July To Do List


  • Avoid excessively high summer light levels and temperatures this month by providing sufficient shade, increased air movement, and watering/misting to cool plants and prevent them from drying out.  This is particularly important for individuals who live and grow in inland areas.  
  • Although cattleyas, dendrobiums and cymbidiums thrive in high light levels, phalaenopisis, paphiopedilums, miltonopsis, masdevalias and other lower light plants can easily burn.  They also are readily stressed by high temperatures so try to move them in cooler areas of your growing structures.  For most orchids, one wants to have light grassy green leaves.  Dark green leaves suggest too little light, while yellow colored or red tinted leaves usually indicate too much light.
  • July continues the growth and repotting for some orchids (cattleyas, oncidiums, dendrobiums) as new roots continue to emerge from pseudobulbs or fans. Try to repot when roots are small and just beginning to show in order to minimize damage to soft tissues and avoid transplant shock, giving plants a head start in the growing season.
  • Repot when orchids have begun to over grow their pots and/or when media has started to break down.  Also consider repotting plants that have been in pots for 2 or more years and are existing, but not thriving. Repotting can revitalize and provide new vigor to such plants.
  • As you repot and divide many of your plants, set aside the extra divisions as donations for the POS auction or for silent auction at the meetings. It will prevent overcrowding of your benches and make someone else happy to get a piece of your prized plant.
  • Continue to follow good hygiene practices to minimize transmission of pests and viruses, particularly during the warm summer months when pests and diseases can proliferate very quickly and spread throughout the collection. Carefully inspect plants for scale and aphids and treat early to minimize spread.
  • More details on specific genera can be found on the AOS website

Indoors and Greenhouse

  • Address higher light levels by adding shade cloth or painting with shading compound to avoid burning sensitive plants. 
  • Carefully monitor greenhouse temperatures as higher summer temperatures can easily cook plants. Make sure fans and automatic vents are in good working order. Mist plants to increase humidity and cool down temperatures.
  • Continue to provide good air circulation for indoor plants to discourage diseases and pests such as mealy bugs and scale. Treat early to avoid spreading to other plants. More info on pests and diseases can be found at the AOS website.
  • Increase watering and fertilizer to accommodate growth during this period. Avoid over fertilizing to minimize root damage and growth of soft growths. Keep to one half to one fourth the recommended amount on the package.


  • Continue to monitor and control snails, slugs and pests during warm weather. They can do considerable damage to plants in short order.
  • Cattleyas, oncidiums, and summer blooming cymbidiums should in full bloom and/or producing new root and bulb growth as well as hardening off of growth produced in the spring.  Increase watering frequency and fertilizer as new growth is observed and repot as appropriate. Stake oncidiums to support flower spikes.
  • Catasetums should be growing rapidly now.  Continue to give them warm temperatures, high light and fertilize well at each watering to take full advantage of the growing season.  You will be rewarded by rapid growth all summer, followed by beautiful blooms in the fall and winter. More details on culture can be found on Fred Clarke’s website


The monthly To Do list is a collaboration of several POS members. We appreciate any and all comments, suggestions, and feedback on our new feature. Please send them to newsletter@palomarorchid.org!