Radishes

[Walleye Guy]

My family generally has a very successful garden. The one veggie that has caused us problems the last two years is radishes. In both years the tops of the plants got real green and full but there was basically no radish under the tops of any of them. Last year I chalked it up to bad seeds. Now it has happened again. Obviously there is some other type of problem.

This is a well established garden where I have had no problem growing radishes or any thing else in the past.

Anybody have any ideas on potential soil problems etc that could cause radishes not to grow?

[3pronghook]

i have consistent success with the red radishes. i make sure to thin them to give them room to grow. they like lots of water. as for the longer white radish...im ready to give up. i just pulled them all last night because the greens were staring to flower. i found maybe 4 or 5 that were big enough.

[Powerstroke]

I am no expert on veggies, but I've heard this problem many times before.

This tends to face two different issues. Number one is a choice of fertilizer always comes up. Most people use too much Nitrogen and not enough Phosphorus and Potassium. The latter two are mroe important to root development which is what carrots, radishes etc are. Nitrogen is good, but high N ferts just give you bright green leaves and not much root growth. Its all in how the plant processes the different foods.

Another thing is watering. Just like lawns, if you do frequent waterings, you develop shallow roots cause they don't have to seek out water deeper in the soil. WHen growing roots and tubers, its good to use longer, less frequent waterings early on to train the roots to reach deeper into the soil. Towards the end fo the season when roots really start growing, then you can increase waterings to get thickness and bulk to your roots.

Thats my .02. I hope it helps.

[harvey lee]

Radishes love softer soil.If you have a smaller area where you plant radishes,add some peat to the soil.I know a veggie grower that does it commerically and all he will use is peat ground and he gets beautiful radishes.

[Steve Foss]

Yes, all root crops do better in light soil that's been turned over and broken up. Radishes need less than big carrots, say, but still like it light. And soil that's light will allow them to mature quickly and with no barriers to root development. Plenty of humus in it will allow water retention, which is very good. Radishes that grow uninterruptedly and quickly will be crisp and sweeter. Those that sit in the ground longer and take more time to mature tend to be woody and sharp.

I don't necessarily see a fertilizer issue here. If there is one, Powerstroke is on the money. But when I've seen radishes that don't develop the radish very well or not at all, it's almost always because, after planting all those tiny seeds (you pretty much can't space them out well) and watching them germinate, the person doesn't thin them out when they get an inch or so high.

If you don't thin them, the roots are so close together and all competing for the same nutrients that they don't develop.

You can pull them to thin, but that damages the roots of the plants nearby, so I always thin by cutting the tops off at the ground with a scissors. For the smaller varieties, when the foliage is an inch or so high, I cut them off so each remaining plant is about an inch apart, sometimes two inches. If you leave them an inch apart you can pull some of them as they reach the smaller edible size, which will leave the remaining ones room to get somewhat bigger.

Since you've grown radishes there before that did well, this may not be your problem, however, and I'd definitely go with the fertilizer. Very healthy leaves with tiny or no root crop can be a pretty classic example of a fertilizer imbalance leaning too far toward nitrogen. In fact, fertilizing with phosphorus and potassium is just a good idea anyway, as most soils have plenty of nitrogen for the quick-developing radish. Wood ashes are a good source of potassium, and they repel root maggots.

Also, radishes do not like the heat of mid summer. They are best planted and harvested early, and if you leave a few to bolt and grow seed heads and then collect the seeds, you can put in a second crop at the end of August (this depends on where you live) that will appreciate the cooler weather, so you'll have more radishes in fall.

Also, unless you've planted an elongated variety or a giant variety, they only need moisture down two or three inches, so shallow waterings aren't a problem for radishes. And if you go too long between watering, the burst of water will push them into a growth spurt that literally has them cracking out of their skins. Any time you see radishes with those splits in the skins, it's because of intermittent watering with long dry periods in between.