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Everything posted by Rob-Rah

  1. Rob-Rah

    Hardy pygmies

    Plants in a greenhouse usually don't receive "frost" as such. Frosts happen when water vapour in the air freezes on the leaves of plants. This in turn provides nucleii for ice to form on and in the plant's tissues, and which makes them freeze as well. When the plant tissues freeze, the water in the cells expands and the cells burst due to the increased pressure and ice crystals puncturing them. Then the plant is dead. In a greenhouse, even when the temperature gets below freezing, you tend not to have the nucleating vapour. The lack of nucleii for ice to form around means that plant tissues may go to below freezing but no ice forms in the tissues, so the cells do not burst, and the plant stays alive. You have supercooled water in the plant tissues instead. At a certain temperature below freezing this effect will stop and the tissues will freeze anyway. Normally somewhere between -4C and -12C. However, temperatures themselves don't tell you a complete story about what plants will tolerate! The effect of physical frost, and the effect of relative humidity is highly relevant. Interestingly, certain bacteria can precopitate the nucleation of ice crystals in plant tissues at higher temperatures, and hence make the plants less able to tolerate cold temperatures: http://www.ncbi.nlm.nih.gov/pmc/articles/P...30/?tool=pubmed Cheers. Rob.
  2. Everyone's ignoring the aquatic species! U. vulgaris and U. australis are great plants. Very big yellow flowers and free flowering. Large traps, easily visible (and you can hear them "popping" loudly when you move the plant out of water. U. purpurea is good coloured (though maybe a bit small - I wish the "large flowered" variant was in cultivation). U. inflata and U radiata have some amazing structures to support their flower stems, and nice big yellow flowers again.
  3. What would be the effect of stirring a load of bicarbonate of soda into the plaster mix? Or whipping it?
  4. I don't think it would do that well in the ideal conditions for N. amp, as it needs a great deal of light to flower: http://www.ukorchidforum.com/viewtopic.php?f=44
  5. In my tank with the N. ampullaria, I also have a Promenaea, which isn't very happy (I think it wants more light) and a Bulbophyllum echinolabium, which is doing nicely. However, there's a reason most tropical orchids are epiphytic.... they want more light and air than are found down on the ground whrere the N. ampullaria grows ;-) Some species of Paphiopedilum might do OK, but they would have to be kept somewhat drier at the root than the Nepenthes (but conversely are not very easy to grow epiphytically in a terrarium). Ludisia and Anoectochilus species might do well however.
  6. It pops up on eBay every now and then: that's where mine came from. (Or peruse the dealers' websites listed on the Orchid Forum itself)
  7. Bulbophyllum gracillimum (if you can keep it wet enough).
  8. I must have the plain species then. Mine are around half that. If any bits "fall off" you know where to post them.....
  9. mIne has been flowering merrily the last few weeks too. I'm not convinced mine is magniflora though - how big are your flowers?
  10. Don't cut the stems back until completely shrivelled (they wil then pull away with no effort at all). They continue to pump starch into the new bulb for as long as they can ;-)
  11. The only books I have which tell you how to grow it are: RHS Gardeners' Encyclopaedia of Plants and Flowers (1994): Sanders' Encyclopaedia of Gardening (1964) I'd say this would be more or less impossible to grow well in Europe, due to the lack of sunshine all year.... And pot-culture seems implausible due to the root morphology. Cheers.
  12. I've noticed that the Acacia dealbata trees (getting reasonably common round here!) were untouched by the hard winter and have flowered really well recently. Likewise the Agapanthus I see around are tough as nails. I can't grow Echiums or tree ferns for toffee. The merest hint of frost and they turn to mush for me. The only "garden" plant that has suffered this winter was Myrtus ugni. Feijoa, Embothrium, Grevillea and Lomatias completely untroubled. For CPS, the only plant that looks a bit unhappy is a Heliamphora heterodoxa which got scorched by freeezing (the pot was sitting in ice in the HEATED greenhouse!). The crowns are green though and I expect new growth to emerge - it has been cold before.
  13. Be careful, pondwater is often either heavy in nitrates or alkaline.
  14. For rare utrics, you'll probably get a small division. You'd call it a seedling if it were another sort of plant. It's enough, but nowhere near a potted plant size.
  15. Mine is in a mix of seramis, perlite, vermiculite, fine bark, and some dead sphagnum moss (in approximately decreasing order of amount)
  16. In that case, I'd revert to D. maculata being far more likely as part of the intergrading (not D. fuschii, which I have never seen in wet conditions, and which is not at all common in the New Forest). D. praetermissa definitely looks to be involved too, especially in pic 7. Cheers.
  17. I believe that these are. 1. Gymnadenia conopsea (fragrant orchid) 2. Dactylorhiz fuschii (common spotted orchid) 3. Anacamptis pyramidalis (pyramidal ordhid) 4-8. Dactylorhiz fuschii (common spotted orchid) Yes, all the same species. D. fuschii is a very, very variable species! The fact that the flower spikes are held clear of the leaves is typical of D. fuschii (most other Dactylorhiza orchids have leaves extending alongside the flowerheads, as well as amongst them). The other species which might be involved here is D. praetermissa, and there may be a degree of intergrading beetween the two Dactylorhiza species here. Especially in the penultimate photo. However, I'd still pop for all being D. fuschii if pushed.
  18. I've been growing H. heterodoxa under these conditions for almost 10 years. No problems. It's only a few nights a season that things get that low.
  19. I thought I'd say more about this (even thoug this thread was about Neps and not Helis in the first place)..... I just popped into my greenhouse, which hit -2C inside last night. The current air temperature in there is now around 2C and the water trays are still frozen solid. However, all the plants, including H. Heterodoxa still look fine, with no signs of cold-related problems. Cheers.
  20. H. heterodoxa does fine for me just kept frost-free (a degree above zero). N. khasiana is as cold-tolerant as the books suggest it should be, but does appreciate warmer days.
  21. Be careful: even though they are "on" the quality of light emitted degrades over time. If you can get a light meter it's useful to check how the bulbs are faring with extended use.
  22. Lovely shots! It now needs re-selecting for gigantism..... ;-)
  23. That moss looks like it is not sphagnum. The close-ups in the second pic show that the leaves are growing in a branched, flat-plane way. Not sphagnum. Are the plants planted straight into the mix? I'd be more inclined to plant into pots, with media more suited to individual plants, then disguise the pots with moss. What ping is that?
  24. P. primuliflora does this too, though not so prolifically.
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