In the context of English landscapes, "mature" usually refers to:

: A popular dwarf heirloom variety known for its compact size. 3. Mature English Flora

There are several English heritage plants that have specific names, though none are "mature thumbs." You may be thinking of:

: The English Garden highlights heritage varieties like "Fat Lazy Blonde" lettuce or specific heirloom peas and beans.

: Significant features of the English Countryside , such as ancient oaks or mulberries.

: Gardens managed by English Heritage that preserve historic food timelines and ancient plant species. 4. Cultural Gesture

Could you clarify if this term relates to a , a cooking technique , or a historical reference ? Knowing the context (e.g., a book or a specific region) would help in providing a more accurate report. A timeline of food in Britain - English Heritage

In a non-agricultural sense, a "mature thumbs down" is sometimes used to describe a dignified or restrained expression of disapproval, as opposed to more aggressive gestures.