Fruit tree flower buds
What can I do to trigger production of flower buds on my 6 yr old espaliered Hetlina and Monty's Surprise apples, please? I read that a shallow knife cut around the lateral branches coming from the main trunk (at the time when flowerbuds are expected) should trigger the development of the hormone responsible for flowerbuds. I tried it this Spring, but it hasn't had any effect,
Outside United States
The cut you are talking about is called "ringing" or "scoring". Another technique that can improve flower induction is bending the branches to or below horizontal. However, all of these have to be done before flower bud are initiated, not just before they are expected. Flower buds are initiated in June for the following year. So, if you only did the ringing this past spring, even if it was effective, you wouldn't see the results until next year.
Your lack of flowering may also be the result of using a non-precocious rootstock (do you know the rootstock that the trees are grafted on to?) or excessive vigor that can result if they plants are getting too much nitrogen. How much new growth are you getting each year? If new shoots are more than 12 to 15 inches long, then you have too much vigor for flower bud initiation. Excessive vigor results from using the wrong rootstock and from too much nitrogen fertilizer.
Thank you for your detailed reply. I ringed too late, I know that now. Also, I couldn't find info on how deep to score the branches (and how wide to make the cuts). I don't know the rootstock (planted by the previous owner), but the growth was excessive (1 metre plus long). I have only used compost around my trees and not an excessive amount. I'll see what happens next year. If they don't produce fruit, I'll remove the apples and replace them with Stella cherries which produce very well in my area.