I have very long finger nails, which I look after and always wear nail-polish.
Here are 2 tips to help look after them, well 3 actually,
No 1:
Wear gloves - if you are like me and never wear them, and dig your garden with bare hands, follow tips 2 and
3
No 2:
Before gardening, gouge your nails into a bar of hard soap, and leave it there for the duration.
No:3
When you have washed your nails after gardening, then use a spare toothbrush and gently rub your nails with whitening toothpaste and all the discolouration will go.
I am full of (mostly useless) information, regards Mrs Bouquet