The buds which aren't opening, are they withering or going brown, or do they look perfectly healthy still? Is the second tree in a shadier or windier or more exposed spot (if the buds are healthy).

thanks for the answer. the buds still look very healthy. the two trees are about 2 yards apart. the one that has flowered gets a bit more sun that the one that hasn't.

Ah, that might be why then, specially as the temperatures are pretty low. Keep an eye on the blossom - if they start to wither, but don't fall, you will need to carry out remedial treatment,but hopefully, they'll just open later on.

thank you. I am checking regularly. If it comes to "remedial treatment" what should I do?

Don't worry about that yet - it involves cutting off the affected ends of the branches before it spreads (look up Blossom Wilt if you're curious) but if the blossom does start to wither, add that info to this thread - that way, I'll get to see it.

Hello Again. Well its nearly one month later and the buds still haven't opened on the one tree while the other has nicely maturing fruit.

There is no sign of any rot or anything on the buds or branches.

any ideas?

If the buds look healthy, as you say, just wait - the weather is appalling for the time of year, even just from a temperature point of view.