The fennel bolted. I turned my back for, ooh, 15 days – a hot weekend, then a trip abroad and a couple of days in London – and when I looked at the fennel again, it was different. Not wrong, exactly – it was still green and fluffy and sprightly – but there was something not right. The bulbs seemed to be growing longer rather than fatter. I mulled it over for a couple more days; worried a bit; read all the books; dug out a plant and tried to eat it (tough); and then I chopped off three of them and took them to see our expert, Sarah Wain at West Dean Gardens, a horticultural A&E trip.

Sarah barely glanced at them and said, “They’ve bolted.” How? How how how? I loved that fennel. I did everything I should have. It was my favourite and now it’s barely even good for flavouring a bit of sauce.

Sarah asked whether I raised my plants in modules as she had advised, and then transplanted them (hers were planted at the start of March, before I’d even got the seeds). No. Straight into the ground, I put them: that was when I was having trouble with the lettuce modules, you may remember, there was lots of fiddling around with pricking out and dying, and I couldn’t be bothered to get involved with any more modules. She asked me when I planted them. Beginning of May. Hmm. Probably too early for sowing directly into the ground, unless I used a bolt-resistant one such as “Cantino” – the soil temperature needs to be at least 15C.

So, did I add seaweed fertiliser? No. Water them assiduously? No!

Doesn’t fennel grow in a hot climate? I wasn’t too worried, and it all looked so fresh and good. Well, yes, above ground it might have… but underneath, dry roots, you know. It has an instinct to preserve itself for next year, she said, so it gets on with the next bit. It bolts. I was almost proud by the end of it that I had bred something with such a streak of independent self-determination. But I was also really annoyed that my own streak of dogged independence (I know better) had mucked it all up.

Expert advice

Bolting – when a vegetable plant runs to seed – is triggered either by a cold spell (in endive, Swiss chard and turnips) or by changes in the day length (in lettuce, spinach and radish cultivars). Hot, dry conditions can also encourage it, especially in annuals like rocket, so keep crops watered, and sow new batches at regular intervals.

With cold-sensitive plants, delay sowing until the soil temperature reaches at least 15C.

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