Stubborn Seeds

[Mark$]

I have some old seed that refuses to come out of the casing when doing a test germination. I know that the seed is good because when I see it swell after about a week I have been dissecting the seed to find the live embryo inside. It appears that it can't push through the seed coat. Any suggestions on helping to get old seed germinate would be helpful.

[Darren Abbey]

In lab studies, it is not uncommon to perform "embryo rescue" with difficult-to-germinate seeds. The basic idea is that the live embryo is dissected out of the seed and grown up in a sterile tissue-culture setting.

Cutting through the seed coat, while not harming the embryo and endosperm would be finicky, but may be worthwhile for hard-to-find seeds.

[Patihum]

I assume we're talking tomato seed and you're doing the paper towel baggie thing. Is there a possibility you're just not giving it long enough and maybe need to go 2 weeks or even more? Some people soak their older seed in tea or a weak solution of Miracle Grow before hand. If it's a common variety I'd probably just buy new seed.

[carolyn137]

Mark, how old are the seeds and how have they been stored and how many seeds do you have to work with?

Over the years I've had to wake up many older seeds and would be glad to tell you what I think is best after trying all sorts of methods..

My best wake up was seeds of September Dawn that were 22 yo.

Carolyn

[KarenO]

I wonder if nicking the seed coat or rubbing the dry seeds gently between sandpaper to scarify them and allow the water to penetrate the dry seed coat more easily would help? If there is enough seed to try a different method, how about pre soaking in warm water overnight and then sowing them in very moist seedling media over bottom heat and see if they can make their way out of the seed coat in a more natural way. They must be special seeds to go to so much trouble.
KarenO

[Mark$]

I am going to try scarifying the seed with sandpaper to see if that helps. Maybe that and the warm water soak afterwards will help with germination.

[carolyn137]

Originally Posted by Mark$

I am going to try scarifying the seed with sandpaper to see if that helps. Maybe that and the warm water soak afterwards will help with germination.

Mark , I wrote what's below, but not getting back any answers, b'c it does make a difference depending on answers as to which methods you might choose I'lljust go ahead.

&&&&&&

Mark, how old are the seeds and how have they been stored and how many seeds do you have to work with?

Over the years I've had to wake up many older seeds and would be glad to tell you what I think is best after trying all sorts of methods..

My best wake up was seeds of September Dawn that were 22 yo.

Carolyn

&&&&&&

Scarification of the seed coat alone is not going to help b'c tomato seeds don't need to be scarified and b'c it's the endosperm that needs to be awakened , thats thne seed embryo.

After trying:

warm and cold teas of different kinds
Microwave
K nitrate soak
Paper towels and baggies
Giberellic acid

Try this:

Put seeds in a small container with plain water, I don't know how many since I don't know how many you have nor the seed age, nor how they were stored.

Old seeds float, so stir until they sink

Add a pinch or two of blue stuff, that means MG or Peters, stir, or use a few drops of organic fish or seaeweed emulsion ( fertilizer) Both of those products have a high concentration of nitrates, which have been shown to participate in seed germination/

No need to put the container in or near something warm, just stir from time to time when you are awake, ahem, and soak for at least 24 hours, longer if I knew the seed age and conditions or storage.

Sow wet seeds in artifical mix as you normally would, cover the container with plastic or put in a baggie, but do NOT close those up, you have to leave room for air to circulate.

Water with a dilute solution of either the blue stuff or fish stuff, as needed.

Again, depending on the seed age and specs of seed storage, it may take a month or two before you see any germination at all, and sometimes no germination, it can happen/

When I have very low germinating seed I do the same and then just double sow to be sure I get some plants.

With 5 yo seed I expect to get about 50-60% germination with no treatment.

From 5-10 yo I will treat if the varieties are hard to get/rare.

Over 10-12 years if it's an impotant variety I will treat.

My seeds, going back to 1991 and I've never thrown out a saved seed, were stored in vials up to about 1995. Since then they are just stored in regular envelopes at ambient conditions. and for my area that means not that much humidity in the summer that lasts for weeks on end, and the default setting on the heat in the winter in that back room is set at 62F and in the summer I've never seen the temps be over 80-90F for days on end.

I hope that helps,

Carolyn

[Mark$]

Thank you for the tips. I thought saltpeter would do the trick until I read where it doesn't really work. Since it is Potassium Nitrate, it should supply the nitrogen needed to assist in germination and therefore should work.
My seeds are from 1999 and have been stored at ambient temperature in glassine bags.

[carolyn137]

Originally Posted by Mark$

Thank you for the tips. I thought saltpeter would do the trick until I read where it doesn't really work. Since it is Potassium Nitrate, it should supply the nitrogen needed to assist in germination and therefore should work.
My seeds are from 1999 and have been stored at ambient temperature in glassine bags.

It's nitrates, not nitrogen, which is N2 and a gas, that is known to help promotion of germination.

And for 15 yo seeds I sure would treat them as I outlined above.If you have plenty of seed you could also try double sowing those seeds, no less than about 20 seeds to get a couple of plants, and double sowing usually means sowing twice the numberof seeds you would normally sow, but 15 yo seeds need treament.

What is the variety, I went back and never saw you say what it was. If it's a heart, then there are more problems. And if it's a common variety, heart or not, I wouldn't go through all the trouble with questionable outcomes. I'd just buy new seeds.

Carolyn