more than deadheading and maybe a touch of deadleafing.
Artemisia schmidtiana ‘Nana’ and Thalictrum aquilegiifolium are just a couple of
other summer-flowering perennials that may benefit from being cut down to
basal foliage after flowering. Some grasses may develop brown leaf tips by late
summer; the cure for this is shearing or mowing them to the ground to promote
healthy new foliage. Lamium, which gets tatty in midsummer, can be cut down
to new basal foliage, and the attractive new growth will last into early winter.
Plants such as Amsonia tabernaemontana, Baptisia australis, and Euphorbia
epithymoides get not only a cut but also a style when being pruned. These perenni-
als may be formed into rounded shapes to add structure to a garden. Hedge shears
are the better tool to use for shaping perennials. Shaping plants in this way is
commonly done in public gardens where a bit more formality is in order. The
pruning done in public gardens can serve several purposes, as cuttings are
frequently taken for propagation in addition to pruning for aesthetics or regener-
ation. This is something to keep in mind in the home garden as well.
Cutting back to basal foliage after deadheading
Many summer-flowering perennials benefit from a couple of types of pruning to
look their best. First they are deadheaded down to a lateral bud, flower, or leaf,
which often means cutting them back by about a third to half; then, as new basal
foliage starts to develop and all lateral flowering (if any) is finished, the plants
should be cut back to the newly emerged basal foliage. Sometimes you will get
an additional bloom on plants pruned in this way, though the flowers tend to be
smaller and fewer than in the initial 2 flowerings. Popular perennials such as
Shasta daisy, delphinium, and ‘Moonshine’ yarrow, as well as a slew of others, fit
into this category. Remember that after cutting plants down to basal foliage
they’ll appreciate being kept moist, aerated, and perhaps topdressed with
organic matter, which is nice but not absolutely essential. In the case of heavy
feeders like delphinium, incorporating a topdressing or a light water-soluble
fertilizer after cutting back is especially helpful for healthy growth and rebloom.
In one mild year I still had a bloom (albeit only one) on my delphinium in
December, which I proudly showed to some horticultural colleagues who were
visiting for an early Christmas celebration (nothing like a little showing off!).
As always, the age of the plant and weather conditions will greatly influence
(left) Maiden pinks can be
sheared with grass shears or
hedge shears.(right) Prune sprawling stems
of Geranium endressii ‘Wargrave
Pink’ that develop after the
initial flowering.cuttinG BacK 111