Some of the most fabulous plants will only grow in soil that is permanently moist, and even if you don’t have a boggy area in your garden, it is quite easy to create one. This type of planting looks particularly natural next to ponds or among trees, but can be equally effective in any part of the garden.
When to start: Anytime.
At their best: Summer.
Time to complete: 2 days.
You will need: Garden hose, pond liner, bricks, gravel, well-rotted organic matter – such as manure or garden compost, topsoil, perforated hose, scissors, rake, fork, spade, bog plants.
Dig out border
Next to your pond or other suitable area, use a garden hose to make a curved and natural outline for your bog garden. Dig it out to a depth of about 24in (60cm) and keep the soil.
Place liner and stabilize
Lay the liner in the hole and push it into the corners. To hold it in place, overlap the edges of the hole with at least 12 in (30 cm) of liner, and weigh it down with bricks. Make sure the liner is not pulled tight or else it could rip when filled.
Perforate liner with fork
Although you want the soil in your bog garden to be moist, it should not be completely saturated or it will lack oxygen, which is vital for healthy plant roots. To provide some drainage, pierce the liner with a garden fork at 3 ft (1 m) intervals.
Cover base with gravel
To ensure that the drainage holes do not become blocked over time, causing the soil in your bog garden to stagnate, cover the liner with a layer of gravel or coarse grit. A depth of about 3 in (8 cm) thick should be sufficient.
Trim edge of liner
Fill the bog garden with the soil you excavated when digging the hole, together with some well-rotted organic matter, and press it down. This will settle the liner into its final position. Use sharp scissors to cut any visible excess liner from around the edges.
Place perforated hose around perimeter
A perforated hose, which allows water to seep out slowly, will make it easier to keep your bog garden wet during dry periods. Sink it into the soil all the way around the inside edge of the bog garden, leaving just the hose attachment above ground. You can then simply attach a garden hose to it when necessary. Since the hose attachment will eventually be hidden by plants, remember to mark its position in the garden.
Lay your bog plants out in their pots, and when you are happy with the design, plant them so that they are at the same level as in their pots, or slightly deeper. Mulch with organic matter. Keep well-watered until the plants are fully established.
Striking bog plants
The plants that thrive in boggy conditions are as varied and colorful as any other group, and there are many attractive effects you can create by choosing carefully. Several have impressive and boldly shaped foliage for maximum drama, including giant rhubarblike Gunnera, hand-shaped Rodgersia, and golden-leaved Carex. Others, such as Iris sibirica and Primula japonica, bring a more refined and delicate beauty to your bog garden.