Growing Veggies? Check Soil’s Drainage and Composition

Clay Soil

Clay Soil

This type of soil feels smooth and sticky, and can be rolled into a ball when wet. Clay is also porous and holds nutrients and water well, although plants cannot extract all of the moisture from clay, because an electrical charge on each of the particles holds it too tightly—rather like iron filings clinging to a magnet.

So you’ve decided which veggies you want to grow this year, figured out where you’ll plant your vegetables, and designed the garden plot. All that’s left is waiting for the weather to get warm enough for planting, right?

Not quite! Whether your veggie garden will be a bounty or a bust depends in large part on the quality of its soil, and unhealthy soil can lead to unhealthy – or even unsafe – vegetables. If you haven’t already, now is the time to get to know your soil so that you have time to amend any issues before those plants go in the ground.


All soil is made up of sand, silt, and clay in different proportions. If your soil is very sandy, it will drain well but won’t be able to supply your growing plants with essential nutrients. A clay soil will be nutrient-rich, but will have trouble draining. An ideal soil is loamy – about equal parts clay, silt and sand.

To test your soil’s composition, pick up a handful of moist (not wet) soil and squeeze. If it holds its shape but crumbles when you poke it, you’ve got a nicely balanced soil. If it falls apart as soon as you open your hand, it’s sandy. And if it forms into a firm ball that won’t crumble even when poked, it’s heavy on clay.


Most plants don’t like wet roots, so you’ll want to make sure your soil drains quickly enough using the percolation test. Wait until your ground is well-thawed, and then test a few different areas by digging holes about 12 inches wide by 12 inches deep and filling them with water. After the water drains out, refill it right away and measure the depth with a ruler. After 30 minutes, measure again to see how much water has drained out. Since the ideal drainage rate is 1-2 inches per hour, you’ll be looking for about ½ – 1 inch of drainage in a half hour.

Composition and drainage are two important factors in a veggie-friendly soil, but they aren’t the whole picture. Next, you’ll want to test pH and nutrient levels, and maybe even check for common toxins like lead.

And no worries: If your soil is a real mess, raised beds are always an option. 

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