By Paul James
I love rain, especially when it follows a long day of planting or starts right after I’ve finished mowing the lawn. But too much of a good thing is rarely a good thing, and too much rain can wreak havoc in the garden, often in some rather unsuspected ways.
Perhaps the biggest problem is that too much rain can actually drown plants, because all that water in the soil fills spaces that would otherwise contain oxygen. When that happens, plants aren’t able to respire (or breathe, if you will) and therefore suffocate. Carbon dioxide and ethylene gases can also accumulate, both of which can be toxic to plants.
Symptoms of waterlogged soils include plant leaves turning yellow or brown or wilting suddenly. Die back of new shoots is also fairly common. And unfortunately, short of waiting for the soil to dry out, there’s not a lot you can do to reverse the situation. Pulling back the mulch from around plants (or the entire garden) will facilitate drying somewhat, as will stabbing a garden fork in the soil, which also allows oxygen to reach into the soil.
Too much rain can also leach essential nutrients out of the soil, especially nitrogen, so once the soil dries out a bit, consider applying a fertilizer such as Espoma Plant-Tone, Milorganite, or Osmocote, or simply topdress plants with compost.
Dirt and mud that splash onto leaves and stems may – and often do -- harbor fungal spores, which is why it’s a good (if not counterintuitive) idea to wash the entire plant with a gentle mist. And on plants that are susceptible to fungal diseases – tomatoes in particular – you might want to apply a fungicide such as all-natural Serenade as a preventive measure.
But be careful where you walk! Your weight – regardless what it is – can cause severe compaction in wet soils, and compaction is the enemy of plants. If you have to work in the garden, place a board on the ground first and walk on it to minimize compaction. Walking in wet soil can also hasten the spread of fungal diseases, especially on beans.
Pollination can also be affected by heavy rains, in part because pollinators have a tough time flying in the rain, but also because heavy, wet pollen simply isn’t as effective at doing its thing. There’s not much you can do to remedy the problem short of waiting for the weather to change.
And finally, we’ve all been frustrated during those times when frequent rains make it impossible to get out and mow the lawn, and by the time it’s dry enough to mow the grass is overgrown. About the only way around the problem is to double cut: raise the deck to its highest notch, mow, then drop the deck height to your preferred level and mow again.
So there you have what you need to know about dealing with too much rain in the garden. Now I’m going to write a piece for the coming months on how to deal with drought.