Perennials are a group of plants that generally offer a long flowering season, followed by either a non-flowering season or by dormancy. They are not a low maintenance plant, because they require periodic deadheading and fertilization. Details Landscape Art installs gardens in Santa Rosa, Petaluma, Rohnert Park, Healdsburg, Windsor, San Rafael, Novato and Napa, and uses perennials judiciously.Perennials

The backbone of most gardens are the permanent shrubs, either evergreen or deciduous, which feature either colorful foliage or once yearly bloom seasons. These shrubs typically require little more than once a year winter pruning and regular fertilization. Plants that bloom for more than one year are called perennials. Herbaceous perennials include flowers and grasses, most of which die back to the ground in winter. But even though the tops are dead, the roots stay alive all winter. The plants then renew themselves the next growing season. Perennials produce season long flowers, but require deadheading when those flowers fade, followed by fertilization. Maintenance is not for everyone – some homeowners consider gardening to be an enjoyable hobby; others consider it a chore. If the homeowner is unwilling to take on the responsibility of maintaining these colorful repeat bloomers, we recommend they not be installed.

'Classic Oak' Arizona flagstone walkway meanders through a colorful summer garden

There are thousands of perennials available. Following is a list of perennials we use regularly in this climate. We like the flower color, reliability of bloom, cold hardiness, and texture.

  • Achillea (Yarrow) – there are many varieties of these yellow flowered summer bloomers
  • Agapanthus (Lily of the Nile) – grasslike clump with spikes of blue or white flowers
  • Alstroemeria – sun to part shade plant produces lots of cutting flowers
  • Astilbe (False spiraea) – good shade plant, comes in many colors
  • Bacopa – white flowered trailing spreader
  • Cerastium (Snow in summer) – silver foliage and white flowers – another spreader
  • Delphinium – upright large blue flower, often top heavy and needs staking
  • Dianthus (Carnation) – lovely low growing plant with pink, red and white blossoms
  • Dicentra (Bleeding Heart)
  • Digitalis (Foxglove) – another tall erect plant that may require staking
  • Erigeron (Santa Barbara Daisy) – one of our favorites with a profusion of mostly white daisy like flowers. Must be pruned frequently or else it becomes leggy and scraggly
  • Helleborus – lovely shade plant with large green leaves that need occasional cleaning up – available in deep red, pink, deep blue and ivory. Also comes in a green flower…one of the few green flowered plants! Reliable winter and spring bloomer
  • Lavandula ‘Provence’ (French Lavender) – lovely three to four foot plant with soft looking foliage and bluish purple flowers, which are used in sachets and dry flower arrangements. Must be deadheaded three or four times a year for continuous blooms. If not pruned, will become woody and scraggly.
  • Penstemon (Beard tongue) – reliable bloomer comes in a variety of colors
  • Salvia leucantha (Mexican Sage) – purple and white flowers on this four to five foot plant. Prune in late March after danger of frost has passed.
  • Salvia greggii – comes in salmon, pink, red and purple, salvia is semi evergreen. Prune in winter
  • Lantana – somewhat frost tender, the purple variety is the hardiest
  • Nepeta mussinii (Catmint) – profusion of blue flowers, nepeta must be cut back frequently
  • Tulbaghia violacaea ‘Silver Lace’ (Society garlic)