how to grow carrots, with dr. john navazio

WHEN THE MOST COMMON CHALLENGE readers confessed in a recent story on vegetable gardening was “I can’t grow carrots,” I knew who to call: John Navazio, Ph.D. to the rescue. John, who at time time served in a joint role as Senior Scientist for the Organic Seed Alliance and the Washington State University Extension specialist for organic seed for his home state, has grown—and bred—more than a few carrots in his time.

John, whose dramatic and delicious purple ‘Dragon’ carrot is bright orange inside, was reassuring as ever. First, don’t feel bad, he said. “Carrots are one of the harder vegetables to grow,” confirms John (with flowering carrots in an OSA photo, above), and for a few reasons:

They’re such small plants when they first sprout (the seed isn’t too big, either; I like to use pelleted, shown below, and there are now pelleted ones that meet organic certification requirements).

To get really good quality you need “unchecked growth”—no obstacles either literal (like rocky or otherwise tough soil) or meteorological (extremes of heat, cold or especially dryness). “Succulence and flavor will suffer if the growth is checked,” John explains–and so can their shape.

Would that we all were surrounded by a true loam (meaning an ideal soil with equal parts sand, silt and clay)—but since we’re generally not, the answer, John says: compost.

“Adding lots of organic matter—not bagged products, but high-quality local compost in bulk—will help you grow good carrots, and it will also help solve problems many gardeners have growing broccoli, cabbage and Brussels sprouts to good size,” says John, who is now manager of plant breeding at Johnny’s Selected Seeds in Maine.

john’s carrot how-to:

  1. Plant your root crops, including carrots, in the least-rocky soil you have.
  2. The soil should have a good “tilth”—with plenty of organic matter in the form of compost incorporated.
  3. Plant early, but not too early. A 70-80F degree soil temperature is ideal, but if you are patient, and don’t mind slower germination, plant in spring once soil temps are consistently above 60F, or as the old-timers would say “once the weather has settled.” (Many gardeners stagger sowings to have fresh-eating carrots over a longer season, timing their “storage” types to harvest late.)
  4. Don’t overwork the soil; a fine powder (which can result from mechanical tilling) can crust over—and crusting=checked growth=bad news. Just work the soil enough to create a welcoming seedbed.
  5. Plant the seed ½ inch deep and don’t sow too thickly! Better to space correctly than to thin. “I’m a great believer in putting down the exact amount you need—not too little, and not three to five times too much!” John advises.
  6. Assuming you are using fresh seed or a leftover packet that has been properly stored, germination would be about 80 percent, so:
  7. “Take your time, and carefully place 16-20 seeds per foot in the row,” John says. If you have good seed, you’ll be ‘planting to stand,’ as farmers say—plant right, and you eliminate thinning time.” The successful plants will end up about an inch apart.
  8. Alternatively: Plant staggered in 2½- to 3-inch-wide “bands.”
  9. Gently tamp down the seedbed once sown; don’t step on it, be gentle.
  10. Be prepared to wait 7-10 days for germination.
  11. Keep the seedbed evenly moist till the seeds emerge. Especially in clayey soils, crusting must be prevented or else!
  12. Make light, frequent sprinklings to a depth of 2-3 inches. If the seed’s tiny radicle—the embryo’s primary root—meets resistance? Death, says John.
  13. A trick to “mulch” the seedbed: “Sprinkle a very light layer of grass clippings on top of the row to keep things moist,” he says.
  14. Or the tip John likes best: Sow radish or even better turnip seed among the carrots. Both germinate extra-fast, and help break through any possible crust.—and also mark the row, since they sprout before the carrots.  “Pick the tiny plants and eat the baby leaves in salad,” he advises.
  15. If you planted too thickly and must thin (like the seedling below), do so in the first couple of weeks after emergence.
  16. Weeding is essential—early and often; ferny-textured carrot foliage isn’t much competition for weeds. Hand weed; don’t let any competition get established.
  17. Remember our mantra throughout the growth cycle: unchecked growth. The taproot of the carrot is below the carrot itself–meaning what John calls the “buggy whip” (like the one in the photo above), which can be 14-18 inches long, needs water. Soak deeply as the plants grow.

when are they ready to harvest?

