Expert Gardening Advice for Growing Root Vegetables

Garden guru Doug Oster answers a reader-submitted question about root vegetables that don’t seem to grow properly.

Radishes

Radishes are a good crop to test your soil’s health because they only need about 30 days to reach fruition.

Photo courtesy of www.RareSeeds.com

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Root vegetables never seem to grow properly for me. I’ve tried beets, parsnips, and carrots, but only the carrots grew. What could I be doing wrong?

When root crops don’t properly form, it might indicate that your soil pH is out of balance. That’s especially true of beets. Plants can’t properly uptake nutrients when the soil pH isn’t optimum. A pH of 6.5 is just right for most plants. A soil test from your local county extension is an inexpensive way to find out if your garden’s soil has become too alkaline or acidic with time. Compost amendments will help level out your soil’s pH and will also create a rich growing environment for just about any crop.

After you figure out pH issues, try planting root vegetables again, with attention to proper spacing and thinning. These details are crucial for root crops because they need enough room to reach full size. (Most seed packets include thinning instructions on the back of the package.)

I’ve discovered a handy trick for using thinned radish seedlings. Because I don’t need any more half-packets of radish seed in the basement, I tend to plant an entire package on a bed of soil spread thick with compost. As soon as the radishes sprout, I thin them according to the package’s directions and use the thinnings in a salad. These microgreens are nutritious, tender, and sweet. I use the entire young plant, top and bottom, to give salads a wonderfully fresh flavor. Radishes only need about 30 days to reach fruition, and they love cool weather, so start your seed early and try for a few succession plantings.

If any of your radishes don’t form edible roots, just let them keep growing. Their flowers will attract beneficial insects, and they’ll eventually produce lots of edible seed pods. There’s nothing better than serving a “leap of faith” salad sprinkled with radish seed pods. I love to watch guests nibble on them, wondering what they are.

Beets are also a great winter crop. Start them 10 to 12 weeks before your average first fall frost date so you can harvest some greens through the cold weather. If there’s enough time for the root to form, you can mulch those beets with straw and harvest during a thaw. It’s fun to tell gardening friends you’re eating from the garden in December.

For more advice from Doug Oster, see:

Is Vermicomposting Tomato Plants a Good Idea?
Attracting Beneficial Insects with Pollinator Plants


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All of this issue’s questions were submitted via Facebook. For a chance to see your gardening question answered in print, email it to Letters@HeirloomGardener.com, post it on our Facebook page, or share it on Instagram with the hashtag #HeirloomGardener.


Doug Oster is the home and garden editor at the Pittsburgh Tribune-Review and is co-host of The Organic Gardeners on KDKA radio. Doug’s book Tomatoes Garlic Basil contains even more useful information.