It is important to put the nestbox up well before nesting season, as many birds begin their search for nest sites in February. Make sure to position your box well: ideally, fix it two to five metres high on a wall, fence, or tree trunk, where predators (including cuts and squirrels) can’t reach it.f you have a large garden you can have a mix of trees, such as maples, and most conifers, and native species. If you have a small garden with only room for one tree, consider a rowan, crab apple, small weeping birch, or native hawthorn.