Give plants enough time to start to grow before you dig them up.
Many plants show signs of dieback after such a severe winter. The easiest time to check for damage is in late spring when new growth should start. Take care to allow your plants enough time to start their regrown before you dig them out as after severe weather they can sometimes be slower to start their new growth.
Trees and shrubs can be checked by scratching off a little bark with your nail. If the stem underneath is green or cream then that stem is still alive. If it is brown then it is dead and ready to be pruned off. However, shrubs like hardy Fuchsias can die back to their base and can regrow from shoots underground. Look carefully around the base of the plant to see if there are any signs of new growth. Plants may need 3-4 weeks longer than normal this year to start into growth.
Hopefully the old growth may still be standing on your herbaceous perennials and this will have helped to protect the plants roots. If your plants were covered with a thick snowfall they will probably be fine. The snow worked like an blanket and insulated the plant roots. Again carefully cut off last year's dead brown stems and look carefully around the base. Hopefully new green shoots will be emerging. If not yet, be patient and give your plants 3 or 4 weeks longer than usual.
Plants that have survived may now be suffering from damage by small creatures. Mice, shrews and voles are currently doing a lot of damage in the nursery. Plants already showing flower buds such as Barnhaven primroses are being particularly targeted. Difficult to protect apart from lifting up higher if the plants are in pots or covering with small holes mesh or wire. Bulbs can also be targeted especially crocus and Iris reticulata which seem to be particular favourites of mice. If you have any other tips then please e-mail and I will add them.