Many municipalities are requiring
homeowners to disconnect their downspouts from the municipal sewer
systems for environmental reasons. Even if your downspout empties
onto your lawn, redirecting it into a “bog” or wetland garden is an
effective water conservation method and an alternative to a rain
barrel as a way to capture rainwater for your garden.
The many impermeable surfaces
(roads, sidewalks, driveways, patios, buildings) in cities prevent
rainwater from being absorbed into the land to recharge groundwater.
Instead, rainwater and snowmelt run off these surfaces into sewers,
picking up dirt, oils, pesticides and other pollutants along the
way. Then, the water entering storm sewers flows out in a
concentrated and often polluted rush at single points along nearby
waterways. This rush of water can cause erosion, wash away
fish-spawning beds and cause other damage to the waterways’
By re-directing storm water from
your roof to your garden, you can reduce that impact. Besides,
rainwater is healthier than municipally-treated water for our
gardens, as some plants are sensitive to chlorine and other
additives. Create a native plant wetland garden at the end of your
downspout and you’ll virtually eliminate the need for watering,
fertilizing, and pesticides.
Your garden will become both an
attraction for pollinating insects like butterflies and bees, as
well as a thing of beauty. Some of the most beautiful and unusual of
our native plants thrive in the wet, acidic conditions that
characterize a bog. Once completed, your bog garden will look like
any other but you will only need to water it during the most severe
droughts. Here’s how to get started:
Outline the shape of your downspout
garden and dig it out to a depth of one meter (3.28 feet.) The
bottom of the plot should slope slightly away from the foundation of
your house to direct excess moisture into your garden and/or lawn.
Line the plot with heavy plastic and
poke a few holes several centimeters (three-quarters of an
inch)above the bottom to allow excess water to drain out. (A bog is
characterized by poor drainage, so don’t go overboard.)
Bog plants like acidic soil, so line
the hole with coir (a more ecologically
sound peat moss alternative) and refill with a mixture of the
excavated soil and other organic materials you have on hand
(compost, pine needles.) Mound the soil somewhat to allow for
settling. Wet the mix thoroughly.
Cut your downspout and attach an
elbow and, if necessary, an extension, to direct rainwater into your
garden and away from your house’s foundation. Most hardware stores
carry an array of downspout extensions.
Add your plants and get ready to
enjoy a beautiful and unusual garden.
What to Plant
Native plants will thrive without further
inputs once established in the right location. If you’re not
sure which plants are suitable for bog conditions in your
location, consult your provincial or state organization
concerned with native plants and biodiversity. Links to
groups across Canada and the US, and around the world can be
found on the Native Plants Crossroads website (see below.)
Many garden nurseries and centers sell
native plants. Before you buy, ask about the source of the
plants. The preferred sources are seeds or cuttings. Avoid
pre-packaged wildflower seed mixes because they often
contain many alien, invasive species.
Never take plants from the wild. Collect
seeds from the wild only with the landowner’s permission.
Take a few seeds from many plants, rather than all the seeds
from a few.
You can also try rescuing native plants from being destroyed
by land development and roadside maintenance. Before
attempting rescue, seek permission of the relevant
Many plants do not transplant well; many
orchid species, for example, have formed a symbiotic
relationship with mychorrizal fungi that cannot be
immediately duplicated in a new site. When digging up the
plants you are trying to rescue, make sure you get the
entire root ball and sufficient soil. If possible, try to
plan plant rescues for cooler, overcast Autumn days.
This article is edited from material prepared by the
North American Native Plant Society
Plant Crossroads, Canadian Museum of Nature
Center for Plant Conservation