Curb the often-leggy habit of these perennials by pinching back the stems when growth takes off in spring. You'll be rewarded with compact growth and heavier flowering.

• Artemisia spp.(Artemisias)
•  Aster spp. (Asters)
• Boltobiaasteroids  (Boltonia)
• Chelone lyonii  (Pink Turtlehead)
• Chrysanthemum spp.  (Chrysanthemums)
• Helianthus spp. (Sunflowers)
• Lobelia spp. (Lobelias)
• Lychnis spp. (Campions)
• Monarda didyma (Bee Balm)
• Phlox paniculata (Garden Phlox)
• Physotegia virginiana (Obedient Plant)
• Salvia spp. (Sages)
• Sedum spp.(Sedums) 

PERENNIALS TO DEADHEAD         

• Perennials To Snip
  Remove individual spent flowers from the following plants to encourage rebloom, longer bloom, or better overall appearance. Cut just above a leaf node to remove spent flowers. New flowers will grow from the leaf axils at the node.

 For Rebloom:

• Achillea (Yarrow)
• Alchemilla  (Lady's Mantle)
• Campanula lactiflora (Milky Bellflower)
• Centaurea montana  (Perennial Bachelor's Button)
• Centranthus ruber  (Red valerian)
• Delphinium
• Gypsophila  (Baby's Breath)
• Lobelia siphilitica and hybrids (Lobelia)
• Lysimachia clethroides  (Gooseneck Loosestrife)
• Matricaria  (Feverfew)
• Phlox  paniculata  (Garden Phlox) [Except 'Bright Eyes', which reblooms from the spent flower heads]
• Salvia x superba  'East Fresland'   (Sage)
• Tiarella  (Foamflower)
  

Continuous Bloom:

• Erysimum; syn. Cheiranthus  (Wallflower)
• Helianthus  (Sunflower)
• Knautia macedonica  (Knautia)
• Lychnis coronaria  (Campion)
• Platycodon  (Balloon Flower)

To Improve Overall Appearance:

• Ajuga  (Bugleweed)
• Aruncus  (Goat's Beard) [Wait until bloom browns out and weighs down foliage]
• Astilbe  (False Spirea) [When it becomes unattractive]
• Bergenia  (Bergenia)
• Echinacea purpurea  (Purple Coneflower)
• Echinops (Globe Thistle) [Deadheading will avoid seeding throughout the garden]
• Geranium macrorrhizum (Bigroot Geranium)
• Helleborus (Hellebore) [Wait until after seed sets]
• Hemerocallis (Dayliliy)
• Heuchera (Coral Bells)
• Hibiscus moscheutos  (Swamp hibiscus)
• Hosta
• Paeonia (Peony)
• Phlox divaricata (Woodland Phlox)
• Stachys  (Lamb's Ear)

  PERENNIALS TO SHAPE

  Shape the following plants that bloom in a single flush by clipping them back by about one-third into a rounded form after they have bloomed.

• Amsonia  (Bluestar)
• Ballota
• Baptisia  (Blue False Indigo)
• Euphorbia polychroma; epithymoides  (Cushion Spurge)
• Marrubium  (Horehound)
• Oenothera fruticosa; tetragona ssp.glauca (Sundrops)

  PERENNIALS TO SHEAR

  Cut the following plants down to the ground after they have bloomed. This will stimulate lush new foliage and possible rebloom. Mulch to protect the plants from the summer heat and give them plenty of water.

• * Alchemilla  (Lady's Mantle)
• Brunnera
• * Geranium endressii, G. platypetalum  and hybrids
• * Nepeta  (Catmint)
• * Pulmonaria (Lungwort)

      * Only if necessary, otherwise snip or shape as appropriate.

PERENNIALS NOT TO DEADHEAD

 Allow the seed heads of these plants to remain for winter interest.

• Anemone x hybrida  (Japanese Anemone)
• Caryopteris  (Blue Mist)
• Cimicifuga  (Snakeroot)
• Kalimeris pinnatifida  (Orphanage Plant)
• Perovskia  (Russian Sage)
• Rudbeckia  (Black-Eyed Susan)
• Sedum
• Ornamental Grasses