DON’T JUDGE a carrot by its seed packet’s days-to-harvest number. Catalog and labels may say 65-70 days for many varieties, but “that is not my experience,” says John. “They can take 95-100ish even.” How to tell? Pull a few to see if you’ve got “tip fill” yet–at least some degree of blunting at the end, and also to taste for full development of flavor. You can eat them sooner, of course, but why waste a mouthful?

which carrots to grow?

FOR THOSE who have had trouble growing carrots, John recommends a couple of sturdy but delicious varieties to get you started:

  • ‘Paris Market‘ types (the early, fat, rounded little guys), or ‘Oxheart’ or ‘Atlas’ don’t develop deep roots, so these should boost your confidence.
  • ‘Red Core Chantenay,’ with big shoulders, need somewhat deeper soil, but are strong growers. “They can get as big as a coffee mug around and 10 inches long,” John says. “They’re great for cooking–those are the diced carrots in every can of soup.” While delicious, Nantes types (cylindrical like a cigar, not tapered) prefer better soils. They have wonderful fresh-eating flavor, so get out the compost and go for it. John recommends ‘Scarlet Nantes’ in particular.

“I’ve put a lot of thought into how to build a better carrot,” says John, who now has his sights set on breeding carrots with strong, vigorous tops that will outcompete weeds more successfully.  “That will be a really key breakthrough for organic agriculture.”

about the organic seed alliance

THE ORGANIC SEED ALLIANCE, a nonprofit started 10 years ago, “advances the ethical development and stewardship of the genetic resources of agricultural seed” through education, advisory services, and research programs with organic farmers and other seed professionals. In his role there, John Navazio strives to foster regional seed independence through participatory breeding projects with farmers, aiming for what he calls “farmer-centric seed systems” that select for germplasm well-adapted to each particular area.

The OSA blog is a great place to keep up to date on developments in the politics, and science, affecting our seed supply; the “advocacy” section of the OSA site suggests tactics for expressing feedback to government agencies and others about developments (such as transgenic/GMO sugar beets) that threaten our organic seed resources.

You may recall I shouted them out last year in a story about why I purchase organic seed when available.

John’s book, “The Organic Seed Grower: A Farmer’s Guide to Vegetable Seed Production,” was published by Chelsea Green in August 2012.

  1. Great tips, on a topic I don’t see much info about. I especially appreciate the suggestion of Parisian Market as a confidence-boosting variety. I do not have rocky soil (i live on a sandy bluff and build raised beds), but perhaps I need to be composting more, or watering more. My carrots (usually Scarlet Nantes) just never reach good size. Thanks!

  2. I’ve actually had good success with Scarlet Nantes – my toddler would pull one out of the garden and ask me to wash it immediately! I’m trying “Little Finger” this year so I can grow them in a more shallow bed.

  3. tropaeolum says:

    I grew carrots for the first time last year. Success! Unless you don’t like your carrots munched on by weevils. I just cut off that bit and fed it to the dog.

    I do have a question, though. I planted carrots at my sister’s school in Seattle. They got tops but no bottoms. Any idea what went wrong? I wondered if the soil was too acidic and/or if they were missing a key nutrient. It’s hard to believe they didn’t get enough water in Seattle, but that’s possible.

  4. Kristi says:

    Carrots aren’t very glamorous, glad to see someone giving them their due. Last year was my first successful attempt at carrots. They looked lovely, but had a metallic after taste. Not sure if they were in the ground too long, or it was just the variety. I’ve bookmarked this article to reference later. Thanks.

  5. I think this is the best article on growing carrots I’ve read.

    I had trouble with them the first couple of years I tried, too. Eventually, as you develop patience as a gardener and the ability to do a good job seeding them and caring for them, they come up beautifully. I grow 4 different colors now and it’s a real treat.

  6. Trixie says:

    I’m a big believer in planting only the necessary amount of seed and not having to thin later on. So glad I am not the only one who does this!

    I planted Amarillo carrots last year and they were delicious. Will definitely plant a bigger crop this year.

  7. Lorie says:

    When I was 4, and the product of the Victory Garden era, I was taken to the nuns’ space where they were growing carrots outside the front door of the convent. I was to tell them when the carrots were “ready to pull”. I extracted a horribly thin specimen and tried desparately to put it back in the earth…have never forgotten the humiliation.

