Get a second flush of flowers
Cut back delphiniums and geraniums after the first flush of flowers to encourage a second flowering period. Feed after cutting them back.
Increase your carnations and pinks
Pinks and carnations that have become leggy, can be propagated by layering or by cuttings. Propagation can improve the look of untidy clumps.
Cut back early summer flowering shrubs
Prune (supposedly) June-flowering shrubs such as Philadelphus and Weigela after flowering. Prune deciduous magnolias if necessary.
Tidy up roses
Tie-in climbing roses and ramblers as they grow. Remove rose suckers and tree suckers.
Keep ponds clean and oxygenated
Cover ponds with nets or safety grilles in gardens where young children play. These have the extra advantage of preventing leaves falling into the pond. Clean out debris lurking in the depths of the pond. This will improve the water quality and prevent excess debris from promoting the growth of weeds, algae or marginal plantings, and from releasing toxins that could harm fish or wildlife.