Fertilizer

Question:

My fertilizer regime is minimal. I feed when they look like they need it and rarely in the summer. I apply the foliar type because it’s easier than dragging a hose around. Will I get blooms? Mary W.

Answer:

By the time orchids look like they need help, its often too late. These tropical beauties are very slow growing – taking an average of 5 years to bloom from germination. Attention to the seven basic cultural requirements - air circulation, fertilizer, humidity, light, potting medium, temperature, and water will ensure robust foliage and healthy roots. Advanced growers watch for early warning signs that the culture might be less than ideal – such as an impending change in seasons or an aging potting medium - and take immediate action.

The season that most foliar growth occurs is during the summer and fertilizer should be heaviest. Spring and fall have warm days but cool nights so only moderate nutrition is required. The sun is so low in the winter sky that plants need very little fertilizer.

Orchids take in most of their nourishment through their roots and very little through their leaves. Fertilizer programs are most effective when a powdered or liquid concentrate is mixed with the water used to hydrate the potting media. Time release pellets sprinkled on top of the potting medium can be successful but the timing of the initial application as well as selection of the proper formulation is critical. Foliar-only fertilizer will not give satisfactory results.

 

Question:

Two of my Phalaenopsis have brown scale. I am currently using insecticidal soap and rubbing alcohol on a cotton ball to clean the leaves. Any other suggestions? Joyce J.

Answer:

The leaves of Moth orchids are tender and attract a number of vicious pests. Aside from Brown Scale, other un-wanted guests could include Mealy Bugs, multiple species of Mites, and Slugs. If there are flowers present, additional party crashers such as Aphids and Thrips may arrive to dine on the delicate petals. It’s a jungle out there!

Only extreme infestations are fatal. The bugs literally ‘suck the life’ right out of the plant, leaving the foliage limp and discolored. Close examination of the greenery using a magnifying lens reveal thousands of tiny holes where the insects have been. There is usually a tell-tale ‘sticky substance’ where the juices from the plant were secreted.

Sometimes a thorough washing is advised. Taking the plant outside and hosing the leaves and roots down with water gets rid of the worst offenders. Then a regular spray program can be implemented. Most infestations are minor and can be controlled easily.

Brown Scale is challenging to control because each critter has an armored shell that protects it from common insecticides. It is best to loosen the insect from the leaf prior to spraying using a damp cotton ball and nimble fingers. Brown Scale resides under the leaves and concentrates around the outside edges of the foliage. Spraying must be thorough and cover all leaf surfaces until dripping. Insecticidal Soap or rubbing alcohol (70% Isopropyl) is effective. Weekly applications for a month are required due to the fast life cycle.

 

Question:

I vacation in South Carolina where Spanish moss hangs from the trees. I have heard that this moss, when wrapped around the base of an orchid, interferes with the orchid’s ability to breathe? Carolyn M.

Answer:

The floral industry uses Spanish moss for a wide variety of decorative purposes. Clumps of the fluffy gray stringy leaves cover the tops of unsightly plant containers and ‘soften’ the look. One might find related natural items, curly willow and raffia, in the same arrangement.

Surprisingly, Spanish moss is not a moss but rather a Bromeliad (Tillandsia usneoides)! It resides in the Southern eastern US where it clings to trees epiphytically (like orchids). Though it may find itself as top dressing for a lucky orchid and, thus, share the same air space, there is plenty of CO2 to go around. 

Date: 
Tuesday, September 1, 2009 - 17:45