All form plants must be cut at least once a year to ensure they maintain the intended shape. The annual drive is regularly cut back so that the surface of the plant will get ever more dense with time and the shape gets perfect. In general, the whole shoot is never pruned. Thus, despite frequent cutting, the plants put on more and more in size. If the timming is not done for year or two, a strong pruning is necessary to preserve the original shape.
Young plants that have not yet reached their final form, need a second cut per year. They should be pruned the first time in May and trimmed a second time about six weeks later in July. Older plants should be cut only once, the best time is from late May to late June. After then boxwood should not be cut, so that the new shoots are mature until winter and have thus developed enough to withstand frost.
The cutting gets easier with the years, as the surface becomes denser and therefore stronger. The danger to make a mistake while trimming decreases. Only cut during cloudy overcast days, otherwise the leaves that are exposed after the cut could easily burned.
The most important device for cutting of form trees is the hedge trimmer. You can work much more accurately when cutting fine curves or exact geometric shapes than with electric cutters. Look for good quality. Regularily rub the cutting blades with vegetable oil to prevent them from getting clogged with resinous leaf material.
Small forms and spheres can be cut well with scissors, which are otherwise used for cutting lawn edges - but what is quite tiring with prolonged use.
From trees do not need special or particularily strong fertilization. After pruning you supply the plant with slow-release fertilizers. That's enough to supply lasting nutrients.