Drainage Advice from the PNW's most beloved expert, Ciscoe Morris

Soil and drainage

In the new book written by Master gardener Ciscoe Morris, he gives great tips and tidbits from getting rid of weeds in an environmentally safe way to mole control. Our favorite section was his guide to testing the drainage in your soil.

Ciscoe writes, “When it comes to gardening, nothing is more important than the soil,”  “and one of the keys to knowing the quality of soil is how well it drains.” We couldn't agree more! We always ask that customers test their soil before coming in to buy your product with us.


Ciscoe suggests a simple and effective way to test your soil drainage in your yard. First dig a one-foot-square hole one foot deep, or multiple holes for a bigger project. Then, fill the hole with water right to the top. Leave it for 1 hour then measure how much water drains.


  • Water drains 1-3" in the hour:
    • You have great draining soil.
    • Ciscoe states that "you'll be able to grow practically any kind of garden plant with average drainage needs" He then suggests to till in compost to improve soil structure, add nutrients and micro-organisms".
    • Add 2-3" of any of our composts + till in 6" deep.
  • Water drains more than 4 inches in an hour:
    • Your soil is too sandy.
    • Add 3" of compost + till in 6" deep: 
    • Mulch yearly to reduce the need to water so often. 
      • Adding in a healthy dose of compost is the quickest way to give your soil more organic content, which will help improve the moisture and nutrient capacity of your sandy soil into proper garden soil. The more organic content you incorporate with your soil, the higher its water retention capacity will be. Combining sandy soil with organic matter creates a serviceable habitat for microbial life, creating a nutrient-rich base for your garden beds.
    • Water drains less than one inch in an hour:
      • Your soil drainage is poor.
      • If this is the case, you are probably dealing with clay or hardpan, which is VERY common for Ballard or Magnolia in the Seattle area.  NW expert Ciscoe says, "adding compost won’t solve your problem." He says, "there are 2 ways to deal with poor drainage, you can choose plants that thrive in poorly drained soil (by far the cheapest method), or you can bring in topsoil to create berms or raised beds."