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Author Topic: 'Expiry' of SAf Seed  (Read 3393 times)

cohan

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'Expiry' of SAf Seed
« on: October 13, 2009, 07:25:25 PM »
i'm looking for some advice:
i need to choose some seed from a south african supplier to replace seed that did not germinate last year (they'd 'inherited' stock, much of which was of unknown age),
but the problem is, this is still mostly an old list, so i want to avoid species (such as almost everything i ordered last year) which need to be really fresh..
i dont mind if i dont get perfect germination, but most of the seedlots are fairly small, so 1 in 100 wont cut it if i'm only getting 5 seeds!

i had ordered some small bulbous things--eriospermum, lachenalia, ledebouria, ornithogalum etc, with virtually no germination, so i'm wondering, are there other genera of small bulbs that might be ok with older seed? albuca?
what about succulents--i failed with haworthia and bulbine in the same shipment; how about aloe, astroloba, crassula, adromischus, ceropegia or other stapeliads?

any other recommendations on small SA plants that might be tolerant of older seed are welcome--i'm still going through the list, they do have a few of many many genera..

johnw

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Re: 'Expiry' of SAf Seed
« Reply #1 on: October 13, 2009, 07:36:16 PM »
Cohan -  Have you tried this German supplier?

http://www.koehres-kaktus.de/agb_en.htm

Their seed was excellent when I last ordered from them and the list was lengthy.

I can always send you leaves of these to root next spring:

ADROMISCHUS
Adromischus cooperii
Adromischus cristatus - form
Adromischus cristatus v. zehri
Adromischus festivus
Adromischus halosowensis
Adromischus maculatus
Adromischus phillipsiae
Adromischus trygynus
Adromischus sp. - Animab, Vroolsdrif


johnw
John in coastal Nova Scotia

Diane Whitehead

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Re: 'Expiry' of SAf Seed
« Reply #2 on: October 13, 2009, 07:55:00 PM »
I discovered some old seed - at least four years old - and I remember
that Albuca came up surprisingly fast.

I'll check to see what else did.
Diane Whitehead        Victoria, British Columbia, Canada
cool mediterranean climate  warm dry summers, mild wet winters  70 cm rain,   sandy soil

Paul T

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Re: 'Expiry' of SAf Seed
« Reply #3 on: October 14, 2009, 07:24:32 AM »
Cohan,

You may still find that quite a few of the seeds will germinate this coming year.  I have often found that some seed from the northern hemisphere seems to take an extra year to germinate here, where seed from this hemisphere would germinate the first opportunity it has.

I know that I have had very old Lachenalia germinate that was held dry for many years as seed without a problem.  So many of the South African genus are built to cope with fluctuating seasons, so they can sit and wait for the right conditions to germinate.  Albuca should do find as well.  The fleshy Amaryllids of course won't last for any period of time, but the non-fleshy such as Massonia etc will last for years and germinate just fine when sown.  I would think that any of the arid area plants would have to have mechanisms where the seed survives for long periods of time dry as well.

I still think you'll find that a number of things will germinate given time anyway, but if you've got a chance for replacements seed then you might as well take it.  8)

Good luck.
Cheers.

Paul T.
Canberra, Australia.
Min winter temp -8 or -9C. Max summer temp 40C. Thankfully, maybe once or twice a year only.

cohan

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Re: 'Expiry' of SAf Seed
« Reply #4 on: October 14, 2009, 08:18:47 AM »
thanks for input-
diane--maybe i will try some albuca, they have a couple of interesting (i.e. small!) species..

john--i will be very happy to try some leaves of those adros, i have A marianae herrei (light green form) you might like...
i havent ordered from Koehres, though i have looked at their list a bit; i'm not making any new orders right now though, just trying to replace some of what i got last year...

paul--i dont have much experience with these seeds, but i have been told several of these need to be very fresh, and should germinate very quickly if they are going to;the supplier themself described some of the seed as 'dodgy' (now that is, not before i ordered...lol) and has said they are trying to sort out old seed they were left with;
i did not throw out any pots, kept them moist for several months, then let them dry out over summer, i rewatered in fall again, but no sign of action..
interestingly, massonia was one of the few that did germinate for me, though a friend had supposedly the same seed, and nothing came up from that..
i suppose one of the mechanisms you are observing is that some seeds will germinate right away if fresh, and dormancy has not set in, but once dried more time or other factors are needed to break dormancy..

