Two allotment owners believe they were targeted by jealous rivals over their success in a competition.
Retired bus driver Roy Brookman, 78, and former police officer Bill Boag, 64, were devastated when their plots in Sidcup were destroyed by a blaze.
Mr Brookman said: “Both our sheds were totally burned to the ground — it’s so depressing. We don’t know what happened. There could be jealousy going on. We can’t say anything and accuse anyone but that’s what we think.”
The plots were burned when they got first and second prize at the Bexley in Bloom competition.
Mr Brookman added: “Four years of hard work destroyed. So many memories.” Ten firefighters prevented the blaze spreading to the entire allotment site.
Bexley police said they are treating the blaze as suspicious.
