If your sprouts are looking a bit loose headed, like the ones pictured here, then don’t be too disappointed… firstly, you can still eat them. Just harvest them as normal and slice them up before cooking, then serve them and call them “shredded sprouts”! Secondly, it probably wasn’t your fault.
If the sprouts on a plant start to form while the weather is too warm, then they do tend to produce loose heads. It may be that some of your plants that have sprouted a little ahead of the others, and since it has been warm these early sprouting plants have loose headed sprouts. That’s not to say that the plants to follow will also produce loose heads. In theory, if the weather cools before they start to set their sprouts, then the next batch to come through will be more like the sprouts you imagine seeing on your Christmas dinner plate!
Either way, we should warn you that sprouts are very popular with slugs, sparrows and pigeons…so when they do start to form, be vigilant!!