Gardening in wet soil is a hard thing to do up here in the PNW! If the soil can’t drain properly, it keeps the plants from getting oxygen. Also, roots can rot and give your plants other diseases. While this seems counterintuitive to how plants grow since they need water… it’s just not possible for plants to grow in soil that is wet for prolonged periods of time.

The first thing you want to check is if your garden sits in a low area that lacks drainage. If it does, this typically is what is causing your wet soil.

Also, check the locality of your septic tank and its drain field. I’m sure in your files you have a septic system design of where everything is. It’s ideal to not garden around these areas unless you’re using the area for more wetland friendly plants.

Here are some steps on how to fix it:

  1. On both sides of your garden, dig a trench that gradually gets deeper towards the back. Then fill it with medium-sized rocks. This will allow the garden to drain the water to these trenches.
  2. If the trenches aren’t an option, try adding extra soil to the middle of the garden. This acts as a “mountain” that allows water to cascade to the outskirts of your garden. Obviously this isn’t as effective as the trenches.
  3. Add a layer of compost or manure rich soil where the soil is wettest. This organic matter can increase the draining properties of your soil.
  4. Choose plants that flourish in the wet weather! If you’ve just moved to the PNW, gardening can be a learning experience. But the obvious and best course of action is to set yourself up for success and try and stick with these types of plants. Think ferns and large bladed grasses.

If you need to check the drainage rate of your soil, dig a hole about 1 foot deep. Fill it with water. Measure the depth of the water after 1 hour (or 15 min, then you can multiply by 4 to get a rough estimate). If the hole has only drained 1 inch, this is a poor result. The ideal drain rate is between 1 and 6 inches per hour. With the optimal at 3 to 4 inches.

Tools You Will Need

  • Tiller
  • Shovel
  • Rake
  • Rocks
  • Compost or manure

I would like to thank my friends at Concrete Polishing Tacoma as well as my other friends at Concrete Finishing Bellevue. Both are great supporters for my gardening blog and because of them, I’ll continue to write!