Cowslips (Primula veris) are abundant in a section of Butts Close, the town common in Hitchin, Hertfordshire. The area was used for archery in Medieval and Tudor times- the butts in question being archery butts.
 Like a good many municipal parks there is now a policy of managing part of it as a grassland ecology. I don't know if the Cowslips are a relic population that has made a comeback or a more recent introduction for biodiversity. Certainly one still sees wild colonies of P. veris here and there on chalky grasslands in Hertfordshire though this is a much diminished habitat in the county.
 Around the margins of the park there is plenty of Cow Parsley, White Deadnettle, Garlic Mustard and Stinging Nettle. These wild things don't need much encouragement; it's more a case of not discouraging them.
 Thankfully the municipal mania for spraying and flaying weeds aka wildflowers is on the wane. Even more so now the country is in a state of lockdown- possibly wildflowers and wildlife will benefit from the present emergency.