*Disclaimer: All information provided on this website is for general informational purposes only and should not be considered professional advice. The Aiea Orchid Club and its members assume no liability for how the information is used or actions and decisions based on the content.

Culture

Orchids are one of the easiest families of plants to grow. If you follow a few basic rules, you can become successful in a very rewarding hobby.

Lighting and Shade

Ideal lighting for maximum growth is full-day filtered sunlight (away from buildings or trees). Certain species may require more or less shade. In general, seedlings benefit from more shade. Use of a 60% shade cloth is common.

Temperature and Humidity

In Hawaiʻi, we are blessed with near-ideal temperatures for many tropical orchids (low 60s to high 80s). Especially in the summer, we need to avoid heat stress. To do this, consider misting. The evaporation will cool the orchids and increase humidity. Good air circulation will also keep the orchids cool.

Watering

Watering orchids is often misunderstood. It is imperative to avoid overwatering. Orchid roots need air as much as they need water. Most orchids do well if the media is allowed to dry slightly between watering.

Watering rule: when in doubt, don’t water. After all, when was the last time you killed an orchid by underwatering? When you do water, water heavily to flush the media of accumulated salts.

Air Circulation

Most orchids are epiphytes (plants that grow on trees) & do not like stagnant air. Good air circulation may help to reduce fungal and insect problems. Avoid overcrowding. Remove vegetation around and below your growing areas.

Proper Cultural Practices and Pesticide Use

Good culture conditions may reduce your need for pesticides.

Always refer to the instruction & safety label on any products you use

• Remove all dead and diseased plant materials. They can be a source of infection.

• Control weeds and pests in and around your growing area. Weeds and other plants often harbor insects (thrips, for example, love highly scented flowers such as gardenia and pikake).

• Monitor your orchids closely and take care of problems as they occur. Spot spraying may be all that is needed to rectify the problem. When using pesticides, always wear protective clothing and always follow label directions.

• There are many ready-to-use ‘soap’ products on the market today that offer safer options vs. pesticides.

*Home Remedies - Alternative/Options to Insecticides for thrips, spider mites, scales, and white flies:

• Water is a mechanical insecticide; it can dislodge insects from your orchids. Spray in all directions to bathe your orchids.

• Ultrapure horticultural oil. Best sprayed in cool evening.

• 70% alchol spray — use it very early in the morning or even in the evening when it’s cool out.

• Home Pesticide Recipe:

  • mix together and spray:

  • 2-1/2 tablespoons vegetable oil

  • 2-1/2 tablespoons detergent or hand soap

  • 1 gallon water

• Boric Acid mix for ants:

  • 3 cups of water

  • 1 cup of sugar

  • 3 teaspoons of Boric Acid

  • Mix to dissolve. Saturate a small piece of cotton with the solution & poke it into the middle section of a wide plastic straw about 3 inches long. Place or tape a straw horizontally in the path of or near ants. Keep away from pets and children. Straw protects rain/water from dissolving the solution. Ants will carry bait to their nest over several days & eventually it will kill the nest. Works well for black ants, ghost ants, or ones that feed on nectar or sugars

*Fungicides

Always refer to the instruction & safety label on any products you use. The label is the law. Fungicides may not be necessary if culture considerations (air, light, water) are adequate.

• Cinnamon is a naturally occurring minor fungicide. The effectiveness varies by the quality of the cinnamon (age of cinnamon, amount of bark in the product). You may apply cinnamon directly to the plant wound by dusting the affected part or apply a paste of cinnamon mixed with water. Cinnamon powder is dehydrating so it will act to dry out the infected area, which is the first step to get rid of fungus. Fungi do not like dry conditions.  You may apply cinnamon to the roots.‍ ‍

• Avoid copper-based fungicides (such as Kocide, etc.) on Dendrobiums.

• These fungicides are all restricted for use in home edible gardens so be sure to read and follow all label directions. They may be toxic to animals, fish and aquatic life, so consider run off if using near ponds etc. The label is the law.

  • Dithane M-45 — a broad-spectrum contact fungicide used for ornamentals.

  • Heritage (Active: Azoxystrobin)

  • Pageant (Active: Pyraclostrobin & Boscalid)

  • Physan 20 (Active Quaternary Ammonium)  

  • Thiomyl (Active: Thiophanate-methyl)

*Fertilizing

Always refer to the instruction & safety label on any products you use. Strength and frequency of use differ between products.

• Water-soluble Fertilizers

  • 30-10-10 high nitrogen boost for vegetative growth

  • 10-30-20 or 5-15-17 for blossom booster

  • 18-18-18 or 20-20-20 are balanced general-purpose fertilizers.

• Granular or Time Release

  • Gaviota Anthurium & Orchid Fertilizer

  • Nutricote 13-13-13; 18-6-8; etc.

Repotting

Most, but not all, orchids should be repotted every 2 years or when they outgrow their pot. Timing is critical for some types; repot during the growing season or when new roots emerge.

Instructions for taking plants out of community pots:

Wear gloves when handling chemicals

Soak plants for about 5 minutes in:

• Physan 20 — 1/2 tsp. per gallon for preventive dip.

  • (Physan 20 is a fungicide used for fungus, virus, bacteria, mildew, algae, and also for cleaning tools)

• Vitamin B-1 (Thiamine) — 1/2 tsp. per gallon

  • Thiamine reduces transplant shock and primes the immune system against disease. It supports the overall health of the plant but is not a growth hormone.

Sanitation

In order to reduce the spread of viruses/diseases, these tasks should be done before the orchids are handled or transplanted.

• Flame or sterilize shears & tools before use between each plant

• Wear gloves or wash your hands with soap and water before handling each plant

• Work on newspaper and discard top layer after each plant.

Potting Mix — Types of Media

It is best for each person to experiment with different media to determine what works best for the plant type, location, and cultural conditions. In general, the bark size used is aligned with the pot size. Big pot, big bark; small pot, small bark. Pot size is determined by the amount of roots; roots should touch the sides of the pot. The type of media & other conditions will determine frequency for watering.

• Option A

  • 3 parts fir bark (medium for bigger plants and fine for 2” pots)

  • 1-1/2 parts peat moss

  • 2 parts coarse #3 pearlite

• Option B

  • #3 Blue Rock — excellent media for those who live in a high rainfall area. Also good for tall plants in windy areas prone to toppling.

• Option C

  • Hapuʻu (Tree Fern) Fibers — excellent stability, longest-lasting organic media, excellent growth.

• Option D

  • New Zealand Sphagnum Moss — Excellent media to establish a young plant or to revive an old plant. Sphagnum moss had natural antibacterial and anteseptic properties.