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paulns

Root crop puzzle

18 years ago

We grow very nice carrots and potatoes but are lucky to get beets more than an inch in diameter, radishes often don't bulb, and turnips the last time we tried them were nothing but greens. We have sandy soil. The last soil test showed sufficient potassium and phosphorus levels. I would give up growing beets and turnips but the local summer resort chef wants them. Baby turnips are a gourmet treat apparently.

Does the answer to this seeming puzzle jump out at anybody here?

Comments (28)

  • 18 years ago

    Just amend your soil. ....just start adding minimum amounts. when my radishes, turnips etc are about two inches high, I start thinning them...on my hands and knees pulling those little buggars out one at a time until thinned and then I ad dirt up around the ones I left...Works like a charm...

  • 18 years ago

    This is something I've had to deal with. I'm not sure I've got it solved but I'm hopeful.

    The most common cause of failure of root crops to bulb up is overcrowding. Thin them early as possible to their final spacing.

    Soil here is sandy too. It drains quickly and requires irrigation when the weather doesn't provide enough, which is often. I think the droughtiness of our soil is sometimes a cause for little or no bulbing up of root crops. When I was a kid, growing radishes and beets where the soil had a lot of clay, there was never a failure to bulb up. We never gave it a thought.

    My best radish crops were grown under floating row cover. The main purpose was to keep out the cabbage maggot flies. Perhaps the row cover slowed the loss of moisture as well by partial shading and slowing of air movement.

    There are other possible causes, such as nutrient deficiencies, maybe magnesium or boron. Nutrients are readily leached out of sand. But that is the last thing to suspect. Thinning and watering are the first things.

    Quotes from an article about beets:

    "Thinning. The most common problem is not thinning the planting. Proper spacing is essential for a quality crop. Thinning is especially important for beets since each beet "seed" actually contains several seeds. Thinning should
    be done when seedlings reach a height of 3 to 4 inches. Leave the strongplants and remove the smaller, weaker plants."

    "Beets also respond to boron when grown on sandy soils, light-colored silt and clay loams, and alkaline dark-colored soils, such as in northwest Iowa. It may be omitted from acid, dark-colored soils. Based on a boron soil test, include boron at 2 1/2 to 5 lb. per acre applied over the row at planting. Do not contact with the seed. Boron is toxic to many vegetables, particularly beans, peas, cucurbits and corn. Thus, rotational plans may have to be adjusted."

    Jim

    Here is a link that might be useful: Beet Article

  • 18 years ago

    I would make sure you don't plant too many, too close. Usually problems with root crops like you describe are caused by crowding the plants.

    Here is a link that might be useful: Win $50.00 Of Free Seeds!

  • 18 years ago

    Most root crops resent drying out and too crowded conditions. If stressed, beet and turnips tend to just throw tap roots and foliage and around here, stop growing until throwing up flowering stems. My beets and baby turnips do best in light soils well amended with composted materials, something like a 1-2-1 NKP ratio on ferts. I messed up my last beet seeding because I failed to thin soon enough. An my guys used the wrong fertilizer for the turnip bed resulting in massive plants with monster turnips. Great turnip greens, though!

  • 18 years ago

    Plant all root crops in the right phase of the moon (third quarter - "dark of the moon") and under the best astrological signs and you will get good roots crops.
    If planted in the wrong phase, you will get nice tops but little or no roots.

    ~sweetannie4u

  • 18 years ago

    Looks like there's a near consensus about thinning - I do thin when they're pretty small but not soon enough from the sounds of it. A combination of that and the soil not holding water, maybe? Pesky little plants. And I'd promised the chef some beautiful chioggia beets. Our radishes were amazing the year we planted them in a new garden with loamier soil, which had me wondering if the difference was in heaviness of the soil.

    sweetannie, when I'm retired I'll try planting by moon phases; for now the days are just too short to figure that one out as well. It's an attractive idea.

  • 18 years ago

    Paul,

    Yep, there seems to be a concensus. I've scoured the Internet and that's all I can find.

    Maybe by mid-summer you and I will have this solved. I plan to grow lots of radishes, and maybe some beets. If attention to thinning and watering gives us good crops, we will be happy.

    BTW, my parsnips were puny last year too. Maybe for the same reasons. But a few gardening friends grew carrots thickly with no trouble. Hmm... There is lots to learn.

    Jim

  • 18 years ago

    I don't think carrots are as particular as radishes...and beets.

  • 18 years ago

    You don't have to figure out the moon phases by yourself, just go to farmersalmanac.com and click on the home and garden tab. I'm trying it this year for the first time to see if it makes any difference in my yields. But I must admit, sometimes it's rather irritating when you have a day of good weather and seeds to plant, but the moon calendar threatens you that they will rot in the ground!

