Ask Gardenerd: When do I harvest my root crops?

A question came into Ask Gardenerd this week that I’ve been hearing for the past month or so.  Seems like a good time to address it:

“When do you know when to pull out things that grow underground like
radishes, green onions, even carrots?  I’m either too early or too late. – Rochelle”

Well Rochelle, the answer is in your hands.  More specifically, it’s your index finger.  When growing root crops, the foliage will put on a pretty show above ground, but the real magic is happening underground.  In order to tell how your carrots and other subterranean dwellers are progressing, use your index finger to determine the diameter of the root. Root crops are only rooted at the very bottom so it doesn’t harm the harvest to investigate this way.

Freshly harvested parsnips


The Trick: Brush away soil around the circumference of the carrot until you can feel or see the outside edge.  You then can see the diameter of the carrot and if it is the size you want it to be, then pick it.  Generally speaking, most carrots are ready to pick when they are 1 to 1 1/2 inches in diameter.

Now it’s not uncommon to pull up a carrot that is 2 inches in diameter only to discover that it’s also 2 inches long, but for the most part, you’ll find that the diameter indicates readiness.  This trick works with carrots, parsnips, beets, radishes and turnips.

As for green onions, if you are growing them as scallions (meaning you’re not letting them form a bulb) you can pick green onions at any point once the greens are the thickness of a pencil.  I’ve harvested them much later than that (they looked almost like leeks) and they were still delicious.  However, if a green onion sends up a flower stalk, the onion will have a tough center and that part will need to be discarded.

It’s as simple as that.  Thanks for writing in, Rochelle, and enjoy those carrots.

This Post Has 4 Comments

  1. Christy Wilhelmi

    Lettuces love cooler weather, and carrots can be persnickity.  If you aren’t sure about the viability of your seeds (if your seeds are a couple years old) you may want to try a germination test first, or get new seeds.  If they are new seeds, try again in fall.  Many root crops do well in cooler weather. 

  2. joanne t

    Thank you. It was very helpful information

  3. Ivan

    As a newbe, I’m not sure how much to water. I have six different fruit trees mostly dwarf and planted tomatoes, squash, melons and several different herbs. The San Juaquin Valley gets really hot in the summer and some of what I planted has dried up.

  4. al

    only a few carrots up out of 2 rows, dutch set onions fine, radishes slow, lettuce too. Planted about 1 mo later than usual. High 20’s, low 30’s Celsius in N Ontario, Canada. I’m guessing carrots & lettuce need cooler weather at start to establish selves. Perhaps radish also. Am watering most evngs.with watering can. Your advice?

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