Paul T

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Re: 'Expiry' of SAf Seed
« Reply #5 on: October 14, 2009, 09:24:39 AM »
Cohan,

Personally, I would never let any seed dry out after sowing.... ever!  Once the water absorption process is started my understanding is that letting the seed dry out is terminal and will kill the developing embryo.  Those plants that take a couple of years to germinate can tolerate it more because it takes that long for the water to break through the outer levels of the seed (i.e getting rid of the germination inhibitors) so the embryo itself is still insulated inside.  I never let any of my seed pots dry out, well not deliberately anyway.

To others reading this, if my understanding is incorrect then please let me know.  I've certainly always thought that once sown seed should never be allowed to dry out, but if that is incorrect then I would very much like to know.

Thanks.
Cheers.

Paul T.
Canberra, Australia.
Min winter temp -8 or -9C. Max summer temp 40C. Thankfully, maybe once or twice a year only.

cohan

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Re: 'Expiry' of SAf Seed
« Reply #6 on: October 14, 2009, 09:49:13 AM »
Cohan,

Personally, I would never let any seed dry out after sowing.... ever!  Once the water absorption process is started my understanding is that letting the seed dry out is terminal and will kill the developing embryo.  Those plants that take a couple of years to germinate can tolerate it more because it takes that long for the water to break through the outer levels of the seed (i.e getting rid of the germination inhibitors) so the embryo itself is still insulated inside.  I never let any of my seed pots dry out, well not deliberately anyway.

To others reading this, if my understanding is incorrect then please let me know.  I've certainly always thought that once sown seed should never be allowed to dry out, but if that is incorrect then I would very much like to know.

Thanks.

my knowledge is by no means extensive either, however, with plants from semi/arid places, this is a recommendation i have received before--if seeds have not germinated in the first season, they are allowed to dry in what would be the following dry season, watered again come the next rainy season; similar i guess to cycles of cold and warm for cold climate plants;this is an approach suggested by a friend who germinates tons of seed of cacti, succulents and other xerophytes/caudiciforms, trees...
 i don't think any of these have long germination like trilliums etc (i'm just as interested as you though if anyone has anything to add or contradict!)--its more a matter of dormancy needing to be broken and then they germinate quickly enough--i dont think plants from arid places can afford to dilly dally half germinated in the soil--once they start they need to hurry up before it dries up again..

those few seeds i had from that seed order that did germinate did so within a fairly short time, and the much greater failure of species was also experienced by several friends who ordered at the same time-- at least a couple dozen species between us; the one friend who did better had mostly caudiciform seed which is presumably less negatively affected by aging...

Rogan

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Re: 'Expiry' of SAf Seed
« Reply #7 on: October 19, 2009, 11:04:04 AM »
Don't get me onto the subject of South African (SA) seed suppliers - with some notable exceptions, they are the worst in the world!   >:(  Most SA bulb seed, unless it has been stored correctly in a refrigerator, won't last longer than a year or two and sometimes a lot less than that.

"...the supplier themself described some of the seed as 'dodgy' (now that is, not before i ordered...lol) and has said they are trying to sort out old seed they were left wi..."

I know exactly who this is, and they used the same excuse with me six or seven years ago! Excuse me if I sound embittered, but I have been stung by them several times now and I don't like donating my hard-earned cash to lost causes - by no stretch of the imagination can their seed and/or bulbs be labelled cheap, especially if you're buying in SA currency. Here endith the diatribe...   :D

Cohan, when I send you the promised seed, I'll put in a few others for you to try as well - are there any restrictions with importation into your country?
Rogan Roth, near Swellendam, Western Cape, SA
Warm temperate climate - zone 10-ish

cohan

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Re: 'Expiry' of SAf Seed
« Reply #8 on: October 26, 2009, 06:40:40 AM »
wow, rogan, if they have been using that excuse that long, that is beyond poor business, its outright deceit :(
they are currently still promising replacement seeds to myself and several friends in the u.s., and promising to only send fresh seed, with various interesting delays such as they will be landscaping this week....

well, i now know to expect nothing!

canada has no restrictions on seed imports apart from cites and restricted weeds, which are not likely to be growing in south africa; i have had no problems with any packets thus far...
thanks again...

