Although the Melastomataceae are a very large family with many attractive herbs and shrubs, the family has been largely overlooked by horticulturists. That said, there have been some very notable and well known exceptions – people interested in the cultivation of melastomes should carefully consider the two species, Miconia calvescens and Clidemia hirta, described on the invasives page, and proceed with caution.
In terms of responsibly bringing species of melastomes into cultivation in areas where there is any potential for their escape and introduction into the local flora, it would be advisable to begin by considering those species that occur naturally in your area. In localities that lack native melastomes, you may wish to investigate nurseries and botanical gardens. Try to ascertain whether a species is capable of self-fertilization or not. If the plant can reproduce without outcrossing and the climate is favorable, then there may be some potential for invasive behavior. If the plant requires a pollinator (most melastomes with attractive flowers do), try to find out if any effective pollinators occur in your area.
In the southeastern United States, two melastomes are often used in landscaping. Tetrazygia bicolor, a beautiful shrub with large white flowers and yellow stamens, is the northernmost member of the Miconieae with its native range extending to the Miami, Florida area. Tibouchina urvilleana is tolerant of a wider range of climactic conditions and survives outdoors through mild winters. T. granulosa is a similar, but larger species; neither is considered to have much invasive potential.
Many other species that merit attention from horticulturists likely would not survive outdoors in most areas north or south of 20 degrees latitude. They may, however, be grown in pots which can be brought indoors for the winter. Alternatively, a great number of species thrive in greenhouses, and, if kept in such an environment, they pose no threat to the local flora. Some taxa that would make excellent additions to a greenhouse include Charianthus alpinus, Tetrazygia fadyenii, and several species of Bertolonia, Blakea, Medinilla, Melastoma, Meriania, Monochaetum, Phyllagathis, Sonerila, and Tibouchina, among others.
Being a rather unusual and largely overlooked family from the standpoint of cultivation in greenhouses, little information is available on propagation. Following are some comments about growing melastomes.
From Ron Determan of the Atlanta Botanical Garden (where a number of very attractive melastomes are in cultivation):
Melastomes are successfully grown in a potting mix also suitable for growing ericads. The recipe:
1 part peat
2 fine orchid fir bark
2 fine treefern fiber
2 milled sphagnum (no damp off)
1 fine charcoal
now mix mostly:
2 fine bark
2 fine charcoal
2 milled sphagnum, and variations thereoff.
From Dan Skean – Break apart a mature or dried fruit and scatter the seeds on sphagnum moss or moist vermiculite. The substrate and seeds/seedlings should be kept inside of a terrarium with high humidity. If algae develops on the vermiculite, use benylate to kill it. According to Dan, it is very easy to get the seeds to germinate and probably even grow most species to maturity (although depending on conditions in the greenhouse, they may or may not flower). Glassworks Greenhouse in Ohio used to sell a rare species of large-flowered Meriania that Dan gave them.
Solt, M. L. and J. J. Wurdack. 1980. Chromosome numbers in the Melastomataceae. Phytologia 47(3): 199-220. “…Seed germination and growth was best in a mixture of 3 parts bottomland loam, 3 parts peat, 1 part perlite, and 1 part sand; the mixture was overlain by shredded sphagnum, damping-off thus being inhibited. Since almost all the species sampled had quite small seeds, sowing was directly on the moist sphagnum.
“Seedling germination was generally rapid (1-2weeks) in capsular-fruited species, slower (1-2 months) in those with baccate fruits; the longest germination time after sowing was 4 months for Mouriri myrtilloides. Seedlings generally grew very slowly for several months, but thereafter more rapidly. They were transplanted nto flats and later into pots, using the above-mentioned soil mixture; this mixture was rather acidic, only a very few melastomes being calciphiles. All seedlings were grown under fluorescent lights (16 hours per day) until about 20 cm tall, thereafter in daylight on a sunporch or ( in the summer) in pots sunken in the ground out of doors.”