The Well-Tended Perennial Garden The Essential Guide to Planting and Pruning Techniques, Third Edition

used for height control where shorter

plants are desirable. Cutting back by

half in early June when plants are 2 ft.

tall can produce 4 1/2- to 5-ft.-tall plants,

rather than the typical 7-ft. height.

Flowering may be delayed by a week or

so. A few stems still may fall over at

this height, but staking is not required.

Cut any fallen stems down to the basal

foliage before winter and leave the rest.

Usually all stems will fall over some-
time in the winter, but they are still
enjoyed by the birds. If this untidy
winter habit is not tolerable, cut all
stems down late in the autumn,
leaving the basal growth.
other maintenance Trouble-free
plants except for light staking or
pruning to handle massive height.
Three or 4 sturdy stakes can be placed
around the perimeter of the foliage in
the early summer with twine tied from

stake to stake as light support for any

wayward stems. Divide every 4–5 years

in the spring or early autumn.

related plantS Rudbeckia nitida

‘Goldquelle’ has large double flowers

that need deadheading or else they

look horrendous. Deadheading can

also prolong bloom. May need staking

in rich soil.

Ruta graveolens

common rue

r utaceae

Blue-green aromatic foliage; small yellow

flowers

1–3 ft. high; 2 ft. wide

Full sun

Blooms July–August

Zones 4–9

pruning Common rue is actually a

woody subshrub that may need to be

Rudbeckia nitida ‘Herbstsonne’