A sharp lesson from 'Tracy Scissorhands' Why prune perennials? Stephen Lacey asks the woman who knows - and is converted

• Published in: Daily telegraph (London, England : 1969)
• Main Author: Lacey, Stephen
• Format: Newspaper Article
• Language: English
• Published: London (UK) Daily Telegraph 09.04.2005
• Subjects: DiSabato-Aust, Tracy; Scissorhands, Tracy
• ISSN: 0307-1235

Pruning can also delay the flowering by a week or so -- handy if you are planning a party or going away and don't want to miss the display. If plants are pruned nearer to their natural flowering time (in which case they should only be tamed by 12cm at most), the delay is often doubled. Autumn-flowering perennials are rarely delayed. Pruning anything much after the end of June tends to produce no flowers at all. Cutting back perennials in early summer before they have bloomed is not entirely unheard of in Britain; we call it the ``Chelsea Chop'' because it is usually carried out in Chelsea Flower Show week. It is used successfully, for example, on Campanula lactiflora at the Garden House, Devon. By cutting back the clumps to different heights and leaving some unpruned, a longer and more varied display is achieved. But no one in this country has researched the subject as comprehensively as [Tracy DiSabato-Aust], or advocated its use so widely. Her principles have been taken up with gusto at the Oxford Botanic Garden, where a curving double border, designed by Nori Pope, is programmed to bloom from August to November. Curator Louise Allen tells me that pruning is used both to shape autumn performers, such as Aster laevis `Calliope' (different parts of the clumps being cut back over a period of three weeks) and to retard summer- flowering species. Nepeta `Six Hills Giant' is shaved in full flush in late June, encouraging it to bounce back with attractive foliage and flowers, as are the flowering stems of cardoons.