PBS Forum

Quote from: MarcR on June 24, 2023, 03:59:46 PMCrinum like to be moist but not wet all year. 

It depends on the species/hybrid and minimum winter temperature.

Ignoring natans and thaianum, my Crinums are all under glass (actually bulbispermum and boophanoides are on a cold, west-facing kitchen window sill) and although x powellii and macowanii can take several degrees of frost, I keep all of them except variable dry for the winter (greenhouse minimum is around 6C), and would not risk things otherwise.
Some SA Crinums are native to areas with very dry, dry seasons, some are baked into something akin to concrete while dormant. During their active growing season, some are semi- or fully aquatic, although the vleilelies are supposed to flower perfectly well if just kept well-watered rather than submerged, with a dry season.

Quote from: David Pilling on June 23, 2023, 10:30:21 AMFor example if you can manipulate temperatures you could generate two (or more growing seasons) per year.

It is generally (always?) temperature cycles controlling active growing periods, although the warm/cool periods usually need specific minimum lengths to flick the clock over - peonia seeds are a very good example which can be artificially taken through two cycles in one year.

For flowering, it is generally (always?) photo-period, or ratio of dark to light, that triggers things - pointsettias are a very good example.

There are also some plants that grow unlinked to phoo-period or temperature, but grow so long as conditions allow - one comes to mind - some Crinums, which grow so long as there is enough moisture - uncommon in nature, but not so in cultivation. But, they will need a short-long day cycle, and wet-dry, to trigger flowering.

Contact Dr Christian - he is pretty anal about plant ID's and may well help.

Many amaryllid seeds are notorious for germinating within almost no time of maturing - seeds will send out a root before falling in some cases - so-called ephemeral seeds.

I bought a pack of Crinum asiatica seeds back last year and got around 80% germination within a very few weeks with just 2-3 showing nothing. Around 3 weeks ago, the pots were transferred to the greenhouse from the indoor propagator and today two more seeds have a root.

It depends on the plant - many will go dormant as the day lengthens and temperatures rise, and they will rot if kept watered.

Many bulbs depend on dormancy to trigger flowering once mature.

Quote from: Martin Bohnet on June 03, 2023, 12:24:38 AMRelax on that breathing thing - as long as you don't eat fossile fuels it will be regenerative CO2 somewhat recently bound by plants.

Only to a point - all food would have to be raw unless using solar or a wood-fire. It also ignores transportation.

In terms of straight CO2, there is lots of work going on to run jet engines on modified vegetable oils, which work just fine, but you quickly hit the problem that there is no way vegetable oils of any kind, from any source, could make much of a dent in fuel demands.
The downside beyond CO2 are the believed effects of what amounts to con-trails, which some reckon are considerable.

You can only use them once, but black plastic will take a very long time to degrade and become brittle, so I use cheap black labels by preference, and scratch/engrave the information on them.

Anything that stays in the greenhouse has white labels written on with pencil. They do become brittle, but it is seldom a problem leading to lost ID.

Darvic (bird) rings were made from Darvic as it was reckoned to be "indestructable". But sadly, not so.

All plastic detriorate because the C-C bond energy is around the same as the energy of a UV photon - an exceedingly unfortunate coincedence, but fact. UV absorbers help, but they are slowly destroyed - they are especially effective in what would otherwise be very short-life polymers - PE in particular - try some with and without as greenhouse insulation.

More than anything else, deterioration of plastic will depend on aspect - put it on a north-facing aspect and it will last, put it on a south-facing....................... (in the N hemisphere).

Adding cheap wood (as a filler) to expensive plastic (even as reclaim) is simply economy and nothing to do with longevity.

25 year guarantee - who is going to claim? I very strongly suspect that the wooden fence at my parents' place was far older and still functional.

Quote from: David Pilling on May 11, 2023, 05:16:26 PMI was surprised when a neighbouring house that was being renovated got plastic fences. There is quite a bit of plastic used in construction now - uPVC cladding. This house has some external plastic which has been exposed to the light and the weather for 60 years and is as good as new.

Missed that....

