Soil is the foundation of every healthy garden, but not all soils are the same.
Alice Slusher
Some hold too much water, while others dry out quickly. Some are full of nutrients, but others need a lot of care to stay healthy.
Knowing what kind of soil you have is one of the first — and most important — steps to growing a successful garden.
Testing
You don’t have to send your soil off for testing to get a good idea of its type. One easy way is to do a simple feel test.
Grab a handful of soil that’s damp but not wet, and try to form it into a ball. If it crumbles easily and feels coarse or gritty, it’s probably sandy soil. If it holds together firmly and feels smooth or sticky, you’re likely dealing with clay.
If it’s somewhere in between — holding its shape but still breaking apart with a little pressure — you may have loam, a balanced mix of soil types. Loam is great because it holds just the right amount of water and drains well. It’s easy for roots to grow in and packed with nutrients and good stuff that plants need to stay healthy.
People are also reading…
For a more detailed look, try the jar test. Fill a clear jar halfway with soil, add water, shake it well, and let it sit for 24 hours. The soil will separate into layers: sand at the bottom, silt in the middle, and clay on top. The thickness of each layer gives a rough idea of your soil’s makeup.
Clay soil
If you find out you have clay soil, you’re dealing with something nutrient-rich but that doesn’t drain well and gets really hard. Clay particles are tiny and pack tightly, making it tough for roots to grow and breathe.
Water may sit on top or soak in too slowly, causing root rot or weak plants. Avoid working clay when it’s wet because it gets even harder as it dries, like concrete. Improving clay takes time, but adding compost, leaf mold, or aged manure regularly can help loosen it.
Don’t fall for the idea that sand will help—mixing sand with clay can make it worse, creating a hard, cement-like soil.
When planting in clay, dig wide, shallow holes to keep water from pooling.
Many plants do well in clay, like native species, ornamental grasses, daylilies, asters, and serviceberries. Deep-rooted veggies like carrots and beets can help break up heavy clay by making tunnels that let water and air through.
Aerating or “forking” the soil also helps — gently rocking a garden fork opens air channels and reduces compaction. Afterward, top with compost to improve soil over time. Raised beds or mounded planting can give roots a better environment above the clay.
Sandy soil
Sandy soil, found in river-bottom areas, has the opposite issue. It drains quickly and warms up early — great for spring planting — but it dries out fast and doesn’t hold nutrients well. Plants may become underfed or dry out quickly without consistent care.
To improve sandy soil, add generous amounts of organic matter such as compost, aged manure, or coconut coir to help retain water and nutrients. Mulching with straw, leaves, or wood chips protects the soil and keeps temperatures stable.
Since sandy soil doesn’t hold water well, it may require more frequent, deep watering. Drip irrigation works well. Fertilize gently but regularly, as nutrients leach out quickly.
Many vegetables grow well in sandy soil with the proper care — carrots, potatoes, tomatoes, peppers, and herbs are all good choices.
Other options
If you’re struggling with either extreme, alternatives like raised beds, containers, or lasagna gardening (layering compostable materials) allow you to bypass poor native soil and build healthier growing conditions over time.
And if your soil is somewhere in between, you may already have a good starting point. Even so, annual additions of compost help retain moisture, support soil life, and improve structure.
Whatever kind of soil you’re working with, understanding its texture and needs is the first step to gardening success. With the right practices and a bit of patience, you can turn even the most difficult soil into a thriving, productive garden.
Around the Yard is a monthly column written by Washington State University Master Gardeners of Cowlitz County and provides answers to local gardening questions. To ask a question, contact Cowlitz County's WSU Extension Director Gary Fredricks at garyf@wsu.edu or 360-577-3014 or the free Cowlitz County Master Gardner Plant and Insect Clinic at cowlitzmastergardener@gmail.com.
Alice Slusher has been a WSU Master Gardener for 12 years, serving as director of the Cowlitz County Extension Office's Plant and Insect Clinic and becoming familiar with the majority of problems that occur in the area's wet, cold, rainy winters and springs, as well as in its hot, dry summers.
