The Orchid House

Phragmipedium Culture

phragmipedium
Phragmipedium longifolium

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.

WATER

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 O.K. potted in bark/peat mix: Phrag. caudatum, wallisii, lindenii, pearcei, longifolium ecuadorense, amazonicum and Mexipedium xerophyticum. 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.

FERTILIZER

Use GrowMore Urea Free 20-10-20 with municipal water or a Cal-Mag 15-5-15 with rain water, distilled, or R.O. water. Feed more heavily in spring and summer, less in fall and winter. Feed every third watering in summer at full strength and every fourth or fifth during the winter months.

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 or Agri-Strep or streptomycin.

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 abundance during 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 1 - 2 years in fresh bark. Species best suited to bark mixes include caudatum, wallisii, lindenii, sargentianum and longifolium. Many phrags love a rockwool medium. Use Pargro medium mixed with 10% fine charcoal and 35% coarse perlite for drainage. (Plants potted in rockwool should be flushed with clear water every 2-3 weeks, as the rockwool can build up minerals.) Since rockwool does not break down, repotting is easy, as the plant can simply be lifted out of the old pot and set into the new, larger pot, filling in the void with new rockwool.

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