It's such a dilemma - we don't want the dandylions Roy, but we don't spray them because we want the insects and the birds. We compromise by keeping the veggi plot & garden round the house free of weeds and let the meadow run wild. Fortunately we don't have any neighbors to complain about the seeds !
I think the Hydrangeas grow pink or blue according to whether the soil is acid or lime Shelagh. Whatever, they're best in a damp climate. Ours are blue when they start to flower, but soon turn a dreary grey because the hot sun bleaches all the colour out.