I have never planted root vegetables before so I don't know how to tell whether it is ripe or not without pulling the root out of the soil and seeing it.

I love beets and I love carrots also but if I ever grow them, I am going to have to know when they are ripe without pulling them out of the soil. One solution I can see to this is hydroponics where you grow plants in nutrient enriched water. There is just one problem with that. Roots, whether you are talking about the edible roots or the non-edible roots, need oxygen and the little bit of oxygen that is dissolved in water is not enough. However too much oxygen can kill the plant if it isn't doing cellular respiration fast enough.

So how would I know when a beet or a carrot or any other edible root is ripe without pulling the root out of the soil or risking lack of oxygen and oxygen poisoning with hydroponics?

  • 1
    You can grow carrots hydroponically and aeroponically. I've never heard of oxygen poisoning, and doubt it exists. The more oxygen roots have, the better they grow. Commented Feb 4, 2016 at 5:20
  • But the real problem is when too much oxygen gets to the leaves. The stomata are closed at night to keep water in and because of that oxygen can't get out. More oxygen does not mean faster cellular respiration. And you know what happens when too much oxygen gets to the leaves? Photorespiration. These oxygenated products are no good for the plant and they are too big to leave through the stomata. This means that they start to build up in the plant. I don't know of anything in the plant that metabolizes these oxygenated waste products.
    – Caters
    Commented Feb 4, 2016 at 18:46
  • Photosynthesis is the process whereby oxygen is released by the plant. It needs light. At night there is no light so oxygen is not being generated inside the leaves. Commented Feb 4, 2016 at 19:15
  • But still oxygen is transported to the leaves for cellular respiration at night. I didn't say it was generated inside the leaves at night. And even during photosynthesis there is still a limit as to how much oxygen can get out of the plant, especially during the summer. This increases the chances of or causes photorespiration which gives the plant these oxygenated waste products it can't use.
    – Caters
    Commented Feb 4, 2016 at 19:17
  • Which product of cellular respiration concerns you? ATP, co2, or water? Commented Feb 4, 2016 at 19:44

4 Answers 4


Well, it is so easy, it will probably surprise you:

Beets and carrots grow partly above the soil, especially when they mature.

Especially beets - you may assume that about half of the thick, fleshy part remains exposed. See this picture and note how only the lower part shows traces of soil:

enter image description here (Source)

Similar for carrots, but you may have to wipe away a tiny bit of soil to get a better idea of the current thickness:

enter image description here

The dates on the seed packets will give you a good idea about when you should expect them to be fully ripe, but you might choose to harvest sooner ("baby beets") or later, if you feel they "need a bit more time". Roots don't spoil like fruit does.

Practical side notes:

If you planted the seeds a tad too close (like in the carrot picture above), you can harvest baby carrots etc. to give the remaining plants adequate room. Likewise, you can stretch your harvest by pulling the largest specimens for your current kitchen needs and letting the smaller ones grow a bit longer.

This does apply only to some extent to radishes, they can get woody or hollow if too old. Here you have only a few days of leeway between "fully grown" and "too late".

  • In my area, you gotta keep them hilled up to blanch them or they get bitter and green
    – J. Musser
    Commented Feb 3, 2016 at 23:42
  • @J.Musser - carrots or beets?
    – Stephie
    Commented Feb 4, 2016 at 6:07
  • Both - but more importantly in carrots because beets get peeled. If it's more than skin deep in beets (which happens) they taste awful. Carrots have a thinner skin. The turn green almost to the center in sun
    – J. Musser
    Commented Feb 4, 2016 at 17:21
  • @J.Musser interesting! Learned sth. new, thanks!
    – Stephie
    Commented Feb 4, 2016 at 17:22

Most root foods don't actually "ripen" and can be harvested at any time. If you're looking to maximize the size of the root, some things like carrots and beets will start to show the crown of the root above ground giving you some indication of their size. Other roots like potatoes is pretty much going to be a trust with timing depending on what size you are going for but no matter the size, they are all edible.

  • I think examining the crow of the root is the most effective way to go. That has been my experience as well
    – JStorage
    Commented Feb 23, 2016 at 21:35

For carrots it depends on the type. The seed packet will give the best idea on how many days it will take, but here are some general guidelines:

Baby carrots: 50-60 days

Mature carrots: around 75 days

In most cases, you can look for the tops of the carrot to be about 1/2 - 3/4 of an inch in diameter.

For beets, again the seed packet will give you a good estimate on the length of time to let them grow.

They can get up to about 4in in diameter, you can pull them when they are the size you'd like after about 45 days (once again take a little soil off the top and you can get a feel for the size of the beets).


Unless you are a farmer producing for some bulk processing use, odds are high that you'll harvest over a period of time anyway. As such, yanking a sample is not detrimental to the overall harvest - it's part of it. If you are a farmer, you'd be sampling anyway.

Both beets and carrots normally need thinning (reduction of plants in the row/bed to allow adequate space for the remaining plants to attain full growth) anyway, and the thinnings are all edible, as well as giving you some idea of progress in growth. And, of course, there's the number of days from when planted and/or emergence - harvest by calendar.

If you are aiming for a bulk harvest to store for personal use, you'll need to plan the planting time so it's ready to harvest (or mulch for later digging, if storing in the ground) when frost comes, and it won't much matter what size it actually is, as that's all you'll be getting that year - which is once again harvesting by calendar (by planning the planting date.)

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