Rain Gardens

We’ve all the heard the expression, when life gives you lemons, make lemonade. Here’s the horticultural version: when life gives you rain, make a rain garden. Then watch the magic happen with pollinators, butterflies, birds, and blooms.

What Is a Rain Garden?

A rain garden is a depression in the ground, planted with species that can tolerate periods of standing water as well as dry spells. It is usually placed in an area of the lawn that tends to collect water — a low spot or a swale. Sometimes, right under a down spout. It is an attractive, environmentally healthy way to handle some of the pure (and not-so-pure) water that runs off your roof and property.

Compared to a patch of typical lawn, a rain garden allows about 30% more water to soak into the ground. Slowing the run-off can prevent or minimize erosion. The bonus is that as the water is slowed, it percolates through the soil, removing impurities. Some of the pollutants that are carried by storm water run-off are fertilizers, pesticides, pet waste, de-icing salts, heavy metals from roof shingles, leaking fluids from machinery and automobiles, and even sewage from failing septic systems.

Deciding Where to Put Your Rain Garden

Next time it rains, go out with your umbrella and see where the water is going. Watch which direction the water flows, where it is rushing over turf, where it settles. There may already be a depression in the ground where the water puddles. If so, remove the turf, expand the area if you want, and get started.

If water is not collecting anywhere, scout out a spot that will collect water if you dig a shallow depression in the ground – even 6” is enough. Keep it simple. It does not need to be lined with plastic, and you don’t need to bring in soil or gravel. A simple depression in the ground can suffice. You can even put it at the base of your downspout.

It will fill with a few inches of water during rainstorms. If you place additional plants in the path of the water as it runs across your yard into the rain garden, that will help too. In fact, the more lawn you replace with plants the better! But’s that’s a topic for another time.

Designing Your Rain Garden

Your raingarden can be formally edged with stones, or it can blend gradually into the rest of your landscape. Just be sure it is far enough away from the foundation of your home that it does not cause basement seepage problems. Don’t locate it over a septic field.

Since the water in the garden will remain after rainstorms, and then dry out, you will need plants that can take soggy and dry soil. Use all perennials, all shrubs, a few trees, or any combination. Plants in the center will remain the wettest for the longest. Plants on the edges will dry out sooner. Keep this in mind as you select the species you plant.

Consider placing larger and taller plants in the center and the lower growing plants towards the edges — this placement allows allow you to see all the plants, but it is not necessary. The birds and butterflies will find them no matter how you arrange them.

The plants below can tolerate periods of standing water that occur in a rain garden. Take note of whether you have sun or shade in your rain garden, and select the plants to match the sunlight. These are good choices for the wettest areas. They will provide blooms and changing scenery through the seasons. You’ll have the added treat of watching birds, butterflies, and pollinators flit in and out of the plants all year long.

Plants for a Rain Garden

Eastern redbud (Cercis canadensis) flowers in springtime.

Chionanthus virginicus (FringeTree) – Fragrant white fluffy bloom late spring.

Rosa palustris (Swamp Rose) – Brambly carefree rose that sets hips in the fall that are relished by birds. Aggressive spreader, great for a large area.