The Garden Museum on London's South Bank reopened in 2018 and has a very good cafe. You can sign up online for their newsletter.
London Gardens Check
out this online site for gardens and green spaces all over London,
including some you might not know about in our local area.
Royal Botanic Gardens Kew. Only 30 mins from Central London. There are four gates which can be accessed by rail, bus or river.
The Chelsea Physic Garden was established as the Apothecaries'
Garden in London, England, in 1673 by the Worshipful Society of
Apothecaries to grow plants to be used as medicines