September Garden Tips

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  • Order Spring Bulbs now to get the best selections – many are drought tolerant. Please note that some selections such as Tulips may need additional cooling for this climate zone prior to planting.
  • Replenish mulch – hot temperatures coupled with watering speeds up the decomposition process. A to 3 inch layer of mulch (now recommended by the State of California) effectively protects plant roots against temperatures extremes, discourages weeds from germinating and conserves water.
  • Continue to clean up fallen, old and rotted fruit around citrus and other fruit trees to prevent environments for disease and pests.
  • Walnuts ripen from mid-September to October. Remove any husks and dry in shaded area with good air circulation until kernels are brittle. They are completely dry when the papery dividers between the nutmeat halves, snap rather than bend.
  • Reset irrigation clocks to adjust for changes in the weather – typically 65-70% of July’s watering. In the current drought emergency look at cutting back to 50% of the typical July watering schedule.
  • Apply pre-emergence weed control in fall. Weeds compete with ornamental plants for water and nutrients and can be sources of disease and insect infestations.
  • Fall is one of the best times to install and or divide and transplant perennials, groundcovers, shrubs and vines, especially in frost-free locales while the soil is still warm from the summer. It is best to wait until Winter for deciduous plants. Apply a weak solution of fertilizer at time of planting for best results.
  • Fall is also an excellent time to plant California native and water-thrifty trees while the soil is still warm and just before the rainy season.
  • When selecting a container tree or shrub, do not purchase if its roots are protruding out of the drainage holes, it may be a sign of being root-bound.
  • Fall fertilizing helps maintain a plant’s vigor and prepares them for the colder winter season. Apply fertilizer while soil temperatures are still warm. During this drought apply products at half strength.
  • Time to dig up and compost summer vegetables as their production declines and plant fall-winter crops.
  • Plant winter vegetables this month for establishment before the cold sets in. Plants typically stop growing when soil temperatures are at 50-55 degrees F.
  • Fall is an ideal time to aerate and rejuvenate your lawn.
  • Consider replacing annuals with perennials to fill in the spaces among shrubs and under trees.
  • Deer are more likely to visit gardens to browse in autumn as their food sources become more limited and your garden plants become more attractive. Plant deer-resistant plants like Ceanothus ‘Blue Jeans’ or Rhamnus californica ‘Mound San Bruno’. There a many deer repellants on the market – some work better than others, getting direct referrals about success stories is a good idea.
  • Raccoons may become a problem this time of year on lawns as they are training their young how to search for grubs.
  • Prune/deadhead summer flowering perennials if the seeds are not attractive to birds.
  • Continue monitoring plants for insect problems, many remain active until the real cold weather sets in
  • Consider the addition of outdoor lighting to brighten dark winter evenings. Today’s LED based fixtures are more affordable, last much longer and are less difficult to install.
  • Outdoor fireplaces and fire pits have become more popular over the last few years. Check in with your local municipality for codes and permit requirements.