This one has me baffled. The clue is “Why leaves aren’t green?” (5,6,4,2,5).
The answer looks as though it must be MONEY DOESN’T GROW ON TREES, and all the letters I have so far are consistent with that - but can anyone explain why? Please?
There was that part of the Hitchhikers' Guide to the Galaxy where the Golgafrinchams were using leaves as currency, and had to use defoliants to restrict inflation?