I've recently planted two year old (approx 5 ft tall) cherry trees on my allotment. I am planning on fan training them, so won't be getting any/ much fruit for a few years. Should I put grease bands on them?
As you will be fan training them, ants will have many more ways to get onto the trees to do their 'aphid farming' than just by climbing up the trunks, so it's probably not worth using grease bands. I would just keep an eye on them (particularly the growing tips) and treat any aphid attacks on the young leaves as and when you find them.
If you are fan training using free-standing posts and wire rather than against a fence or wall then a grease band on both the trunks and each post might be worth considering.
thats really helpful, many thanks.