A Guide to Bog Gardens

By Julie Christensen

What comes to mind when you think of the word, bog? The dark, forbidding landscape of Victorian tales like Wuthering Heights, perhaps? Or maybe the wetlands of the Florida Everglades? Natural bogs occur in both humid and cold areas. In nature, they take hundreds, and even thousands of years, to develop. A bog builds up when sphagnum peat moss grows in a pond or lake, eventually filling it and creating a soggy wetland. Sometimes bogs occur when moss covers a low-lying damp area so that moisture in the soil can’t escape.

Whatever the mechanism for growth, bogs provide a very specialized growing environment. The soil is highly acidic and nutrient poor. Only certain types of plants – such as carnivorous plants – can grow in a bog. Bogs are also home to numerous insects, birds and other wildlife.

In recent years, gardeners have become interested in bog gardens for the home landscape for several reasons. A bog makes a soft, natural transition from a pond to the yard. Bogs also allow the adventurous gardener an environment to grow exotic plants. Building and maintaining a bog garden takes some extra work and specialized care. Read on to find out if a bog garden is right for your landscape.

Choosing a Site

Like any other gardening venture, bog gardens work best when you choose a site that is naturally amenable to a bog garden. Low-lying areas where the soil is already soggy work well. Areas next to a pond are also ideal. Many bog plants need full sun to perform well, so don’t think you have to choose a shady site. However, gardeners in dry, arid climates will have trouble keeping a bog moist.

Once you’ve chosen the site, dig an area for your bog. The bog should be at least 3 feet in diameter and 18 to 3 feet deep. Excavate the soil and place it in a tarp. Once you’ve dug out the area, cover the soil with a hard plastic liner, plastic or even clay from the soil. Mix the clay with water and spread it. Tamp it into place with your hands or a mallet to form a sturdy shell.

Although the bottom of the bog should be water-tight, water must drain from the top 12 inches of the bog garden. Dig or drill holes in the plastic liner 12 inches from the soil surface. Now it’s time to fill in the bog. Amend the excavated soil with a combination of peat moss and sand at a rate of one part soil to one part amendments. These amendments create the acidic, low nutrient environment bog plants need.

Bog plants

Now it’s time to plant the bog. Many plants can grow in a bog setting, from common day lilies and daffodils, to native grasses and carnivorous plants, such as pitcher plants. Try heather, which grows natively on the boggy heaths of England and Ireland, or monkshood and yellow waxbells.

Harvesting carnivorous plants from their native wetlands is an undesirable and potentially illegal activity that disturbs the natural ecosystem. Buy carnivorous plants from a reputable nursery and make sure they were commercially propagated, rather than harvested.

Maintaining your Bog Garden

The most important part of maintaining a bog garden is to keep the soil consistently moist. Integrate a drip system or other watering system when you build the bog. Some specialized blogs can only use rainwater or distilled water. Remove the weeds regularly and divide plants when they become crowded.

Bogs encourage butterflies, amphibians and birds to your garden, but they’re also the perfect breeding ground for mosquitoes. If your bog sits next to a pond, stock the pond with fish to help reduce mosquito populations. You may also need to incorporate a natural pest control product such as Bacillus thuringiensis into your bog garden.

To learn more about bog gardens, visit the following links:

Creating a Simple Bog Garden from Washington State University.
Building a Bog Garden from the University of Illinois Extension.

Julie Christensen learned about gardening on her grandfather’s farm and mother’s vegetable garden in southern Idaho. Today, she lives and gardens on the high plains of Colorado. When she’s not digging in the dirt, Julie writes about food, education, parenting and gardening.