Gardening Tip - Identifying Clay Soil

San Diego is a gardener’s dream.  Our moderate temperatures mean that we can grow a dazzling array of plants all year.  The downside to San Diego is that in many parts of the county we have poor native soil for growing all those beauties we see in Sunset magazine.  There are several types of soil in the county.  Today’s post will cover heavy clay soil. 

      How do you know if you have this type of soil?  First dig a small shallow hole about 12 inches wide by 6 inches deep.  Is the soil hard to dig, even though you are not hitting any rocks?  Next fill it with water and let the water drain out of the hole into the soil.  Does the water drain quickly while you are standing there or does it just sit there like a really gross bird bath?  A really gross bird bath means you have clay soil. Still not sure?  Let the water drain completely out and then refill the hole with more water.  If the second batch of water drains slower than 1 inch per hour, you have clay soil.

      Another test is to scope out a handful of soil from that wet hole.  Does the soil feel like playdoh in your hand when you squeeze it or does it slip through your fingers in loose pieces?  Wet clay soil will feel like wet clay (thus the name).   Because of its dense structure, clay soil really holds onto the water which can drown a lot of great plants that need good drainage to survive.  So what can you do to fix this?  Tune in tomorrow when I will tell you how.