Orchids of Los Osos Growing Tips

Miltonia and Miltoniopsis

Light & Shade
Miltoniopsis require a rather low amount of light (1,500-2,000 footcandles). If grown in the home, east or west exposure is recommended. A southern exposure can be tolerated if shielded from the sun.

Temperature
Miltoniopsis should do well in the average home or intermediate greenhouse. A night temperature of 58-64 F. and a daytime temperature of 70-80 F. is considered best. They will tolerate higher or lower temperatures, but not for extended periods.

Humidity
If you keep your Miltoniopsis well watered, humidity is not a critical factor. However, try to keep humidity above 50%.

Watering
Miltoniopsis like to be kept fairly moist with a slight drying between watering. Frequency of watering is affected by pot size and air flow: during warm dry weather this may be 2-3 times a week, during cool weather 1-2 times a week depending upon pot size and air flow. A sure sign of under watering would be the formation of accordion-pleated leaves. If this happens, increase watering slightly.

Feeding
Prior to fertilizing, water plant with clear tepid water. Dyna-Gro is the ideal brand to use as it provides all six of the macro nutrients and all essential trace minerals plants need to be healthy, grow and flower. Mix 1/2 tsp. of Dyna-Gro Grow with one gallon of water and use with every watering. To assist blooming, switch to the low nitrogen/high phosphorus Dyna-Gro Bloom formula or Mag-Pro supplement for the winter and/or pre-bloom periods.

Potting
Miltoniopsis do well in a mix of medium coconut chips, charcoal and coarse spongerock. It is important that the pot drain well. Miltoniopsis like to be somewhat potbound so allow for only one year's growth. Repot each year in the spring.

Odontoglossum, Oncidium, Brassia

The oncidium family is very large and includes many different varieties. This instruction sheet deals with oncidium types that have thin leaves, pseudobulbs and branching sprays with flowers colored in yellow and mahogany.

Watering
Water when the mix just approaches dryness in large pots 6 inches or larger. You can check the mix for moisture by sticking a wooden pencil into the mix about 3-4 inches. When you pull the pencil out, check the wooden end. If it has turned dark in color, the mix is still wet and you should wait a day or two.

Light
Grow in bright diffused light; east or west windows are ideal. South windows will work but one should be careful of the brilliant sun that will come in during the fall through spring months. If you have miniblinds or sheer curtains, you can break the light so that it is more diffused.

Temperature
Ideal night temperatures (fall, winter and spring months) are 60-64 F. Ideal daytime temperatures are 70-85 F.

Humidity
Humidity levels for these plants should be kept at 40% or above.

Flowering
Depending on the variety, the flowering season can be at any time of year, but it is generally heaviest in the fall and spring. Many hybrids can bloom 2-3 times per year. In order to initiate the flower spikes, it is important to grow the plant in an area where the night temperatures fall below 65 F. Usually plants growing by a window are a couple of degrees cooler than the rest of the house.

Repotting
Repot every year as the mix breaks down or the plant outgrows the pot. Carefully pull plant out of the pot. Clean off the roots of the old mix, being careful not to break the good roots. Roots which are bad and should be cut off are those that are brown and mushy or papery. Those roots which are white or tan and are firm to the touch should be left alone. Place the plant into a new pot positioning the oldest growth towards the back so there is room for the newer growth to develop for about a year.

Dividing
Oncidiums can be divided when there are 6 or more pseudobulbs. Divide, leaving 3 growths per each division.

Paphiopedilums

Paphiopedilums, or slipper orchids to some, originate from the jungles of Southeast Asia and Indonesia. They are semi-terrestrial, growing in humus and other material on the forest floor, on cliffs in pockets, and occasionally in trees. They're easy to grow in the home, under lights, or in the greenhouse.

Light
"Paphs", as we call them, like shady conditions, as in the home in an east or west window, or near a shaded south window. In the greenhouse, heavy shade must be provided - giving them about 1000 to 1500 foot candles. Fluorescent light is excellent; use 2 or 4 tubes just over the leaves.

Water
Since they have no pseudobulbs and store most of their water in their leaves, paphs must have water constantly available at the roots. They need a moist medium - never soggy, but never dry. Water once or twice a week. Humidity should be moderate, between 20% and 30%, which can be maintained in the home by setting the plants on trays of gravel, partially filled with water, so that the plants never sit in water. In dry climates, misting (in the morning only) can help increase humidity. In a greenhouse, average humidity is sufficient; spraying the floor or using an evaporative cooling system in warm climates can increase the humidity. Air movement is essential, especially when humidity is high.

Temperatures
Many growers separate paphs into two groups, the warm-growing mottled-leaf types and the cool-growing, green-leaf types. Warm-growing types should be 60-65 F at night, and 75-85 F or more during the day. Cool-growing types should be 50-60 F at night, 75-80 F during the day. All plants may be grown in the same temperature range with excellent success. The plants can stand night temperatures in the 40s if necessary (as when grown outside in mild climates), as well as temperatures to 95 F. Care must be taken to protect the plants from rot when cold (keep humidity Iow, and do not let water stand on leaves or in the crowns of the plants), and also to protect from burning when hot (shade more heavily and increase humidity and air movement).

