Learn how to grow a unique container garden full of plants that prefer damp soil.
If you have no space for a bog garden but would like to grow some of the plants that prefer damp soil, create a container display. Simply plant up a large, nonporous pot — made from glazed earthenware, synthetics or galvanized steel — with your favorite plants to perk up a shady patio or poolside.
When to Start: Late spring
At Its Best: Early to late summer
Time to Complete: 2 hours
Select a large nonporous container and make sure it has a drainage hole; drill one if it doesn't. Line the container with a thick plastic sack, such as an old compost bag. With a fork, pierce a few small holes around the sides of the sack, about 2 in. (5 cm) from the bottom.
Fill the base with 3 in. of gravel, which will prevent soil from clogging the drainage holes around the sides and create a water reservoir at the bottom of the pot. Then add a layer of soil-based potting mix with some well-rotted organic matter.
With the plants still in their pots, check that they will sit at least 2 in. below the rim of the pot when planted. Then water the plants, and remove them from their pots. Place them on the layer of potting mix, and fill in around them carefully with more of the mixed soil and organic matter.
Firm in the plants, water well and add a mulch of organic matter. Set the container in a partially shaded area and water frequently. In mild climates, reduce watering in winter to prevent the soil from freezing. In colder areas, move the pot indoors to a bright spot. In spring, replace the top 3 in. of compost with fresh material. Add slow-release fertilizer.
Large containers are ideal for bog plants because they hold more soil and water, and provide the best conditions for good growth.
Any plants that like boggy soil can be added to a container display, as long as you match the size of the pot to your plants. Check plant labels carefully for height and spread. For example, the gigantic leaves and stems of an imposing giant rhubarb will need a large pot to support them, while a group of primulas will be happy in a smaller container.
Excerpted from How to Grow Practically Everything
© 2010 Dorling Kindersley Limited