Orchids as House Plants

Phil Mullarky mullarkyp@gmail.com

Orchids as House Plants

Phil Mullarky mullarkyp@gmail.com

What is an orchid?

Terrestrial

In Trees

On Rocks

Where do Orchids Grow?

An orchid is a member of the Orchidaceae family, the largest

group of all living flowers. There are at least 25,000 different

species of orchids

The orchid flower, like most flowers of monocots, has two

whorls of sterile elements. The outer whorl has three sepals

and the inner whorl has three petals.

Terrestrial Orchid – Growing in

Soil Lady Slipper orchid. Cypripedium candidum. Minnesota

Epiphytic Orchid – Tree Loving

Cattleya forbesii

Notice how roots are clinging to the tree

Rock Loving

Liparis bracteata

Notice the lichen and leaf litter surrounding the plant

Lithophytic orchid

Potted Cattleya

• Slc. Jewel Box ‘Dark Waters’

• Note papery material on

pseudobulbs

So what do we do? We jam them in a clay pot

Orchid mounted on cork slab

Note: There is sphagnum moss between the cork

and orchid. This aides in retaining moisture.

Wood Basket

The plant has no potting material in the

basket

Creating a humid environment

Pebble and Humidity Trays, Wardian Case

• Pot must not rest in water, but on the pebbles

• Pebbles and tray should be cleaned to prevent algae, fungi etc.

Orchid Kiekie • Kiekie is Hawaiian for baby (“the little one”)

• Kiekie paste – cytokinin hormone, induces

growth at node.

• Notice potting material – sphagnum moss

Where to cut the inflorescence • Notice the nodes.

• Cut at, or below first node. Use sterile blade.

• Cutting above the second node will encourage

branching.

Arial Roots

Root is covered with white spongy material -

Velamen

You can’t contain them! You can’t contain them

Old vs. New Potting material • Ad from Orchidata on their potting

mix.

• Notice difference in root vigor.

Flower spike (Inflorescence)

Typical Orchids for Home Culture

Phalaenopsis

Phalaenopsis type

Dendrobiums

Cultural Requirements

Light

Temperature

Water

Air Movement

Fertilizer

Potting Mix

Light

Sufficient light is important for healthy growth and

flower production.

In the home, an east, west or lightly shaded south

window. Under lights, four 40 watt fluorescent

tubes and two 40 watt incandescent bulbs directly

over plants.

Too much light – leaves start to turn yellow

Temperature

Phalaenopsis

Mature plants need a 15 to 20 F difference between

night and day.

PROVIDE Nights of 60 to 65 F; days of 75 to 85 F.

Dendrobium

Mature plants need a 15 to 20 F difference between

night and day.

PROVIDE Nights of 60 to 65 F; days of 80 to 90 F.

Water

Phalaenopsis

Mature plants should seldom dry out between

watering's.

Dendrobiums

Keep evenly moist while in active growth. Allow to

dry between watering after growth is mature

(indicated by terminal leaf).

Air Movement

Circulating fans

Ceiling fans

Computer fans

Fertilizer

Orchids need to be fed regularly.

Growers suggest using a "balanced" fertilizer such as 20-20-20 that includes

all "necessary trace elements."

Regardless of the fertilizer formulation you choose to use, it should contain

little or no urea. If you are unsure of what fertilizer to use, you can generally

use any fertilizer you would for your other container plants.

Orchids will do far better with too little fertilizer than with too much.

Many growers recommend the "weakly, weekly" approach, applying a dilute

(1/4 strength) fertilizer each time they water, rather than applying a full dose

once a month.

It’s best not to fertilize a completely dry plant as the fertilizer can burn the dry

roots. Water first then follow with fertilizer solution.

Fertilizers Nutrients Needs

Orchids need 16 nutrients - nine macronutrients and seven micronutrients. Macronutrients are so called because they are needed in larger quantity. On the other hand, micronutrients, though equally critical to the health of orchid, are need in very small amount.

Macronutrients needed Hydrogen (H) – food production

Carbon (C) – food production

Oxygen (O) – food production

Nitrogen (N) – leave and stem growth

Phosphorus (P) – flower production

Potassium (K) – general good health and orchid issue building

Calcium (Ca) – cell wall formation and cell activity regulation

Sulfur (S) – combined with nitrogen and phosphorus to produce proteins

Magnesium (Mg) – part of chlorophyll molecule and thus for producing food

Micronutrients – catalysts in vital chemical reactions Iron (Fe)

Manganese (Mn)

Zinc (Zn)

Copper (Cu)

Boron (B)

Molybdenum (Mo)

Chlorine (Cl)

Fertilizers

Recommended Fertilizers

Jack’s Classic (Original Peter’s) 20-20-20 (Chelated)

Grow More – All Season’s Plant Food 20-20-20 (Chelated)

Dyna Gro 7-9-5 (Not Chelated)

Miracle Gro 20-20-20 (No micronutrients)

MSU RO Water Special 13-5-15 (½ - 1 teaspoon per gallon)

Source: http://theorchidhouse.org/shop/msu-orchid-fertilizer-ro/

Potting Mix

A selection of orchid potting media.

Clockwise from one-o-clock: tree fern, lava rock,

Aliflor, sphagnum moss, osmunda, rockwool and fir

bark in the center.

Scale

• Rubbing alcohol

• Insecticidal soap, Neem

Oil

• Orthene, Malathion,

Diazinon

Where scale hides

• Picture on left shows cattleya with old

sheath

• Sheath removed on right.

Mealybugs

Treatment is the same as for scale

Black Rot Caused by fungus - Pythium ultimum and

Phytophthora cactorum

Treatment – Cinnamon, Truban

Botrytis Caused by the fungus Botrytis. Damp conditions, poor

air movement

Only effects flowers.

No useful treatment. Sanitation

Blc. Ronald’s Canyon ‘Koko Head’

Eria confusa

Phal. No Complaints

Brs. Spider’s Gold x Brs. Boedeker ‘Super

Witch Doctor’

Asc. miniatum

Wils. Red Pacific ‘Deep Shadows’

Dracula vampira

Dracula bella

Dracula chestertonii

Good Web Sites

American Orchid Society

https://aos.org/Default.aspx?id=38

Orchid Pests and Diseases

http://www.staugorchidsociety.org/culturepests.htm

Thank You…

Happy Growing!