Rain Gardens: A Beautiful, Eco-Friendly Landscaping Solution

Benefits of a Rain Garden: A Win-Win for You and the Environment

A rain garden is a shallow depression filled with native plants. It is designed to collect stormwater runoff so that more of this excess water can be slowly absorbed into the soil rather than flowing onto streets or walkways.

These are some of the key benefits of rain gardens:

• An aesthetically pleasing way to manage excess runoff during and immediately after heavy rain
• By holding rainwater runoff and allowing it to slowly drain away, rain gardens help to prevent local flooding and control erosion
• Rain gardens act as natural filters, helping to remove pollutants and improve water quality in ponds, lakes, rivers and streams
• All the native plants create an excellent habitat for wildlife, including birds, butterflies and other pollinators
• Reduced need for irrigation compared to a conventional garden, as rain water is retained rather than draining away
• Enjoy a breathtaking garden area without the need to mow or fertilize

How Does a Rain Garden Work?

Rain gardens naturally capture, filter and release rainwater runoff from impervious surfaces such as rooftops, driveways and other areas of hardscaping. Water-loving native plants absorb much of this water. The rest slowly seeps through a layer of sandy soil, filtering out contaminants as it goes. This water slowly replenishes the groundwater supply, keeping soil moisture levels high without the need for irrigation.

Unlike retention ponds, rain gardens are designed to release excess water over the course of a couple of days rather than simply holding it indefinitely. This means they won't become a breeding ground for mosquitos, since they are dry most of the time. Instead, the beautiful native plants will attract beneficial insects such as butterflies and other pollinators.

Rain Garden Planning

Finding the Ideal Location

Before you start digging, it's important to make sure you choose a suitable location for your rain garden. Your rain garden location should be:

• At least ten feet away from any buildings, to prevent water seeping into foundations
• Not within 25 feet of a well or septic tank
• In full sun
• Away from any large tree roots

If you have an existing low area on your property, that's a good place to start, as long as it normally drains within a day after heavy rainfall. Don't pick a location where standing water tends to accumulate. The purpose of a rain garden is to help water drain away, so you need to choose a location where that can happen.

A helpful test to see whether a certain area will work for a rain garden is to dig a hole around six inches deep. Fill the hole with water, and monitor how long it takes for the water to drain away. If it's all been absorbed within 24 hours, it should be a good location for your rain garden. If not, pick somewhere else!

How Big Should my Rain Garden be?

The best size for your rain garden will be determined by the amount of excess runoff you expect it to collect. This is based on factors such as the size of your roof (as this is where most of the excess water will come from in the majority of cases) and the slope of your lawn.

IFAS has instructions here for working out the ideal rain garden size. Or, you could try this size calculator from Three Rivers Rain Garden Alliance.

Choosing the Perfect Florida Rain Garden Plants

For your Central Florida rain garden, IFAS recommends combining flowering plants with a combination of grasses, rushes and sedges. This combination allows each plant's roots to grow in a natural way, without them out-competing each other.

Look for a combination of colors, textures and plant heights for maximum visual appeal. Try to choose plants that bloom at different times for a long-lasting display of color. Add to curb appeal by including a garden bench, trellis or ornamental fencing.

Here are some plant selections for a Central Florida native wildflower rain garden:

Muhly Grass

Muhly grass is a striking native plant that puts on a beautiful display of fluffy pink flower stems during fall. It is tall for a grass, reaching up to five feet in height, and its slender, dark green leaves will add movement and a soft texture to your landscape all year round.

Muhly grass does best in full sun. It is ideal for rain gardens because it can cope with high levels of water but is also somewhat tolerant of drought conditions once established.

Virginia Willow

Virginia willow is a large, upright shrub native to almost all areas of Florida. Its tiny white flowers, arranged in drooping spikes, appear in late winter and bloom through early summer. Its slender, dark green leaves change color in fall. Virginia willow therefore provides visual interest year-round for your native wildflower rain garden.

Virginia willow prefers partial shade, but can grow in full sun too. It does best in moist to wet soils, another reason to include it in your rain garden design. This shrub can adapt somewhat to dryer areas but is not drought tolerant, so you'll need to provide water during prolonged dry spells.

Goldenrod

Goldenrod's prolific display of yellow flowers will brighten up your rain garden from late summer through fall. This herbaceous perennial is easy to care for and thrives in full sun. Goldenrod is known as a butterfly magnet and is a valuable food source for pollinators.

Blue Flag Iris

Blue flag iris, with its distinctive, showy flowers in yellow and purple, puts on its beautiful display in late spring to early summer. Its attractive foliage makes it visually interesting year-round.

Blue flag iris thrives in full sun. It is tolerant of inundation and does best in moist soil. During dry times between rains this plant will benefit from extra watering.

Swamp Sunflower

Swamp sunflower is a fast-growing native perennial that reaches up to six feet in height. Its sunny yellow flowers make a pleasing contrast with its dark green foliage throughout the fall season. Swamp sunflower thrives in full sun and is another popular food source for bees and butterflies.

Finishing and Maintaining Your Rain Garden

Once you've placed all of the plants, you need to add a thick layer of mulch around them. IFAS recommends using 2-3 inches of large-chip, hardwood mulch. Once the mulch is applied, irrigate well. It's important to allow the plants to establish their roots, which requires plenty of water. Irrigate every day for the first two weeks.

During the first couple of years, you'll need to replenish mulch and remove weeds as required. Once established, a healthy rain garden will not need much maintenance. Depending on the plants you've chosen, a little extra water during any dry spells may be required.

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