Pruning Forsythia, Weigela, Spiraea etc

Pruning Forsythia, Weigela, Philadelphus (Mock Orange), Deutzia, Buddleja alternifolia, Berberis (deciduous types), Exochorda (The Bride), Kolkwitzia, Ribes, Tamarix (Spring flowering type), Spiraea -spring/early summer flowering types.

For this group (Early blooming, on last year's wood) do your pruning immediately after flowering.

This is probably the most misunderstood aspect of pruning. Shrubs which flower early in the year, on stems that they produced the previous year. If the shrubs are not pruned right after flowering, then there will not be enough time left for the shrub to produce growth before the autumn - when growth ceases - or for it to produce the flower buds upon that growth. Many of these shrubs will initiate next year's flower buds in June or July of this year. If you delay pruning too long, then there will be no stem growth for the plant to put its flower buds on!

a/ Cut back flowered growths at least 1/3rd of the way back into the shrub, to a new young shoot; or a strong bud (Leaf joint)

b/ Cut some of the growth - about 25% - right back to within a few cm of the ground. This will produce nice basal growth, which in turn will be part of your framework for the following year. If you don't do this, then the shrub will simply get taller each year, with the flowering growth right at the top.

Pruning cuts well back into the growth.

Don't forget the lower cuts to force some basal growth.

This picture shows 5-6 'basal' cuts, which
will encourage new growth from the base.

Spiraeas - late spring and summer flowering

Here a Spiraea Snowmound - just finished flowering (Late June). Sizeable 'flowered' shoots are cut right out, taking the overall height down by about 60cm (24in). It will regain this height again during the next few months, with plenty of flowering growth ready for next year. Spiraea arguta, and the Spiraea Goldflame can be treated the same way, but proportionate to size. (If desired, they can be cut right back to within a few cm of the ground! In any event it is good to cut a few of the branches off close to the ground to promote basal shoots - see above.)