleriana—also known as busy Lizzie or balsam—is one of the most common bedding plants used to decorate public parks and gardens around the world. It's an herbaceous perennial in frost-free climates but is regarded as a half-hardy annual in many parts of the United States (USDA hardiness zones 10 and 11, especially) and other temperate climates. Standard impatiens are available in a variety of colors, grow best in full or partial shade, and can be up to two feet tall depending on the cultivar. The Super Elfin cultivar is a hybrid type that has become the most popular variety of impatien grown around the world.
2. 2. New Guinea impatiens: Impatiens hawkeri—also known as sun impatien due to its higher tolerance for sunlight—is a hybrid variety that produces larger and more vibrant flower colors than standard impatiens. New Guinea impatiens are mildew-resistant and capable of growing up to three feet tall, with foliage that comes in different colors—including green, purple, and bronze. New Guinea impatiens are typically more difficult to grow from seed. One of the newest and most popular types of New Guinea impatiens is the Sunpatien series, which tolerates full sun conditions.

Planting impatiens is a straightforward process as long as you follow a few simple guidelines.

• Plant impatiens outside after the last spring frost. Impatiens plants struggle in cold temperatures, so plant them only when the last spring frost has passed. If you want to get a head start, you can start your seeds indoors nine weeks before the last frost and then transplant the seedlings outside.
• Choose a shady location protected from the wind. Standard impatiens are one of the few flowering plants that grow best in full shade conditions, while New Guinea impatiens typically fare better in partial sun.
• Grow impatiens in fertile, well-drained soil. Impatiens need lots of water, so it's important your soil provides sufficient drainage. If you're planting in a container such as a window box or hanging basket, use a well-drained potting soil or soilless potting mixture.
• Enrich your soil with nutrients. Fertilize your soil with aged compost before planting. This organic matter will provide your impatiens the extra nutrients they need to thrive.
• Space your impatiens close together to incite taller growth. Planting impatiens about six inches apart will encourage them to grow upright. Conversely, if you're planting impatiens as groundcover in a flower bed, space them farther apart—about 10 to 12 inches.

Follow these basic principles to provide the ideal growing conditions for your impatiens and increase the chances of a robust, colorful flower bloom.

• Water regularly to keep your soil moist. About two inches of water a week is a good rule of thumb, but be careful not to overwater. Applying a layer of organic mulch can help the soil retain moisture and prevent impatiens leaves from wilting in hot weather. If you planted your impatiens in a container, they will typically need more water than if planted in the ground.
• Fertilize regularly throughout the growing season. Regular fertilizing helps encourage healthier impatiens flower blooms. Use a water-soluble fertilizer every two weeks according to the instructions. If you used a slow-release fertilizer at planting time, you can apply that same fertilizer again in the middle of summer.
• Prevent pests. Insects aren't a huge problem for impatiens, but red spider mites and aphids may occasionally infest your plants. You can use a garden hose to spray these infestations away, and you can also prevent spider mites by companion planting aromatic herbs—like garlic, rosemary, or chamomile—near your impatiens.
• Prevent disease. Impatiens are vulnerable to root rot disease, the symptoms of which include wilted leaves and brown lesions on the stem below the soil line. Prevent diseased roots by making sure you don't overwater your impatiens. Careful watering also helps prevent mildew. While New Guinea impatiens are mildew-resistant, the standard variety is extremely susceptible to impatiens downy mildew. Symptoms of downy mildew include wilting yellow leaves with white spore. You can prevent powdery mildew by keeping the leaves dry during watering and making sure your plants have sufficient air circulation. If you do discover impatiens downy mildew, remove the infected plants immediately.

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