January To Do List

General

• Short days and cold nights in January will keep most of your orchids in a semi-dormant growth state but Fall/Winter blooming orchids will initiate spikes at this time.  Watch them very carefully and cut back on water and fertilizer as cooler days and nights prevail.
• Protect your outdoor orchids from winter rains.  Keeping them on the dryer side will allow them to tolerate the cold winter nights we tend to experience in Southern California.  Water and fertilize sparingly during winter warm spells.
• As watering and fertilizing practices diminish for winter, be sure to leach your plants thoroughly. Make your last thorough watering a leaching process in order to address 'salt built up' issues before diminished watering starts. Roots should readily be able to absorb the little water and nutrients that they may get during this period. Roots heavily encrusted with excess minerals are not able to absorb the ones they need and may develop deficiencies or even excess toxic levels during dryer conditions.
• Keep cold-sensitive, warm growing orchids (phals, paphs, tolumnias, most vandas and warm growing dendrobiums and cattleyas such as violacea, dowiana and their hybrids) inside or in a greenhouse to protect them from night temperatures below 50°F. An excellent article on ‘Cold Tolerance of Orchids’ by Sue Bottom of the St. Augustine Orchid Society can be found in their October Newsletter (pgs. 9-11)
• Cold loving orchids, including odontoglossums, miltonias, pleurothallids, masdevallias, draculas, will thrive in cool weather and respond by initiating growth so continue to water and fertilize them during this period but also protect from freezing temps. Take this opportunity to divide or repot them during their winter growth period to encourage new growth and avoid the stress of repotting during the warm season.
• Winter blooming cattleyas and cymbidiums should be in bud or full bloom by now. Provide adequate water and fertilizer, but do so in the mornings so plants dry out before nightfall. Stake cymbidium spikes to guide inflorescences for support of buds and blooms.
• Maintain good hygiene practices to minimize transmission of pests and viruses. Watch for fungus, bacterial rot and cold burn in cold and wet weather. Remove infected tissues and treat accordingly. More information on treating these disorders can be found on the AOS website.
• More details on monthly checklist items for specific genera can be found on the AOS website

Indoors and Greenhouse

• Carefully monitor greenhouse temperatures and check that circulating fans, automatic vents, humidifiers and heaters are in good working order.
• Use a humidifier or mister to keep humidity up due to heavier use of fans and heaters in winter.  In absence of a humidifier, wet down floor to increase humidity.
• Continue to provide good air circulation for indoor plants to discourage diseases and pests such as mealy bugs and scale. Be sure to check all edges of the pot and neighboring pots. Pests, especially mealy bugs also can be found on the bottom of pots. Treat early to avoid spreading to other plants.
• Cut back on watering and frequency of fertilizing in winter. 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.

Outdoors

• Continue to monitor and control snails, slugs and other pests as cooler wet weather will bring them out. They can do considerable damage to plants in short order.
• Try not to use water that is much cooler than the plants as their tissues can be shocked. Watering early in the day will facilitate that and allow plants to dry before nightfall in order to minimize bacterial and fungal diseases.
• Most cymbidiums are now in spike or bloom so switch from high nitrogen fertilizer (30-10-10) to one with lower nitrogen relative to phosphorus and potassium (such as 20-10-20 or 18-8-17) to initiate and stimulate spike production instead of vegetative growth.  Stake spikes early to train them to grow upright while the spikes are flexible. More information is available via the AOS Cymbidium culture sheet.
• Most members of the Catasetinae family (catasetums, clowesia, cycnoches, and mormodes) are now in their dormant period as evidenced by the yellowing and loss of leaves. Note that some actually initiate spikes at the outset or during their dormant period.  Cut back and eventually eliminate water and fertilizer until Spring when new roots are established as recommended by Fred Clarke on his website.
• Most phalaenopsis are very sensitive to cold and should be inside your home or in a greenhouse by now and spiking.  Stake spikes early to train them to grow upright for optimal display of blooms.

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!