I have limited garden space and decided to plant turnips, radishes and carrots in above ground planter boxes. I used a mixture of bagged garden soil, compost, and bagged cow manure. Texas has a clay type soil and when I planted these vegetables before in the ground, I had no problems. This year I had plenty of green leaf growth but the roots did not develop. They stayed thin and did not expand. I applied a 10-10-10 fertilizer during the pre-summer growth season. The same thing happened to the fall plants. Any idea of what could be causing the problem? Insect damage was very light this year due to the past drought and no evidence of disease was present.
Turnips, Radishes, and Carrots
Certified GKH Gardening Expert
If you are noticing more top growth and little to no bulb formation, it is likely due to a fertilizing/nutrient issue. While a soil test would allow you to know for certain, it may be that you have too much nitrogen and too little phosphorus. Lots of nitrogen will result in plenty of leafy growth but if your soil is lacking phosphorus, there will be poor root growth. I would add some more phosphorus, like bone meal, to the soil.