Can garden get too much water? Yes, but these steps will help with garden drainage
With the influx of moisture in the KC metro recently, there has also been an influx of questions along the lines of “How much water is too much water for my plants?” Unfortunately, the answer to this isn’t cut and dried.
The general rule of watering plants is that if the depth of a plant’s roots is hydrated, the plant has enough water. The other rule: If a plant acquires too much moisture, the roots will become waterlogged, prohibiting water absorption and essentially having the same effect on the plant as drought. If an area becomes flooded for a prolonged period, you may have the added problem of damaged soil structure.
What can you do about too much rain falling on your plants? Aside from diverting your gutter drainage or a general withholding of manual watering, not much. However, a few more creative options are available if you have a landscape area particularly prone to always being wet.
Gardeners have found methods to address long-term excess water in ways that work toward their success, not against it. They include elaborate drainage systems, gardens made for the rain, and plant specimens chosen explicitly for their absorption capabilities.
Looking at drainage, French drain systems entail underground basins of rock buried underneath a thick layer of soil, often with a drainage pipe also existing in the rock layer. With the basin of a French drain containing large pockets of air, water is allowed to percolate through the soil layer above it readily, keeping the plants above adequately watered and not drowning. These can be particularly useful if you have an area of yard that always floods and puddles, harming the plants growing there. The downside? Installation labor can be hefty, as can the cost of materials.
Instead, those looking to put their money elsewhere could consider investing in landscape plants that will equally accomplish the job of draining excess water. “Rain gardens” are planted explicitly to absorb excess puddling water during rainy times and withstand periods of drought during dry spells.
Typically planted in low-lying water collection areas, rain garden plants have two categories: low-lying and slope. The low-lying plants can include swamp milkweed, sedges, giant goldenrod, cardinal flower and New England aster. Slope plants can consist of drier specimens such as yarrow, purple coneflower, daylily, liatris and rudbeckia.
Do you not want a full garden but still want to siphon water away? Consider a tree known to grow well in wetlands. By their physiology, they adapt to absorbing mass amounts of water while it is available and then living off that water during dry periods. These include bald cypress, willow, red maple, river birch and swamp white oak.
Anthony Reardon is a horticulture agent with Kansas State University Research and Extension. Need help? Contact the Johnson County Extension gardening hotline at 913-715-7050 or email garden.help@jocogov.org.