  • 18 years ago

    I had never grown beets before and planted some starts in the fall for a spring crop.
    I just went out to pick lettuce for dinner, thought I might throw in some beet tops and accidentally pulled up a whole plant. It had the beet color, but was just a small baby carrot size. I'm sure I over crowded them.
    Is it too late in zone 8ish to thin them? It seems like most beet people are harvesting them about now. Or should I just try again next fall? Nancy

  • 18 years ago

    "I don't think carrots are as particular as radishes...and beets."

    That figures. Paul did not have the problem with carrots that he had with radishes and beets. And I have carrots (Queen Anne's Lace) growing in the cracks of my pavement.

    Jim

  • 18 years ago

    That's it - moon planting in this climate is like playing three (or four or six) dimensional chess.
    Jim I remember that long ago radish thread :)

  • 18 years ago

    "Jim I remember that long ago radish thread :)"

    Yeah. It's nothing new. As I surfed for info this time that old thread popped up. It's like Alsheimers, when you get to hide your own Easter eggs, then find them.

    Still, I'm hoping we now have the answer and can lick this problem. Those who have never encountered it don't understand how frustrating it is. Radishes are supposed to be the easiest possible crop. In most places they are, but not here.

    Jim

  • 18 years ago

    Jim's suggestion about boron is quite viable. If you haven't got enough, you will have to add it specifically, as cover crops and compost won't provide it.

    If you have good carrot and poor radishes and beets, check your boron levels.

    Many parts of the country are very low in boron. But you will need a soil test to get accurate levels and advice on how much to add. Minimal boron levels for most crops is 0.8ppm; excellent boron levels are 1.5ppm to 2ppm, over that is excessive.

    Boron is unstable in the soil, and sandy soils have the hardest time holding it.

    (ppm+ parts per million)

    Sue

  • 18 years ago

    Sue,

    I found many references to boron deficiency with beets, but none with radishes. Since Paul has problems with radishes as well as beets, I am assuming boron deficiency is not the cause. Adding boron is easy but it can easily be overdone.

    Do you know of any info regarding boron deficiency in radishes? I am very interested because I am trying to understand how to grow veggies in my sandy soil.

    Jim

  • 18 years ago

    I can't grow beets.

    They sprout, get 1/2" to 1" tall and thats it.
    They don't grow, they don't die, they just sit there.
    Mocking me.

    Carrot no problem, radish fine. Beets are the bane of my garden. I will try the boron.

  • 18 years ago

    Hmmm... and I thought I was the only one that had occasional trouble with radishes. I have two theories regarding radishes: moisture levels and soil temperatures. Looking at my notes from last year, I have a query to self as to whether I need to water them daily. Some of the ones that bulbed had hollow areas and were "dryish", while many just sent down a tap root. For this year, I plan to keep them well watered, and mulch them fairly heavily once they're big enough.

    For kicks, I tried a summer crop in a shady location. Tap roots almost exclusively.

    Not to be discouraged, I tried a couple of fall crops. The Sep 1 planting did very well - most bulbed nicely and reached maturity. The Sep 15 planting also bulbed properly, although they didn't size up fully by the time the weather got cold and the days short.

    As a side note, one of the varieties I grow is "French Breakfast". Some turn out properly, and some turn out as red carrots. Go figure.

    Beets - this will be my first year, so no comment.

    Turnips - I grew rutabaga in two locations last year. My home garden (smallish but very fertile - clay loam) and at the community garden (fertile, dry, sandy soil). They grew well in the home garden, but I'm pretty sure I didn't water them enough. They bulbed up properly, but something (maggots?) got at the roots in mid-summer. The flesh was a proper yellow and the largest ones were comparable in size to what you see in the grocery store. The ones I grew at the community garden also bulbed up properly, but the flesh had dark brown streaks in it, which I attributed to boron deficiency after doing some internet searching. The community garden is very fertile, tending toward alkaline. My home garden is also very fertile, but is pretty much neutral.

    Potatoes/carrots - home garden produced an excellent crop of both. Community garden produced furry carrots (won't fertilize this year) and a smallish crop of dryish potatoes with cankers (will water more this year and acidify).

    My 2c worth...

    Cheers,

    Tim

  • 18 years ago

    Yesterday I talked with a fellow from the organic agriculture centre of the NS agricultural college. What he said - you could have knocked me over with a feather. I'd emailed him a description of our garden soil and practices and problems (* some of it copied below).

    He said it sounded to him like our garden had a carbon overload. Very good organic matter levels (5%) but much of it locked up in carbon, which are decomposed by fungi. Beets (and maybe radishes - we didn't talk specifically about radishes) - hate a fungal environment. They, and greens in general (and maybe radishes?) need nitrogen fast, in nitrate form. He said with our composting and mulching we had created perfect conditions for a forest floor. (I asked him did he mind if I kneeled at his feet while listening to him. He said Oh no you don't have to do that.)

