A plethora of seedlists at this time of year.

[Darren]

Once whisky is in the bottle keeping it serves no useful purpose. It's not like wine, so does not improve with age.

I can see why Australian seeds respond to heat treatment. They have evolved in a bush fire environment, so germinating after fire, when the area is clear of vegetation and is rich in nutrients is a useful trick. I have received acacia seeds with "wrap seeds loosely in news paper and set on fire" as part of the instructions.

I visited a commercial Erica nursery in South Africa once and their standard procedure was to sow Cape Erica seed onto the surface of damp substrate then pass a blowtorch over the tray. The exact speed of the pass and setting for the torch was something the owner had developed a feel for after years of trial and error. The Bainbridges technique (published in The Rock Garden) of using a domestic oven for a short time would be rather safer and more scientific, if not as much fun

[Darren]

By the way Lesley, I do agree with you about the listing of old seed.

If the person listing it knows what they are doing, and sticks to only keeping those species which are known for long viability then fair enough.

It was interesting to me when I obtained some of the old seed from Jenny Archibald's final clearance after Jim passed away. It did come with the clear caveat that viability was unknown. Of 15 species of Fritillaria only one showed any sign of germination. The 12 Allium species were a total loss.

I have not been able to find much information at all on longevity of Allium seed but my experiences from seed exchanges and from purchases from some sources suggest that the seed is surprisingly short lived?

[Peter Maguire]

pass a blowtorch over the tray

I assume a plastic pot/tray is not recommended? 

[Darren]

I assume a plastic pot/tray is not recommended? 

By all means try it if you like Peter..

I think they were using metal trays.

Before my recent greenhouse overhall I had terrible problems for years with tiny annual grasses seeding everywhere (They were the unintended legacy of an experiment for my degree course). For control each year I would do the usual early september bulb watering then after a week or so when the grasses germinated I'd use a hot air paint stripper over the top of the pots to burn them off before the bulb noses appeared. This brief treatment was tolerated by the plastic pots but I did melt a few labels....



This year Susan and I repotted EVERYTHING in the greenhouse, replaced the plunge sand and capillary matting and cleaned all the pots inside and out. So far this autumn - no grass

[Jonna]

Allium seed is germinating the best if it's not older than 1 year, but I  grew some Allium seeds with that were 2 years old.
I planted them in the same container as the fresh seeds.  The older seeds germinated later and more irregular and the germination percentage was lower, but still very acceptable.
There are some reports that older Allium seeds need a warm-cold-warm period to break their dormancy

[Tim Ingram]

I am fascinated by that idea of using a blowtorch for Erica seed. I wonder if any material was placed on top of the seed to burn because I thought the received wisdom now was that chemicals in smoke were important to stimulate germination.
I have a bottle of 'Liquid Hickory Smoke' which I thought I might try with seed from fire prone habitats - and if it doesn't work it 'imparts a wonderful smoky flavour to your favourite foods'!

[Lesley Cox]

The little blowtorch I was given as an aid to making the perfect creme caramel and like desserts, might be a good one to try. The flame is very small and concentrated, contolled by distance from the thing to be torched.

At my market, there are manuka smoked eggs. Ordinary eggs which are smoked over manuka shavings and the shells come out blackened but the egg istelf is unchanged so can be scrambled or whatever. The guy who sells them sells many many dozens to upmarket restaurants throughout the country and is even exporting to Australia and S E Asia now. Gordon Ramsey uses them - not that that's a recommendation. Bacon and smoked eggs a real treat.

[Darren]

I am fascinated by that idea of using a blowtorch for Erica seed. I wonder if any material was placed on top of the seed to burn because I thought the received wisdom now was that chemicals in smoke were important to stimulate germination.
I have a bottle of 'Liquid Hickory Smoke' which I thought I might try with seed from fire prone habitats - and if it doesn't work it 'imparts a wonderful smoky flavour to your favourite foods'!

No material on top of the seed Tim - reliance was on cracking the seed coat being enough. But - I can't guarantee a subsequent watering did not use 'smoke water'.

The research on smoke chemical effects is pretty extensive and convincing and the relevant chemical (a butenolide) will stimulate germination in synthetic form without any actual smoke being involved.

I've used the Kirstenbosch 'liquid smoke' for Cape Ericas with some success, percentage germination is reasonable but not exactly spectacular so I think perhaps the seed coat cracking is at least as important.
 Incidentally - with some of the Restio species I tried the smoke water was essential - absolutely no germination without it and plenty with. Sadly I can no longer afford the space for Fynbos plants like these, the bulbs have edged almost everything else out!

Lesley - I think your little blowtorch would be well worth trying!

[Darren]

Allium seed is germinating the best if it's not older than 1 year, but I  grew some Allium seeds with that were 2 years old.
I planted them in the same container as the fresh seeds.  The older seeds germinated later and more irregular and the germination percentage was lower, but still very acceptable.
There are some reports that older Allium seeds need a warm-cold-warm period to break their dormancy

Thank you Jonna - that is interesting and helpful 

[Maggi Young]

No material on top of the seed Tim - reliance was on cracking the seed coat being enough. But - I can't guarantee a subsequent watering did not use 'smoke water'.

Sorry, I could not help myself:

[Darren]

It's OK Maggi, some things are just too tempting to resist