On balance I have a very hard time getting my veg to grow proper “bulbs”, or how one would put it. Beetroots, radishes, kohlrabi or turnips produce lots of leaves but no harvestable bulb. One supposedly has to be careful with not having too much nitrogen in the ground as it produces lots of leaves but not much else. Too much nitrogen is not a problem in my garden. I asked in a garden centre recently what they thought could be the problem, and they suggested potash deficiency, does this sound like a reasonable assessment?