This week I have been engaging in some drastic looking spring pruning. This sort of pruning applies to established shrubs that:
- Flower from mid-summer on growth they will make this season (2016)
- Will put on rapid and vigorous growth following an extreme prune
These include shrubs like hardy Fuchsia, Buddleja daviddii (butterfly bush), Spiraea japonica and Lavatera (tree mallow)
Why do we prune certain shrubs back hard in early spring?
We hard prune in spring to encourage flowering and to control the size and shape of the shrub. If left to their own devices, shrubs like Buddleja become very large, with their flowers out of sight at the top of the bush. Shrubs like Lavatera become leggy and shrubs like Spiraea become very congested.
By removing a lot of the woody frame work at the beginning of the growing season, we upset the root/shoot ratio. This leaves a large root system with more energy than the now reduced plant requires. The plant responds by sending up loads of new growth that will flower more prolifically than the older material, had it been left alone.
The process feels pretty drastic and the shrubs don't look especially ornamental afterwards, but they soon recover. It is a good idea to feed the plant with a general fertiliser following the prune. Sprinkle the granules or pellets around the base of the plant and gently work them into the ground with a hand fork
Example - Buddleja daviddii
This Buddleja is fairly young and has not been trained into a frame work. I have reduced the shoots to about 30cm above ground level
The second Buddleja has a permanent "stag horn" shaped framework. I have pruned this Buddleja back to three buds above the permanent framework. It looks a little post-apocalyptic but before long, it will re-shoot and look nice (I promise)