To Jarrah's question - I wouldn't say I was an expert and someone correct me if I'm wrong but I'd say late summer and late winter are the best times to mow to help wildlife. Obviously not ever cutting your grass too short either. Hope that helps.
Last autumn I had two swift experts come over to advise me on setting up suitable nesting sites as we have a brick barn, soon to be converted to accommodation, and I wanted to be sure I would be evicting no-one. Both seemed to think the only way to attract wildlife such as birds, bees and other good insects was to grow native weeds. However, a tour of my garden showed them sedum sepctabile heaving with insects including 4 different bees on one flower head, insects buzzing all over the echinops and late aconitums and my 5 pallet insect hotel stuffed with layers of straw, hay, pine cones, hollow canes and holey bricks and with a sedum and house leek roof garden had them speechless with wonder.
We also have trees, shrubs, log piles and an unlined pond with marginal irises and marsh marigolds and rodgersias plus lots of other nectar rich plants in the garden. You don't have to adopt the gardening equivalent of sackcloth and ashes to attract wildlife all year round. Just as well, as our soil is far too fertile for meadow wildflowers to compete with grasses.
I'm a big fan of hawthorn. It's unusual to find a hawthorn bush that does not have a bird's nest in it. The plant will be covered with blossom very soon, and covered with fruits by Autumn. You can also stack a few logs round the base to make the complete home.Pyracantha is quite similar, and just as good.In response to Jarrah's question - cutting grass to encourage flowers and insects can become a complicated subject. Basically, if the meadow has Spring-flowering flowers, then it should be cut after they have flowered and set seed. If it has Summer-flowering flowers, then it should be cut in Autumn. .Whenever the meadow is cut, it's essential to remove the cuttings. If the cuttings are allowed to rot down then they will fertilise the soil, and make it more diffcult for wildflowers to survive.
You may just have justified the continued existence of a sizeable pyracantha, which is otherwise rather annoying me - and probably the neighbours whose garden it's overhanging, out of reach of my pruning tools. Thanks, Gary.