Choosing Rainwater Garden Plants
A rain garden is typically created on a natural slope to collect rainwater from a roof, driveaway or street. Deciding which shrubs, flowers or perennial plants suit this condition the best is an essential part of creating a rain garden. Here are some factors to keep in mind that will help you select the best plants for your garden.
Soil and Sunlight Conditions
Understanding the soil textures and moisture levels can make a big difference in the success of your rain garden. Soil textures can range from sandy to loamy, which can determine the best plants for your garden. Loamy soil is the most versatile and is suitable for a wide variety of rain garden plants. Check whether your soil is acidic or alkaline with a soil tester to understand which plants you should add to your garden.
The moisture levels of a rain garden can vary, ranging from wet centers to dry edges. Dry edges would be suitable for drought-resistant plants like lavender or rosemary, while wet centers require plants that can thrive in standing water, like cattails or water lilies. The sun exposure in your area can be classified as full sun, partial shade and shade; different rainwater garden plants suit each condition.
These factors determine the shape of your rain garden as well; typically, a kidney, oval or teardrop shape works best. Choose a shape based on the landscape and water flow to ensure efficiency. Make sure that the long axis of the garden is perpendicular to the flow of water for best results.
Hardiness Zone
Understanding the hardiness zone of your rain garden can help you determine which rain garden plants can thrive in your location. You can check the USDA Plant Hardiness Zone Map to learn which zone your area falls into. This map considers the average minimum winter temperature and your zip code to provide you with your hardiness zone.
Plant Types
Some of the most common options are native plants that are already adapted to your local conditions or perennials that bloom season after season without the need for replanting. Grasses and shrubs can also be planted in your rain garden; grasses and sedges have deep root systems and prevent erosion, while shrubs and trees can help the smaller plants by regulating moisture in the soil and protecting them from harsh sunlight.
Avoid invasive plants that can damage your rainwater garden and hinder the growth of other plants.
Plants that attract pollinators, birds and other beneficial wildlife can make your rain garden a natural retreat.
5 Best Plants for a Rain Garden
Before choosing which rain garden plant is best for you, check whether they’re for full sun, partial shade or shade conditions. This is highly recommended for a thriving and beautiful rain garden.
1. Bee Balm Plants
Also known as monarda, bee balm plants are about 3–4 feet tall and wide. These rainwater garden plants thrive in full sun and attract hummingbirds and butterflies. They usually grow upright and bloom between late spring and early fall. Bee balm plants are a North American native perennial, give a mint scent and are often found along streams and ponds. Best for zones 3 to 9, these plants boast vibrant colors like pink, white and red.
2. Dwarf Fothergilla
The botanical name for this rain garden plant is Fothergilla gardenii, and just like gardenias, they offer a sweet scent. These white flowers appear before the foliage and require partial shade and open space to grow. Recommended for zones 5 to 9, dwarf fothergilla is a low-maintenance plant that can tolerate wet soil.
3. Daylilies
Daylilies are versatile perennial plants available in tall or dwarf varieties and bloom in colors like yellow, red, pink, purple and white. Based on the variety of daylilies, they can thrive in zones 3 to 8. Some varieties of this rain garden plant remain evergreen or semi-evergreen even in mild winter conditions. They’re drought tolerant and don’t require much maintenance for them to thrive.
4. Rose Mallow
The botanical name for rose mallows is Hibiscus moschuetos, and this is among the best plants for rain gardens due to their upright, bushy habit. They thrive when placed along a mixed rain garden border, in containers or on their own. These perennials usually grow to about 5 feet in height and width and are in bloom from mid-summer to early fall. Recommended for zones 4 to 9, rose mallows boast colors like red, pink, lavender or white and naturally grow in swampy areas.
5. Crape Myrtles
Also called Lagerstroemia, this rainwater garden plant thrives all year round with its vibrant flowers in the summer and lush foliage in the fall. Available in a wide range of sizes, from 2 feet in height to tall trees. Crape myrtles grow well in zones 6 to 10 and require full sun for at least 6 hours a day. Their typical bloom time can range between July and September and display colors like white or shades of pink, purple and red.
Caring for Your Rain Garden Plants
Now that your rain garden is set up with ideal plants, learning how to maintain it becomes important. From watering the plants just enough to making sure the soil conditions are suitable, everything makes a difference for your rainwater garden plants.
Watering
Since your rain garden is designed to soak up natural rainwater, you might only have little work to do in this area. During periods with no rain, supplemental watering might be necessary. Be careful not to overwater the plants, as that causes the roots to rot. The watering technique matters, too; ensure you’re focusing on deep watering for optimal root growth.
Consider investing in a rain gauge, which can help monitor rainfall and understand if additional watering is needed.
Soil Maintenance
While natural soil might be sufficient for the healthy growth of your rain garden plants, certain additional efforts can make them thrive. Add a layer of organic mulch next to your plants to help with moisture retention, deal with weeds and prevent soil erosion. Consider adding natural fertilizers like compost or well-rotted manure to help your plants grow.
Pruning, Weeds and Pests
You might need to prune shrubs to maintain their shape and size while deadheading spent foliage can prevent disease and promote blooming. Weeds can hinder your plant’s growth, so manually remove them in the early stages of growth and apply a layer of mulch.
Preventing pests and diseases involves keeping an eye out for these things and using organic pest control methods to deal with them. Chemical pesticides might contaminate stormwater runoff and harm beneficial insects. You don’t have to worry about mosquitoes breeding in your rain garden since they’re designed to drain water within a day or two.
Setting up your rain garden is easy when you know the best plants for your garden and are aware of how to care for them. Now, all you need to do is plant your rainwater plants and sit back and admire your handiwork.