10 Soil Indicators for Your Vegetable Garden

Enlarge Image Image Gallery Keep an eye on your soil and look for indicators to catch problems early on. iStockphoto.com/Polarica

The fun of gardening can quickly turn to frustration if a row of squash fails or your tomato plants produce no fruit. At some point, even the best gardeners must put on their detective hats and find out what went wrong.  While deer prints may be a dead giveaway, most gardening problems stem from less-obvious problems with soil health. Luckily, poor soil leaves clues that are easy to spot with practice. Gardening experts have compiled 10 warning signs of trouble in the garden. Knowing these, you can troubleshoot your own garden.

Do the numbers

Doing a soil test is as important to gardening as getting a survey done before you begin building a house. A good soil test will tell you the pH balance of your soil, as well as its levels of key nutrients. Troubleshooting soil health is easiest to do before anything is planted, says John Jemison, water quality and soil specialist at the University of Maine Cooperative Extension in Orono.

“Gardeners really need to do a soil test as a first step because then they have a plan,” he says. 

Not all soil tests are created equal, however. Susan Littlefield, horticulture editor with the National Gardening Association in South Burlington, Vermont, has found wide variables between soil tests. While there are affordable DIY soil tests on the market, Littlefield recommends getting your soil tested with a professional tester or through a cooperative extension office before taking action. For more, see “Know Your Soil” on Page 64.

Standing water

A garden should drain. If water pools in your garden long after a hard rain, that’s a problem. 

Nowhere is this problem more apparent than in the moist Pacific Northwest. Falaah Jones, an environmental educator with Seattle Tilth, gets many calls from gardeners with soggy crops through the organization’s helpline (206-633-0224). Eager gardeners plant too early in the wet spring in poorly drained ground, only to watch their seedlings die.

“People want to put in plants, and they jump the gun,” she says.

Roots need oxygen, and plants can drown just like humans. Ground that is too wet also can drain away valuable nitrogen, create mold and fungus problems, and block a plant’s absorption of necessary nutrients. Ground that is too spongy will need material to create air pockets to aerate the soil, such as hummus, as well as good draining material like sand.