Ramsons (Allium ursinum) aka Wild Garlic are flowering at the moment. I planted them in two of the damper, shadier spots in the garden which suits them. Native to the UK they can be found in many woodlands- and make them smell pungently of garlic.

 

 Spanish Bluebells (Hyacinthoides hispanica) were here already when I arrived and come up every year. I'll leave them be as they do no harm in the urban context but ecologists take a dim view of the way they cross breed if they are in proximity to ancient populations of our native Bluebell (Hyacinthoides non-scripta). NB I wrote a long entry on this topic 21st. May 2017.
 I have planted H. non-scripta in the garden but they flower a bit later.

 Another wild onion/garlic: Three-Cornered Leek (Allium triquetium). This one is non-native and frowned upon by ecologists, in fact it's illegal to plant this species in the wild. It spreads very vigorously and out competes native species in their natural habitats. I've planted a few in the garden (not illegal) and will keep an eye on them. Like Spanish Bluebells they weren't born to bad, it was society that made them that way.
 I sometimes see neglected gardens that have been colonised by them but these are unatural habitats to begin with. I saw a front garden recently that was carpeted with Three-Cornered Leak and Green Alkanet to very striking effect. Actually if someone isn't going to do much with their garden I'd rather see that than tarmac or astroturf.