How to stop birds from nesting in garden
Legally, there's nothing you can do to step nesting birds once they settle, but you can focus your efforts on stopping them in the first place.
How to stop birds from nesting in gardens would be to simply make the potential nesting site less inviting, or use plastic mesh netting to cover trees or a hedgerow. What is a better option than that is simply picking away nesting material as its being built, usually over a 2 week period, until birds get the point.
In an effort to stop birds nesting in your garden, its suggested to do so outside the nesting season, as to protect birds in this short period.
In taking onboard my advice then its best to wait until September or later into autumn as birds are unlikely to be nesting.
Its also important to remember active nests, be it a natural nest built in the wild, or a nest built inside a wooden bird box,- are protected by law. To remove or block off an active nest would be against UK law.
In following my advice to stop birds nesting in your garden then, do so that doesn't violate the rule of law - in which can lead harm or death to parenting birds and their nestlings.
Gently as it goes then as you make regular visit to area wild birds have their eye on in spring or summertime only. In this time it would be acceptable to remove nesting material in the process of it being built.
Once the female - who birds the nest - realises its disappeared every time she comes back - she'll hopefully soon get the point and move onto new nesting grounds.
I would recommend to stop the actual build of a nest ever getting off the ground, by covering welcoming nesting sites in your garden. It could be a tree or an hedgerow that would be most inviting, or the likely location a nest is created.
What you need to do then is simply cover up any natural coverage in your garden with use of plastic, durable large mesh netting to stop birds gaining access.
Regular visits to trouble spots
As wild birds would probably choose to nest in any sort of tree in your garden, its probably this area you'd need to focus on most.
Regular visits to this tree by you is a good start as you continue to disturb them, thus making it harder for them to settle.
Of course to continue to visit this area in spring when common garden birds begin to make a nest, is not always going to be an option.
It could be the tree is too tall, the weather is wet or cold to bother - or perhaps the nest is positioned to high to really make any difference.
What you can do then if the tree is low enough for you on the ground, if using a stepping stall or a ladder, to pick out the nesting materials the nesting bird would be creating over a period of one to three weeks.
Hopefully, this bird would get the point and move onto new nesting grounds.
Cover tree with netting
It really can depend on the girth of the fledging tree, but another option can be use of netting to cover over the full tree.
Its a two or three person job to initially set it up, but the idea is to stop any potential nesting birds from ever making a nest.
Now, to cover a tree with netting can be controversial, but its not a bother providing you never, never remove it or trap a nest on the inside of the netting.
On a different note, mesh netting can be used over a tree to prevent birds picking fruits.
However, this light mesh netting must cover up the whole tree with a knot or fixing coming to the bottom, around the tree trunk where it would be sealed.
This must be done in such a way no bird can get beneath it to nest - because if they do there's no way you can disturb a nest thereafter.
Trim to its bare bones
Come spring time birds begin to nest in the tree within your garden; it would be when it begins to blossom, with an attractive leafy cover where birds like to nest under.
I would say to cut back these leafs to prevent it being so inviting, but it can be possible to see birds still nest in such a bare tree.
But what you can do for a tree that is beyond its best, so needs a major clean up, is you can get the branches cut back into a more bare-bones tree.
Almost skeleton like but in due course new branches would begin to blossom again.
What you would be left with is the tree trunk of course and all thicker branches. However, the smaller, thinner branches would be gone - thus making it more difficult for birds to lay the foundation for a nest up the tree.
Replace or cover hedgerows
British birds such as robins, wrens or blackbirds don't like to nest too high off the ground so a tall tree, or a tree of any kind would not be within their sights.
And while I base this information of where to site a bird box in the garden, its species such as these that would prefer a hedgerow.
To stop birds from nesting in the garden then you may also need to focus on bushes, or more importantly the inviting hedgerow running a length of the garden. It can also relate to thick ivy growing up a trellis or brick wall.
I wouldn't recommend cutting a hedgerow back unless you plan to replace it with a fence or wall - but your options are limited to what you can do.
Robins or wrens do like to nest deep into the hedgerow so its not easy to spot until late.
What you can do then is once again rely on the plastic mesh netting to cover the length of the hedgerow - with more netting needed if necessary.
Its not a sound proof solution as an hedgerow undergrowth can be accessed, so you'd need to keep an eye on proceedings.
To finally stop birds nesting
Less intrusive, yet most friendly way to deal with birds ever using your garden to build a nest, could simply be scaring away birds throughout the day.
I no, quite a silly suggestion, but if you focus your attention only on birds who appear to be building a nest - this could deter them - so can eventually would see them vanish.
What can be more effective yet less hassle than that is to continue to pick away a nest that is only in the process of being built, come spring time.
You cannot destroy a nest or remove it from its roots to a new location, that is illegal practice in the UK.
So in taking in consideration all these ideas for how to stop birds from nesting in gardens, it can only be done before the fact.
Concentrate on stopping them accessing nesting sites in your garden by covering a tree or hedgerow with mesh netting.