Probably the vast majority of garden products made from plastic, are made from 100% recycled, usually made black to disguise any unsightly bits and bobs in it. Boards for confining raised/no-dig beds are the obvious ones in the UK. So-called builders' buckets are another.

Like all plastic, most especially outdoors, it does become extremely brittle - I have had a dummy security camera in place for something over 10 years - that will be ABS, but the cover fell off and all but "shattered" a week or so back.

The uPVC gable and barge boards that were installed before I moved in 23 years ago, have been covered in algae to some extent for quite a few years and they can't be cleaned as the algae sit in little erroded pits in the surface - special paints have been available to refresh exterior uPVC for well over 10 years.

Exterior plastic will be fine until it has to be moved or take a load - fall against some 10+ year old plastic fencing and it will be no more. The same goes for uPVC fascias and the like - fine until something hits them or you need access behind them for some reason.

LOL - "fragranced" - probably phenols/cresols - it is difficult to imagine anything else having a similar smell, so just using pure chemical components rather than the mixture that comes from coking ovens.

TCP is still available, albeit the phenolic ingredient(s) has/have changed over the years.

It is a long while ago now, but I used to work where TCP and DCP (tri- and di- chloro-phenols) were used and they arrived in 40 gallon drums form Coalite Industries (which probably means something only to UK readers). 
The drums were obviously filled with warmed/liquid product and were one hell of a job to get relatively small amounts out of at any one time (at normal ambient temperatures they are both crystalline solids). No doubt the usual/large usages used drum level quantities at any one time, and they just warmed the drums and poured the contents out.

No problem. Presumably Wright's Coal Tar soap is still available??
I have not searched.

A friend had seborrhoeic dematitis years back - it itched like you would not believe and caused hair loss - nothing else worked. They used Polytar every once in a while whenever an itch started.

How they produce the correct ingredients minus the trace nasties, who knows? Maybe just formulate umpteen phenols and cresols rather than use actual coal tar product - they are what you can smell and likely the active ingredients.
There are still coking ovens for steel-making so by-products will be available.

UK labelling is usually Coal Tar Creosote - just a by-product from coking ovens back in the day.

I love the smel of creosote (still very much available outside of the UK/EU, I believe).
I also have friends with contacts/licences.......................
Do not be fooled though - creosote  is extremely unpleasant. Maybe 30 years ago, when creosote was "legal", I lived not far from a unit producing soaked/pressure-treated timber, and an employee fell into a vat of it. The manager threw him into his very expensive car and got him to the hospital in tme - a lot of the active ingredients in creoate are absorbed through the skin. The employee survived and it made local news.

Personally, I dissolve bitumen in it to form something akin to black tar varnish - even better protection than straight creosote.

Polytar Scalp Shampoo 150ml, Treats Psoriasis, Seborrhoeic Dermatitis, Eczema, and Dandruff, Soothes Itchy, Scaly Scalps, Contains Coal Tar : Amazon.co.uk: Beauty

Plastic in the garden has limited life, longer if black, but it becomes very brittle eventually.

In the UK, if you can find it, sweet chestnut will last 20+ years in soil contact.

As for treatments, there are none that the amateur can legally use that achieve any real increase in life of the timber. The great white hope to replace creosote - commonly called CCA (copper, chrome, arsenic), now contains only copper, along with cypermethrin.

I can't remember the last time that I saw real timber railway sleepers, either under railway tracks or in farm supply yards (often the traditional, preferred material for building clamps). Garden centre "sleepers" are just standard softwood baulks, and they last no time at all in many soils.

Creosote is available to anyone with a pesticide licence. It was banned due to extremely low levels of chemicals such as dioxins. It is also available to anyone as part of shampoo formulations. 

In Zantedeschia (all aroids), the pollen is produced above the stigmas - at the right moment, in the plants here, a gentle tap of the flower or stem produces a dense blizzard of pollen which must fall on any receptive stigma.

If you have just single flowers of any single species that is self-sterile, that can't be over-come. Some aroids also have different times for pollen production and receptivity of the stigmas.

The only observation that I can offer is that at least some Zantedeschia are easily fertilised by tapping the flower gently once a day for as long as the flower remains fresh.
I can get close to 100% seed-set this way.