Tangled, woody, overgrown climbing honeysuckles can be ruthlessly cut back in the autumn and winter, as long as they are healthy and vigorous. Use loppers to reduce the plant to 60cm (24in) in height. In spring vigorous new shoots should be trained so the whole of their support structure is clad from base to top. Continually pinching out the growing tips stimulates bushy growth. Flowers are unlikely to develop until growth slows, but within a couple of years, perhaps sooner, flowering should be back to normal. Applying a general fertiliser and a mulch of rotted organic matter will help promote healthy regrowth.
If this is more extreme than the situation merits, shearing over excessive growth will be sufficient, removing most of the sideshoots. Typically, shearing back is helpful where all the growth is at the top of a wall or fence, or where a honeysuckle is too wide and spreading. Again, flowers will be slow to form, but the plant will perform more effectively when pruned.
In subsequent years heavily pruned honeysuckles that flower mid- to late summer, for example Lonicera japonica (Japanese honeysuckle), should be pruned back in spring if they need keeping within bounds. Otherwise it can be left to ramble.
Honeysuckles that flower early in the season, on short laterals from the previous year's growth, such as Lonicera periclymenum, L. x italica, L. tellmanniana and L. tragophylla, should be pruned back by about one-third in late summer immediately after flowering.