Summer Maintenance

These long, hot days of summer, focus on carefully watering and fertilizing your California native garden.

The best time to plant California native plants in the semi-arid or arid Mediterranean climate of interior landscapes of Southern California is during the cool, moist fall and winter months. The cooler soil temperature will help the root systems supply the needed water to the young or transpanted plant. Water is lost through evaporation when the ground is hot and if roots are damaged during installation hot, wet soil may promote root diseases.

Here are several maintenance tasks to help you keep your garden thriving throughout the summer.

Water

  • Cut back on water as heat turns on and plants slow down.
  • Water deeply and infrequently. Make sure water is going to the root area.
  • Continue watering riparian plants.
  • Water younger plants as needed (it takes about 2-3 years for a plant to establish, plant will be 2 – 3 times the size it was when planted).
  • Excessive summer water is one of the main causes of failure with California native plants. It encourages the spread of pathogens, and results in unsustainable growth. 

Pruning

  • Deadhead to keep summer bloomers flowering (seaside daisy, California aster)
  • Right after bloom period, deadhead Ceanothus and other spring bloomers to reduce occurrence of unsightly woody stems in next season.
  • Cut back salvias by about 1/3 – 1/2 after they bloom.
  • Selective pruning of evergreen oaks, mid July – early September to avoid powdery mildew on new growth.
  • Pinch new growth to encourage fuller, denser growth habit.

Pest Control

  • Hose off plants with leaf-sucking bugs.
  • Introduce natural predators, such as lacewings and lady bugs.
  • Irrigate properly to prevent stress. 

Mulch

  • Mulch up to 3-4” deep, keeping material away from stems.
  • Consider inorganic mulch (decomposed granite, pebbles, etc.) for scrub and desert gardens. 

Resist Planting

  • Although some have luck planting all year around, summer is the least desirable time to do this. In hot, dry areas, aim to plant trees and shrubs in mid-October through February and subshrubs, perennials and vines in mid-October through April. (planting information adapted from "Care and Maintenance of Southern California Native Plants Gardens," O'Brien, Landis, Mackey, 2006, p. 53)

Plan for Fall Planting Season

  • Save the date for the Fall Planting Festival at Grow Native Nursery Claremont, the first weekend in November.