I saw a news item that said the the UK would have a bumper crop of asparagus this year -- 20% greater than average, if I remember correctly. Good news for you, UK1.
Here in the Chicago area, it's not quite yet the season for (relatively) local asparagus, so the price is still US$2.99/pound (£4.45/kilo?) or more. When it gets down to $1.99/lb (£2.90/kilo) or less, which should be by early May, we'll know it's asparagus time.
Meanwhile, I'm hunting around for fava beans ...