All you can do is ease them into it. They definitely taste completely different. And its not just a case of me being wistful for a long gone yesteryear through rose tinted taste buds...(i'm only 31)- the decrease in quality has been quite rapid.
I think intensive farming and full flavour just don't cohabit, and most of the veg we buy now is very, very intensively grown, and that wont change any time soon.
Carrots and tomatoes are the two things i notice the BIGGEST difference with shop bought for flavour. No comparisons at all. And much of the tomatoes we buy have been picked before they are ripe, and ripen instead while in transit - and never develop the flavour they should, or could if sun ripened.
Maybe look around for some milder flavoured varieties of cabbages etc?
And wash that mud off before they see it!!
(and the caterpillar nibbled leaves!!)
A dig for victory campaign would be exceptionally common sense, given the economic climate... we import far too much food. Not to mention waste too much food (and a large part of that is having to buy protectively packaged bags of veg that go off as soon as you open them... Anyone else notice how your home grown carrots keep for ages, but the shop ones go black/soft/bendy or sprout in a couple of weeks?)
And dont get me started on cucumbers... I had one that kept crunchy for 3 weeks in the fridge last summer that a neighbour gave me. (i was savouring it slowly) Try getting 3 days out of a shop bought one!?
The supermarkets make more money by selling you more than you need, that will go off quickly and need to be replaced the following week.... grr rrr rrr