    He suggested a quick fix of spraying molasses on our compost and mulches, to get lots of bacterial action going, and adding high-nitrogen materials like coffee grounds, worm compost, and possibly seed meals, although those are soon to be forbidden by organic standards if they are GMO which is all that's available here.

    He also suggested manure, and manure tea with molasses. He said that given our use of compost, seaweed and eelgrass, a boron deficiency was very unlikely.

    He asked whether we saw a lot of pigweed and lambsquarters in the garden, and I said we used to get a lot but there'd been fewer and fewer over the years. He said these weeds were indicator plants; what they indicated in our case was that nitrate levels were drastically low. He said beets were basically weeds, like pigweed. The weed seeds wouldn't even germinate in poor-nitrate conditions.

    He said a green manure rotation of clover, planted this spring and tilled in next spring before flowering, would make a good nitrogen fix, but not oats, left to winter-kill and then tilled in, because that would be yet more carbon.

    So, I hope he's right, because clover seed is cheap, and molasses, worm compost, coffee grounds and manure tea are pretty easy fixes. And I hope this is of some help to others here. Good luck with your beets!

    *"The oldest of our three gardens is sandy soil and the fertility seems to have been going downhill every year since we started 9 years ago, despite yearly additions of 4-5 inches of mulches (seaweed, eelgrass, leaf mold) and compost, and less and less tilling. Perennial flowers, berries and asparagus do wonderfully, and transplants do well, but other vegetables, especially greens, grow far too slowly. Also, carrots grow well but we can't grow beets beyond about an inch in diameter, if that tells you anything."

  • 18 years ago

    Paul, that's very interesting, because I have similar conditions to yours in soil and climate. Beets have never bulbed up well in my home garden, though they do in another garden with tighter soil and less organic matter. Radishes don't do as well as they used to, just as you say. Carrots do ok when I overcome the germination problem.

    I see some pigweed and lamb's quarter but not rampantly. I don't have any problem generally with greens - lettuce and chard grow quite well so perhaps my "carbon overload" isn't as severe. Point well taken on the inadequate thinning and soil drying out with radishes and beets.

  • 18 years ago

    Now that's interesting. We get so used to hearing about P and K when it comes to root crops we end up neglecting N as if it's not needed at all.

    As it turns out, while I usually mulch over the winter with just shredded leaves, I kinda went Starbucks crazy this winter, and dumped a bunch of coffee grounds on top of the leaves. And of course, when I removed the mulch a bunch of grounds ended up in my soil. So many, in fact, that I was wondering if I overdid it. But I'm definitely in a carbon overload situation, and everything so far seems to be germinating normally, so maybe it won't turn out to be a problem. That does remind me though that I really should get some radishes in when the weather warms up again...

    I should also comment on chard. The past few years I've been hilling my potatoes with leaves and/or straw to combat the Colorado potato bug (works like a charm I might add!) Anyway, after digging up my spuds last year I tilled the leaves (which were essentially leaf mold) into the soil and then transplanted out some chard and kale into this area (without any fertilization). The kale didn't do much (but it was a dwarf variety and my first year, so I didn't know what to expect). It now appears that a good dose of N may have been in order. But my real point is that the chard went *gangbusters* - I had chard the size of bed sheets. Well, maybe flags :o) And as above, my lettuce always does very well as well...

    I guess the big question on my mind now is whether or not coffee grounds or seed meal will release their N fast enough to benefit radishes. I'm thinking that at this time of year possibly not. Might be time to pull out that gallon jug of fish emulsion I bought yesterday :o)

    Cheers,

    Tim

  • 18 years ago

    Just a thought: sandy soil may have trouble holding enough moisture. Radishes grow quickly, and need constant, regular moisture. Do you see any wilting problems?

    Sue

  • 18 years ago

    Sandy soil is definitely part of the problem, I think. I'm picturing our garden now as sand+carbon.
    We are zone 6 but have pretty cool summers and long winters, maybe colder than where you are Pat, but sounds like similar conditions. The cool climate must contribute to the slow breakdown of carbon material into the soil.

    Our lettuce crops are not too bad, they just grow far too slowly.

    Something else the guy said was that annuals like beets and kale and lettuce don't develop mycorrhizal relationships with the soil, while tomatoes and potatoes (and carrots?) do, helping them access nutrients. I'm no chemist so I hope I'm repeating all this correctly.

    He said we could send a soil sample to PEI to have it tested for C:N ratio, for $20. 12:1 is good ratio.

    Tim, I found picking beetles off the potatoes every day and dropping them into a can of soapy water made an enjoyable adventure. The summer after I did this I found specimens, for the first time, of that bizarre creature the potato beetle larva. Picked those off too and had no beetle problem last summer.