fermi de Sousa

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Re: 'Expiry' of SAf Seed
« Reply #9 on: October 27, 2009, 06:47:21 AM »
Hi Cohan,
I've not had experience with some of the species you mention but I'm told that some do benefit from treatment with "smoke water" as they come from areas which regularly get burned.
My experience with seed from RSA is mixed - with some germinating quickly and some taking a year and others I'm still waiting for! ;D ;D ;D
cheers
fermi
Mr Fermi de Sousa, Redesdale,
Victoria, Australia

cohan

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Re: 'Expiry' of SAf Seed
« Reply #10 on: October 27, 2009, 07:54:49 AM »
thanks fermi--
i think i'd probably have to wait for another lifetime for any of these to germinate ;)
had the seed been fresh, the most definitive answers i've had suggest they should have come up right away/within weeks at least; i know there are species/genera which are tricky/slow etc, but i havent really seen any suggestion that anything i had was of those types..
by contrast, a friend who got mostly caudiciform seed from the same source at the same time, had good results--those are more commonly things which dont mind or even need some aging..

Darren

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Re: 'Expiry' of SAf Seed
« Reply #11 on: October 27, 2009, 01:03:53 PM »
Just noticed yesterday that I have a number of newly germinated Lapeirousia oreogena and jacquinii. These were sown in August 2008 and one seed in each pot germinated. Following advice from a friend in the Southern African Bulb group I allowed the pots to fully dry out and kept them at room temp this summer then watered again in late August. This demonstrates that re-drying the ungerminated seed was not detrimental in this case, and this is also the best germination I have ever had of any Lapeirousia species. This also worked for some Massonia which failed to germinate last year, and a Romulea too.

I have failed to germinate any Eriospermum and note that the Goldblatt & Manning encyclopedia of Cape bulbs states that eriospermum are not viable for very long.
Darren Sleep. Nr Lancaster UK.

cohan

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Re: 'Expiry' of SAf Seed
« Reply #12 on: October 28, 2009, 06:35:56 AM »
Just noticed yesterday that I have a number of newly germinated Lapeirousia oreogena and jacquinii. These were sown in August 2008 and one seed in each pot germinated. Following advice from a friend in the Southern African Bulb group I allowed the pots to fully dry out and kept them at room temp this summer then watered again in late August. This demonstrates that re-drying the ungerminated seed was not detrimental in this case, and this is also the best germination I have ever had of any Lapeirousia species. This also worked for some Massonia which failed to germinate last year, and a Romulea too.

I have failed to germinate any Eriospermum and note that the Goldblatt & Manning encyclopedia of Cape bulbs states that eriospermum are not viable for very long.

thanks for that input, darren

i havent seen any germination on the pots i dried and re-watered, but i havent chucked anything..
i've had at least 3 different erio species seeds, from 2 sources, and nothing at all...

Darren

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Re: 'Expiry' of SAf Seed
« Reply #13 on: October 28, 2009, 08:13:37 AM »
A further thought. I think we still don't really understand the ripening process some seeds go through after they are produced. For example:

Hesperantha vaginata (the lovely yellow/chocolate one). My own seed sown the autumn after collection (i.e about 4 months old).

2007 - no germination out of several hundred seeds
2008 - 100% germination very quickly
2009 - no germination yet and I'm not hopeful either.

All sowing times & conditions were the same.

2007 was a very cold & poor summer and I thought that failure was due to the seed not ripening properly so in 2008 I stored the seed in the house during summer (fairly constant 20C) and germination was superb. In 2009 I left the packeted seed in a cool place again and there was no germination again. I wish I had the time to experiment properly with this.
Darren Sleep. Nr Lancaster UK.

cohan

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Re: 'Expiry' of SAf Seed
« Reply #14 on: October 28, 2009, 07:51:28 PM »
A further thought. I think we still don't really understand the ripening process some seeds go through after they are produced. For example:

Hesperantha vaginata (the lovely yellow/chocolate one). My own seed sown the autumn after collection (i.e about 4 months old).

2007 - no germination out of several hundred seeds
2008 - 100% germination very quickly
2009 - no germination yet and I'm not hopeful either.

All sowing times & conditions were the same.

2007 was a very cold & poor summer and I thought that failure was due to the seed not ripening properly so in 2008 I stored the seed in the house during summer (fairly constant 20C) and germination was superb. In 2009 I left the packeted seed in a cool place again and there was no germination again. I wish I had the time to experiment properly with this.

just to be clear, were all the sowings from seed collected the first year? or was it seed from each year sown the same year?

 


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