Some of the great floral displays come from the large group of plants catagorized under the catch all of spring flowering shrubs. Here you will find many genera of wonderful plants, many of which have a wide array of growth habits and blossom presentations. They have one important thing in commmon, however, and that is the way they should be pruned to achieve their highest potential flowering. With a great many shrubs, pruning during and immediately after blooming is the key to manage the plant and get the most flowers for the pruning effort. Forsythia, deutzia, philadelphus, kerria, many (but not all) viburnums, weigela, spring blooming spireas, and some species and old classes of roses fall into this catagory. There are also others not mentioned here, but they are easy to figure out by their blooming and growth habits. These shrubs produce long ascending, arching growth and then next year (after the wood ripens in fall) they go dormant in winter and they burst into spectacular bloom in spring! Their long graceful branches laden with a profusion of bloom all along their lengths. Pruning during bloom and/or immediately after blooming promotes much growth which fills in the plant during summer and then ripens in fall and at that time, flower buds are set all along that growth on those branches. What this means is that you will be getting the maximum floral effect for the pruning effort if done at this time. (*if you prune at other times, you are merely cutting off potential bloom on those pruned branches!) Thsi goes against the traditional belief (which is proper for a great many plants, but not this group!) Pruning in this fashion gives a much more graceful shrub. If growth becomes too long, simply tip it back or just pinch the growing ends of the branches. That will make the plant bushier without destroying that graceful branching effect.
You can also fertilize at this time so the plant will have additional nutrients from which to produce that profuse growth from the pruning. Do not worry about making mistakes when pruning. Mistakes are how we learn to do the best effort. Do not cut to large stubs if possible unless you are trying to renew the plant by removing some very old wood. The pruning technique is to cut last years growth back to either small side branches or strong growth buds or vigorous new shoots. Those resulting new growths will elongate into graceful branches during summer, and be lavish in bloom next spring!
Spring is also a very good time to renew a very large rhododendron, camellia, etc. by removing very old tired wood in stages over a several year period(or all at once if you do not wish to wait and can live with a stump appearance of the shrub) Lilacs are another old fashioned favorite that responds well to this pruning treatment over several years. If you are going to have to do maintenance in your garden, be like me and do as little as possible! I like zero maintenance plants and also those that only need attention once (or twice) a year! This leaves you with TIME to actually enjoy the garden instead of having to be working in it!