    Can you collect coffee grounds from all those London coffee shops? What about that coffee bean place in the market downtown?
    Nearest Tim Horton's is 1.5 hours from here...

  • 18 years ago

    Yeah, we do almost always get some hot humid spells in the summer that the Maritimes typically don't, or not as hot or as long. But it often aligns with low rainfall and of course high evaporation, so I don't know that much breakdown occurs during that period. I think most of it happens not during the growing season but when the ground is not frozen, because that's when the light soil is well saturated and just warm enough for insect and microbial activity.

    Spraying the mulches and other ground-covers with dilute molasses sounds like a good idea. I've got a gallon of it that's been sitting around for years.......

  • 18 years ago

    You know, I was thinking some more about what the horticultural expert told you. While I don't doubt that perhaps lack of microbial activity and too much fungal activity (is that a description of "carbon overload"?)may be why your beets don't bulb up and possibly explain your other problems as well, I don't entirely buy into his analogy of having created a perfect forest floor, which I take to mean that you have supposedly starved the garden of nitrogen by piling on so much crude OM. It's bound to turn into good fertility sooner or later, as exemplified by the fact that typically when a forest is freshly cleared crops grow very well without any fertilizer for a few years. That was my experience when I cleared my garden site of mature trees and thick brush and tilled soil from a good hundred years of falling leaves and branches, and I've hardly matched the results since.

    So I guess if we are going to pile on the stuff - to mimic nature as if there were still a forest above the garden - we have to figure out a way to compress time. I suppose that's what the fellow was driving at, and it's also what a big composting operation does.

  • 18 years ago

    The guy never saw our garden first hand - he was going by my description. I superimposed what he said over my mental image and knowledge of the garden to see if and how it matched, and it seemed brilliant. Although I wondered why all the seaweed and mature crab-loaded compost we'd also loaded on wouldn't boost the N levels. Anyway I was hoping to get some other points of view so thanks Pat. It's still a (slightly) open question in my mind.

    A forest floor has been rotting and accumulating OM for a long time...Our garden was worked as an organic garden for about ten years, then ignored for about two, before we bought the place. The fertility was probably the best that first year, after turning it from meadow to garden.

    'Compressing time' means giving the soil that intense shot of nitrogen?

  • 18 years ago

    I'm too busy chasing after cucumber beetles and slugs to add CPB to the list! Although, in all fairness, I do have the slugs under control. If only I could come up with a magical way to banish the cucumber beetle....

    As to coffee grounds, I decided last fall to visit Starbucks daily for the grounds. It's within a couple of blocks, so I don't burn much gas to go there. Anyway, over the winter I was the only one going after them, so I usually got 2 5gal pails a day. I've been spreading them around everywhere, and stockpiling them as well, so needless to say, I'm well supplied. And they recently started brewing fresh every half hour, and suggested that I bring in a 3rd pail every day. So, it looks like this is going to be the year of the coffee grounds (although others come in occasionally for grounds this time of year). I'll have a better idea come October how useful they are. They don't break down too quickly this time of year, and a pile of leaves mixed with grounds isn't heating up much past ambient (whereas my composters are cooking away) so I'm not convinced they're useful for hot composting, but we'll see.

    Anyway, as it pertains to this thread, I plan to mix a fair amount into the sandy soil at one of the community gardens when it opens in a couple of weeks, and we'll see what kind of difference they make, if any.

    Cheers,

    Tim

  • 18 years ago

    Tim, here I spent a winter of happy amnesia about cucumber beetles. We never had them before; last spring we heard a rumour that they'd arrived in our area, and in summer we found a dozen. Now there's a frightening pest to deal with. Thank you for reminding me! Let's hope it's a bad year for them, not us re: them.

    Coffee grounds don't seem a particularly hot N source to me but then Tiffy in southern NS, who's usually on the soil forum, says she keeps her compost piles going all winter on a diet heavy with them.

    So Pat, the guy just called back with follow-up thoughts on our garden issues (what a fine civil servant. He was on his cell phone, heading out on a farm call). He said that since annuals, like greens and annual weeds, don't form fungal associations, it would be a good thing to till lightly in their area to incorporate organic matter and get bacterial action going, even if it's sandy soil, as long as we keep OM levels up. He said the first year forest floor is cultivated there's a big flourish of bacteria from destroying the fungi, which is why crops are good.

    The longer the life cycle the likelier a plant will form mycorrhizal relationships, ranging from annuals - none - to tomatoes and potatoes to biennials, perennials, shrubs, trees. This makes sense, I just never thought about it that way before.

  • 18 years ago

    Which explains why potatoes and tomatoes will thrive in quite coarse stuff like partially broken-down leaves, and why tree and shrub growers typically pot up in chipped bark with a bit of chem-fert thrown in........