Now is the time to dead head daffodils and narcissi, but leave the foliage as the food in their leaves returns to feed the bulbs for next year. This also applies to hyacinths (in the ground or in pots). One narcissi yet to flower is Pheasant’s Eye, a very old variety with a lovely perfume. Tulips, too, will need dead heading after flowering so that the bulb isn’t putting energy into producing seed; if you miss one, the seed heads can get quite large.
Penstemon are ready to cut down now as new growth will be appearing at the base of the plant. I have lost a few penstemons this winter and so I will be taking cuttings. Hostas that are getting congested (especially those in pots) will need splitting and re-potting. A sharp spade is the easiest way to split them.
Potted plants are prone to vine weevil; the white, horseshoe shaped grubs eat the roots of plants so it is worth watering with Bug Clear Vine Weevil Killer. You can also use Nematodes but it is an expensive treatment. Use a heavy boot to deal with flightless adult beetles which have a very hard exterior!