Embee
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Joined: Thu May 18, 2017 12:52 pm

Radishes don't grow radishes?!?

Every time I've tried to grow radishes, they start out looking good. But instead of going on to produce a radish, they grow into a little curlyque just above soil level and what little they develope under the soil is thin and woody. Out of a hundred seeds, I might get a half dozen edible radishes about the size of the end of my thumb.

Type of soil, variety of radish, time of planting, watering variations -- nothing seems to make any difference.

What am I doing wrong?

imafan26
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Location: Hawaii, zone 12a 587 ft elev.

My guess is too much nitrogen in the soil and you probably have an acidic soil.

If you are growing in the ground. Add more compost and chicken manure about a month before you plant. If your soil is not already phosphorus rich you can add super phosphate or bone meal at planting time to boost root growth. I add 4 inches of compost and a half inch of chicken manure.

Radishes will bulb mostly above the soil and only a third below but they do have a long tap root. Plant radishes to 2-4 inches apart . They should be spaced so when the bulbs are fully mature they are only barely touching or have a little space still between them. If they are crowded they won't bulb out well either.

Some radishes can mature in 21 days so they usually don't need a boost. Daikon takes 70-90 days so that benefits from a boost of 10-30-10 or 5-10-10 or bonemeal+ fish meal when they are about 4 weeks old
In pots, some people add compost, lime and bone meal to the potting mixes. I don't have luck adding compost, or manures in pots, but it may just be because of what is available to me.
Here is an article for potting mixes if you want to make your own.
https://articles.extension.org/pages/209 ... mix-basics

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jal_ut
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Joined: Sun Jan 18, 2009 10:20 pm
Location: Northern Utah Zone 5

Hi Embee, welcome to the forum. If you will add your location and zone to your spec sheet it will help us to help you. Are you growing in pots? Here I grow out back on the land that was here when I bought the building plot. It had been farmer's growing land for many years. I just go plant radish seeds. No special prep. Just poke some seed in the ground. They are a cool weather plant so plant early.

Embee
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Joined: Thu May 18, 2017 12:52 pm

I'm close to the southern edge of zone 4 in MN.

My radish attempts have been in an assortment of containers ranging from bathtubs and stock tanks to wash tubs and large dishpans filled mostly with decades old rotted horse manure mixed with varying amounts of sand. It's beautiful and grows everything but radishes.

Planting in the ground is more work than it's worth because of heavy, zero drainage clay and quack grass, plus containers are easier to protect from critters who think somebody put out the buffet just for them.

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Lindsaylew82
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Location: Upstate, SC

Yep. Too much nitrogen in all the poo! If it grows great greens, it doesn't usually grow great roots. I would take one of your pots and treat it like Imafan said. Maybe without the chicken poo. No more poo for you! :()

When a fertilizer is mentioned, those 3 numbers, 10-10-10 are for N-P-K. When growing root crops or bulbing plants, you wanna have a higher P number in the N-P-K. Imafan mentioned Phosphorus, that's the "P". "N" makes lots of lush green growth. The bone meal that she mentioned is great on the P. It takes a good season for the P in bone meal to be available to plants. Amend one of those beauties now for next years radishes.

You can amend a small 2x5 portion of that clay yard with peat moss, some of that gloriously composted manure, chopped leaves and grass clippings. Use a pitch fork to sink deep into the clay and just wiggle the back and forth. I wouldn't till it, just hand turn those things in. Plant something deep rooted like corn in it this season, and then mulch it with grass clippings and leaves this fall. Clay is tricky to work with, but it holds nutrients (especially "P"!!!) well, and I think it eventually grows a great garden. Next season you should have early, sweet and crispy, fat roots!

imafan26
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Posts: 13962
Joined: Tue Jan 01, 2013 8:32 am
Location: Hawaii, zone 12a 587 ft elev.

If you are planning for next year on acidic soil, you can lime. Liming takes 6 months to change pH. Chicken manure also raises pH by about half a point but you can plant something else in that now. I don't use manures and composts in pots but I do test my soil. In the plots that have a lot of alkaline compost and pH of 7.8 (no liming) but chicken manure was added years ago, I get good root crops. In my acidic plot pH 6.0, I get really good tomatoes, but almost no roots in root crops. All the plots get nitrogen and compost but the acidic plots hold on to it longer. My phosphorus is high 250-1600 ppm (I need 37 ppm), so the only fertilizer I use is sulfate of ammonia. The only real difference that has mattered has been the pH. Beets are supposed be good in the range of 6.2-7.0.

It might be better to use an organic fertilyzer since it is usually nitrogen poor. You will have to supplement nitrogen at around 4 weeks. Bonide garden rich vegetable food 5-10-5 might be a good choice. Try to get a potting mix that contains mycorrhizae like Promix.



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