There is a tip I can give from the commercial world, really as a means of shutting the stable door after the horse has bolted.
If you have not been able to protect your fruit buds in preparation for Jack Frost's snap arrival, you can take a leaf out of the commercial grower's book who will use water to minimise damage.

You have to be up early before the sun hits your fruit blossom, but spraying with water will heat the frosted blossom enough perhaps, to stop the cell structure in the flower from being destroyed.
This, of course, can help ornamental blossom in the same way. It might be worth trying it out on camellias or magnolia should the worst happen.

It can be that in taking the coldness out of the plant the water freezes on the stem. It's a strange concept but as I say, commercial growers have used the technique for years.
Blossom time is very important for any plant from which we are hoping to pick fruit later in the season.

Conditions have to be right for pollination to take place. Some plants such as apples will need a pollinator tree nearby from which insects will transfer pollen.

All being well, the pollen grows inside the flower and fertilises the ovary, thus "setting" the fruit.
There are other things emerging at this time of year besides blossom.
Eggs will have been laid by moths which hatch in time for the caterpillars to emerge and make their way onto the newly-set fruit.

At this stage the blossom is still on the tree, and by reckoning that 80 per cent of petals fall, you can use an insecticide to see off these pests while they are on the move and before they burrow into the apple.
The codling moth will soon be about ready to use apples and pears as a source of food for its young.

You can reduce the problem by using a special moth trap. It is made of 'Correx' in the shape of a tent and contains a phial of pheremone which is a female hormone.
The male has a whiff there is a possibility of mating, from potentially a very great distance, and is attracted into the trap. This is coated with a sticky substance, thus the hapless male is unable to have his wicked way and comes to a very sticky end.

Commercially, these traps are only used as an indicator that a problem may be about to occur and the necessary action can be taken in the form of a spray application.
In the garden these traps are often enough to protect one or two trees without the need for spraying.

It may ward off the worst thing that can happen, that is finding a maggot in an apple, and even worse, finding half a maggot of course!
Later, as the fruit grows to marble size and beyond, frost can still rear its ugly head, causing damage to fruit. This will manifest itself as cracks in the fruit as it swells, so there is still a need to keep an eye on the weather ahead.

Beyond that there are birds and wasps to contend with, but usually when you see these attacking it is time to harvest.
It's a bit like running the gauntlet for apples and pears to mature into usable fruit, but isn't there something rather satisfying about eating straight from the tree?

Having pollinating trees nearby is not usually a problem, as insects will travel many metres looking for pollen and do not worry about a neighbour's fence.

With modern dwarf varieties and with the different methods of training, up a boundary wall for example, there are few gardens that do not have room for a fruit tree or two.