Fertilizer
High-nitrogen fertilizers (20-20-20) are recommended when potted in any fir bark mix. In warm weather, some growers use full-strength applications every two weeks; others use strength every watering. It's important to flush with clear water monthly to leach excess fertilizer, which can bum roots. In cool weather, fertilizer applications once a month are sufficient.

Potting
Paphs should be re-potted about every two years, or as the medium decomposes. Seedlings are often repotted annually. Mixes vary tremendously; most are fine- and/or medium-grade fir bark, with varying additives - perlite (sponge-rock), coarse sand, sphagnum peat moss, etc. Moisture retention with excellent drainage is needed. Divide large plants, by pulling or cutting the fans of the leaves apart, into clumps of 3 - 5 growths. Smaller divisions will grow, but may not bloom as well. Spread the roots over a small amount of medium in the bottom of the pot and fill with medium, so that the junction of roots and stem is buried «" deep in the center of the pot. Do not overpot; an average plant should have a 4" - 6" pot.

Phragmiprdiums

Phragmipediums are new-world ladyslippers that grow from Mexico through the central and northern parts of South America. They can be found growing on rock outcroppings (Mexipedium xerophyticum), in forks of trees (caudatum), or volcanic clay (boisserianum or wallisii). Some plants such as longifolium, ecuadorense, pearcei or klotscheyanum grow submerged underwater through periods of heavy rainfall. The flowering season is heaviest in the spring, but many species can be in bloom for 6-11 months at a time. The flower colors vary from green to mahogany-pink and the brightly fluorescent orange of phragmipedium besseae which was only recently discovered in 1981.

Watering
Phrags like clean water such as rain water, distilled or reverse osmosis (R.O.) system water.Almost all of the phrags in nature grow slightly on the acid side with pH ranging from 5.5 and lower. Municipal well water usually has limestone added to prevent pipeline corrosion. If the pH of the city water is 7.5 or lower, the following phrags will do OK potted in bark/peat mix: phrag caudatum, wallisii, lindenii, pearcei, Mexipedium xerophyticum, longifolium ecuadorense and amazon-icum. Phrag boisserianum and besseae require clean water to do best. Water should be applied copiously as the plant approaches dryness. Do not let these plants become totally dry at the roots between watering! If in doubt, water. Plants which like somewhat drier conditions at the roots include: caudatum, lindenii, wallisii, and Mexipedium xerophyticum.

Light
Most phrags will take more light than phalaenopsis or paphiopedilums. However, plants like besseae, pearcei and ecuadorense will do well in diminished light. Some phrags like caudatum can take light as for cattleyas.

Temperature
Phrags generally require intermediate temperatures with days in the 70's or 80's (degrees Fahrenheit) and nights in the upper 50's to low 60's. Some phrags like longifolium, sargentianum, pearcei, ecuadorense and hirtzii will tolerate slightly warmer temperatures. One problem that seems to occur during the summer is a soft, brown bacterial rot that appears at the base of the leaves. When you see this, carefully pull these infected leaves off and treat the plant with a bactericide such as Phyton-27.

Humidity
Grow in 50% to 70% humidity. Some phrags, like caudatum, can take humidity down to 35% in nature during the dry season, but the roots are always moist and the nighttime humidity is high.

Flowering
The flowering seasons are various but the best flowers are produced in the most abundanceduring the spring months. If the plants are not flowering for you, they either are not big enough to bloom or they are not receiving enough light or the cooler temps at night to initiate blooming.

Repotting
Repot every year in a mix of small coconut chips, spongerock and small charcoal. Examine roots and remove any unhealthy ones.

Zygopetalum

History: Sir William Hooker first described this genus in 1827 from a plant given to him by Mr. Mackay of Brazil. The name refers to the shape of the lip, the basal part which is very swollen and resembles a yoke that links together the two petals. There are 18 species of Zygopetalum, most of them being terrestrial and few epiphytic. The area of distribution is the entire northern part of South and Central America. The majority of species occur in Brazil at higher elevations.

Humidity and Watering
Zygos. thrive on abundant and regular watering. Good watering once a week should be sufficient for plants in larger containers. When plants have finished growing towards the end of summer in August you can give them a 2-3 week rest, and at that time it is only necessary to spray the compost so that it does not dry out too much. In the plants native habitat, this is the season of drought a condition essential for inducing the inflorescence.

Light
Zygopetalums need filtered light or moderate shading or morning sun. Full sun in the afternoon can be harmful and will burn the foliage.

Temperature
They prefer temperature range of the following: Daytime 60 to 85 degrees, night temperature 40 to 60 degrees.

Repotting and Compost
Zygopetalums do best in a light compost which holds moisture and has good drainage. This might be a mixture of fine and coarse Douglas Fir Bark with a small amount of coarse perlite(10-15%). Containers should preferably be plastic and large enough to allow root to spread out freely. The roots, in fact, grow rapidly but are quite delicate and do not lend themselves readily to repotting. This should be done every other year in the summer months or during the rest period.

Propagation
The simplest way is by division at the time of repotting. Repotting methods are the same way as cymbidiums. Other methods are seed production or mericloning

Disease and Pests
If it is too hot and dry there can be problems with spider mites which should not happen along coastal regions. A common trait is a Bacterial leaf spot which primarily affects the older foliage which is deciduous on many plants. Good air circulation and cooler temperatures are important to help reduce and eliminate the spots. If the condition persists or gets worse Antibacterial and fungal sprays are beneficial.

Growing tips and orchid culture