Pruning Your Native Plants
Pruning can add considerably to the beauty of a landscape. As plants grow, it may be necessary to restrict their height or spread, though whenever possible, this can be avoided by choosing the right species originally. A plant may have branches that have to be removed because they are overlapping or growing lop-sided. Some plants, such as the Elderberry, can be trained as either tall shrubs or small trees. One can prune to open the center to reduce fire danger, or to display branch structure as with the Manzanita.
In general, it is best to shape plants by pinching tips whilst they are young. Deciduous plants are usually pruned in their dormant season, though summer pruning can be helpful in controlling growth. With many evergreens, especially conifers, pruning should be done gradually and only where necessary. Many plants should be pruned after flowering, both to dead-head and to train the growth spurt which often occurs at this time. Some perennials, from grasses to Wooly Blue Curls, will profit from being cut to the ground, and even some woody shrubs will re-sprout from the crown, to ‘start again’, if such a radical approach is desirable.
Brown G.E. & T. Kirkham 2004: The Pruning of Trees, Shrubs and Conifers. One of the standard works.
O’Brien B. et al. 2006: Care and Maintenance of Southern California Native Plant Gardens.(in English and Spanish) There is a brief overview of techniques, and in addition advice on the pruning of individual native species.