I have just turned my “active” compost heap, which has received all the Guardian biodegradable bags since they were introduced last year. I am pleased to say the older bags are barely recognisable and are well on their way to forming nice new compost. David YatesEccles, Greater Manchester• Can I join the search to find the oldest marmalade-making Guardian readers (Letters, 31 January)? Pat WakelingNottingham• You can’t grow sponges from seed – they are animals, not plants (Grow your own sponges, G2, 29 January). Jocelyn RoseMilton Keynes• Join the debate – email guardian.letters@theguardian.com• Read more Guardian letters – click here to visit gu.com/letters• Do you have a photo you’d like to share with Guardian readers?

Source: The Guardian January 31, 2020 17:15 UTC