How to care for plants in wet soil

Plants that grow in wet soil need some extra care and attention. Here are a few things to keep in mind when dealing with this issue.

Not only does wet soil drain slowly initially, but it is easily compacted by footsteps or even the pressure of pounding rain. To address both of these problems, consider building raised beds or natural-looking berms in a wetshade garden. Plants appreciate the extra root space and improved drainage created when a bed is a few centimetres above surrounding moisture-laden soil.

• You can construct raised beds from various materials, including boards, landscaping timbers, brick, stone, or concrete blocks.
• In a wet site, it's a good idea to excavate a few centimtres of soil first, and then line the base of the bed with an 7.5-centimetre-deep (three-inch-deep) layer of gravel.
• The gravel helps drain away excess water and forms an oxygen-rich zone for roots.
• After installing the frame, fill the bed with native soil mixed with compost and sand to further improve its texture and drainage.
• For a more natural appearance, build shallow berms using the same techniques described above.

Whether you are simply making minor contour changes in your wet site, such as making a path, or taking on a larger project, such as constructing raised beds, it's important to work when the soil is relatively dry. Digging in very wet soil is unpleasant, and the soil tends to compact into hard clumps. A care-free reality is that naturally fertile soil that stays constantly moist may not require deep digging or the addition of soil amendments to make it hospitable to plants.

• In wet soil, simply place plants into planting holes rather than cultivating a large bed.
• Whenever you are working in a damp or wet area, keep a pair of short boards handy to use as standing platforms while you plant, weed, or trim your garden plants. The boards will keep mud off your shoes and distribute your weight, reducing soil compaction.
• Having two boards, so that you can stand on one while moving the other to your next position, makes it easy to move between closely spaced plants without stepping on soil.

Many plants that thrive in moist conditions have shallow roots. Surface roots reduce the risk of root rot, because they grow where air is available and soil is likely to dry periodically. But having all the roots near the soil's surface makes them vulnerable to drought damage.

• Protect roots by covering the soil around shady plants with a moisture-retaining organic mulch, such as compost or leaf mold.

Building raised beds of wood is common, but in many areas even treated wood eventually becomes termite bait.

• Using a new material called plastic lumber, which is used for decking, solves this problem. Because it's made from a blend of recycled plastic and sawdust, it's also moisture resistant.