Saturday, January 22, 2011

How to grow Sarracenia to perfection - about growth patterns

Different Sarracenia species produce pitchers at different times of the growing season, with only a few species producing pitchers at a more-or-less constant rate. In some species, pitcher production can also be affected by humidity and temperature. Understanding these patterns can help you choose the right combination of species to ensure a constant display, and also produce better looking plants. It also helps you to choose the best performers for your climate.

In short - every Sarracenia species can be categorised into one of three types of growth.

They are:

  • Spring peaking - plants that produce their best pitchers during spring and early summer, followed by weaker pitchers and phyllodia in autumn. Some of the more brightly coloured Sarracenia flava clones (notably all var. rubricorpora) will start producing phyllodia in late spring or early summer, even under perfect conditions. Species: Sarracenia flava, S. oreophila.
  • Summer-Autumn peaking - plants that generally produce pitchers throughout the growth season, but have their best pitchers in late summer and autumn. Spring and early/mid summer growth tends to be comparatively spindly and floppy (even if only slightly so), often with large pitcher wings (alas). This growth type involves two (biphasic) or three (triphasic) pitcher types. Species - S. leucophylla (biphasic), S. rubra (biphasic), S. alabamensis (triphasic in ssp. alabamensis, nearly monophasic in ssp. wherryi), S. jonesii (barely biphasic), S. psittacina (biphasic).
  • More-or-less constant - plants that produce pitchers with relatively little difference throughout spring, summer and autumn. Species - Sarracenia minor, S. alata, S. purpurea and S. rosea.

As with all aspects of nature, these patterns are generalised and there are extremes within each case. For example:

  • Sarracenia flava generally produces beuatiful pitchers through spring and summer, but different varieties stop earlier than others. Sarracenia flava var. rubricorpora produces between 1-5 pitchers per growth per season, even under the best conditions, and is done by summer in some clones. In contrast, other varieties (eg. S. flava var. rugellii) may produce 5 or more pitchers and will keep going almost all through summer. They will stop well short of autumn, though, and produce phyllodia. If it is a good season, you may get some autumn pitchers, but they always are very phyllodia-like in appearance, with huge wings or ala.
  • Sarracenia oreophila will produce a very brief but intense burst of pitchers in early Spring, but will abruptly stop in early summer to produce phyllodia. The pitchers die back quickly, leaving the phyllodia by mid to late summer, regardless of what you do.
  • Sarracenia leucophylla always produces tall, spindly pitchers in early spring and can pitcher continuously if humidity stays high during the entire growth season, but will produce only phyllodia during summer if humidity drops away early in the growth season, with pitchers again forming in autumn. If you have a greenhouse, you can induce S. leuccophylla to pitcher more or less continuously (and sometimes entirely skip phyllodia production, if you are lucky!), with a sudden change between pitcher types in late summer.
  • Sarracenia psittacina always produces long, thin traps with relatively small hoods and huge wings throughout spring, before producing their characteristic lobster-pot traps by mid-summer. I wish the older books told you this. As a 9 year old who had just forked out three month’s pocket money for a big pot of S. psittacina fresh out of dormancy, I was terrified that my prize plant was dying!
  • Sarracenia purpurea can also produce early pitchers with huge wings and relatively small mouths and hoods, but this phase disappears quickly and does not extend beyond spring (given normal light conditions – if large ala are produced past spring, then the plants probably need more light).
  • Sarracenia alata produce reasonable pitchers in spring, but their best growth occurs during the height of summer.
  • Sarracenia minor is similar to S. alata, but its pitchers are more reliably attractive in spring, especially after a cold winter.
  • Sarracenia rubra complex species (except S. alabamensis spp. alabamensis)typically produce really crappy looking pitchers in spring and summer, before producing magnificent pitchers in late summer and autumn. Some, like S. rubra ssp. gulfensis, do this to a much lesser degree.
  • Sarracenia alabamensis is unique in producing three pitcher types during one season – read on to see what I mean.

Here are some examples to show what I mean (this is a work in progress).

Late summer/autumn peaking taxa: triphasic pitcher production in Sarracenia alabamensis ssp. alabamensis.

Sarracenia alabamensis ssp. alabamensis  

This S. alabamensis ssp. alabamensis beautifully show the three pitcher types this species produces. The first pitchers are the flopped over ones, with smaller trap openings and lids and relatively large pitcher wings. It then goes on to produce normal looking but still floppy and somewhat spindly pitchers through summer. In late summer and autumn, it then produces the largest pitchers of the year, which are completely upright and more rounded.

Here is a closeup of the two floppy pitcher types, which are not distinguishable in the above photo. The spring pitcher has an enlarged ala, while the mid-summer pitcher is floppy and somewhat spindly.

I am trialing a kind of formula to describe the growth of individual Sarracenia clones shown on my blog. It is:

Sp (n) - Su (n) - Au (n)

Where n is the number of pitchers produced. This formula should not be taken as a ratio; I don't have data showing that pitcher production throughout the year is relative (at least not yet). This is why I use dashes, not colons, to separate seasonal growth. I'm aiming to collect data over many years to see exactly what patterns emerge.