  8. Lanette says:

    Here in Western Washington State, I have the best luck with Nantes — sometimes have spotty germination (but I tend to use my older seeds if they show ANY signs of life!). I have the best carrots in the fall and winter — still have a lot of good ones in the garden right now, and I didn’t mulch. Critters have been working on the top inch but there’s plenty left for us.

  9. Liz says:

    Wow! Great to meet you, Dr. Navazio! Purple Dragon is my favorite carrot. I love the colored carrots. I have stony soil, so I had some soil trucked in for raised beds last year. It turned out a bit clay-ey, so I added lots of compost, and my carrots grew quite well. It is just hard waiting and waiting for them to sprout! I usually don’t have the patience to place the seeds carefully; I usually just bradcast them over an area, but I will try careful placement this year.
    Thanks for the article!

  10. alice schrade says:

    so i am persuaded to try carrots again. I am gardening in a group area ( retirement center apartments ) in a newly installed raised bed..just today i put it up. i can add good soil and plant carrot seed . It was such a lovely day. and the soil smelled really good, a good sign it’s healthy. Last year was my first here and I added LLama ‘beans” to the soil. Tomatoes, beans, beets, chard, lettuce, maybe cukes, and of course zucchini ,along with the carrots and i’m good to go. I have to brag, my soil looks better than anyone else’s . It was the llama poop and I wouldn’t let them rototill.. Will report later on on how the carrots did.
    Thanks so much for the advice.

    1. margaret says:

      Glad to help, Lissa. I know I am going to sow slower and not overdo it with seed anymore…skip the thinning by planting “to stand” this year.

  11. Clare says:

    Great tips on growing carrots!
    I’ve been creating my own carrot seed tapes to make it easier to “plant to stand”. I cut one inch wide strips of paper towels and write the name of the type of carrot seed onto the strip. I put small drops of standard, white (Elmer’s) glue onto the strip about two inches apart, then place about two carrot seeds per drop. Let the glue dry and then roll up the strips to store until it’s time to plant them (I’ve even used strips a year later). The strips are a snap to plant and I’ve found them just as effective as pelleted seed in planting “to stand”. Plus, I can make the strips while sitting at the kitchen table while waiting for spring and watching it snow, yet again….

  12. Amy says:

    Just want to chime in, since I have finally been able to grow carrots successfully, here in Southern California. My key to success has been to use a single layer of burlap over the seedbed, until the carrots are well up (poking their greenery through the burlap). I then gently lift the burlap, and fasten it to little bamboo hoops (about 8″ high), so it hangs over the seedbed and provides some protection from birds. Voila, carrots! These are raised beds with compost added. The carrot seeds are planted in 8″ wide swaths, broadcast rather carelessly :) Using this method, we grow carrots year-round.

  13. igardendaily says:

    So much good information here! I’ve had success growing several varieties in raised beds but always have the problem of thinning. I think I’ll take more time and try “planting to stand.” I have never really known when they are “done” (ripe) but now have something to go by. Thanks again!

  14. Sarah says:

    Our soil is horribly rocky, but the Nantes always perform better than anything else. The one thing I don’t like about them is how easily their tops snap off.

  15. mike engle says:

    We have never grown good carrots up here in Troy, NY, but with these tips, lets see if I can grow some Cosmic Carrots.

  16. Leonard Vassallo says:

    I grow great carrots in eastern Canada but have a problem with Carrot rust fly which emerge in storage. Any simple ways of dealing with it?

    1. margaret says:

      Hi, Leonard. This Washington State University fact sheet recommends adding lots of organic matter to your soil, of course, and also prompt harvest (not storing in the ground) and use of well-sealed row covers (and not planting int he same soil that was infested the previous year), among other tactics to reduce the possibility. So a lot like what I wrote about for flea beetles in this other recent post. Planting a later carrot crop (not early spring but maybe waiting till June) can mean your carrots miss overlapping with the insects’ life cycle, too.

    1. margaret says:

      Hi, Paul. The first few weedings in the home garden are usually done by hand with delicate seedlings like this. I use a little fine-textured mulch alongside the row after the carrots get up and growing, but I don’t heap deep mulch on them.

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