Pruning Siberian bugloss 'Looking Glass'
When and how — Brunnera macrophylla 'Looking Glass'
Prune your siberian bugloss 'Looking Glass' in March and November — the optimal month is usually November.
The next pruning window is November.
When to prune?
The perennial siberian bugloss 'Looking Glass' is pruned in March and November.
With perennials, pruning is really seasonal management.
You don't prune perennials the way you prune shrubs. The work happens at three moments: (1) deadheading spent flower stems during the season to encourage repeat bloom, (2) optionally cutting back to about 10–15 cm above ground in late autumn, and (3) clearing all the old foliage in March before the new shoots emerge. Many gardeners now deliberately leave the old growth standing through winter — it protects the crown and shelters overwintering insects. Which approach to choose depends on taste and species: evergreen perennials (hellebore, bergenia) look better left alone, while wet-rotting species (hosta) need to come down after the first frost.
How to prune siberian bugloss 'Looking Glass'
Brunnera macrophylla 'Looking Glass' requires very little pruning, but some tidying keeps it looking its best and prevents self-seeding if that's a concern. The main pruning windows are March and November, though light maintenance can be done throughout the growing season. In late spring and summer, remove any foliage that becomes scorched, tatty, or mildewed—this is most common if the plant is in too much sun or the soil dries out. Simply cut damaged leaves back to the base with clean secateurs or snip them off by hand. This encourages fresh growth and improves air circulation, which helps reduce fungal issues. After flowering finishes in late spring, you can deadhead the spent flower stems if you prefer a tidier appearance or want to prevent self-seeding. Cut the stems back to just above the foliage mound. However, the tiny blue forget-me-not flowers are fairly inconspicuous once faded, so many gardeners leave them. The main pruning session is in November or early March. In autumn, once the foliage has been hit by hard frosts and starts to collapse, cut back all the old leaves to ground level. Alternatively, leave this job until early spring before new growth emerges. Either timing works well; autumn tidying reduces slug hiding places over winter, while spring pruning provides some frost protection for the crown. Use clean, sharp secateurs and remove all the previous season's foliage. Fresh, silvery leaves will emerge in spring. Brunnera doesn't require any shaping or structural pruning—just this annual clear-out.
Common mistakes
✗ Cutting back too early in spring
Late frost can still strike and the old foliage protects the crown. Wait until the first new shoots are visible (usually mid-March) — then you know the season has actually started.
✗ Skipping deadheading
Hardy geranium, salvia, lupin and delphinium will give a second flush if you cut spent stems back to just above a pair of healthy leaves as soon as the first flowers fade.
✗ Cutting ornamental grasses down in autumn
The dry stems are the whole point of winter interest, AND they protect the crown from frost and waterlogging. Cut down to a fist's height only in late February.
Combine with feeding
In March you can combine pruning with feeding — efficient, and you only disturb the plant once. Read the full care guide for siberian bugloss 'Looking Glass' →
Hold off on pruning
Better to wait than prune at the wrong moment. The next optimal window is November. Until then: leave the plant alone — only remove dead or diseased wood (which you can do year-round).
