How to sprout or grow from very old seeds or ones hard to sprout.

Hello friends and family. I'm looking for more serious help in getting one of my old seeds to sprout. I've tried to sprout my perennial sunflower seeds in my greenhouse, but it's a tough nut to crack. I've done my very best to resurrect some of the rarest veggies and stuff, but most my efforts have been a wash. Any tricks and stuff to aid me? Please reach me if there's anything to add. Take care!

Many species of wildflowers drop their seeds on the ground in the fall. Then they require like 3 months of cold/damp conditions before the seeds will sprout in the spring.  Perennial sunflowers may fall into that category.

Cold stratification is often recommended for wildflowers.

One method that I saw being used to start milkweed seeds was to put the seeds in milk jugs with dirt and set them outside all winter.

Everyone has some sort of different method they like to use:

https://permies.com/t/178454/Starting-attempts-cold-stratification

https://permies.com/t/67030/Alternatives-Cold-Stratification

https://permies.com/t/34978/Cold-stratification-alternatives-nature

As for trying to start old seeds, I use to methods.  The indoor method involves using the paper towel method.

The outdoor method uses just sowing the seeds in October and waiting to see what happens.  Usually, I get a few that sprout and I got rid of the old seeds.

What about old seeds of veggies or fruits? I've tried to grow rhubarb, a 100 year old one. I just got bad luck growing that type of seed.

How can we plant seeds in our greenhouses during the warmer months? I'm trying to protect my seedlings from the invading weeds and keep a strong population of native plants.

With old seeds, I plant a lot of them. If some germinate then happy day. If they don't, then I don't have to store dead seeds.

Many kelp varieties contain a lot of growth hormone and other biological stimulants that can activate dormant seeds and get really old seeds going.

The trick is getting them inside the seed, and that is achieved by using an organic acid. Humic acids like fulvic acid is the typical one.

You can find prepared solutions to purchase or make it yourself if you have the ingredients.

Are there some very effective and quicker techinques to help them sprout?

Have you tried the H2O2 (hydrogen peroxide) trick? I would try it different strengths/ different lengths of time. Could be quite the experiment/process though with the same result. A quick search will find it.

Mechanical scarification has worked well for me.  If the outer seed coating is really hard and thick, use nail clippers.  If it's thin or the seed might be fragile, use a nail file and sand it down.  Then place them in damp soil and hope they will do well.

I got some 45-year-old fig-leaf gourd seeds to sprout by presoaking them, using a nail clipper to remove the very edge of the seed coating to make it easier for the cotyledons to emerge, and placing them in damp soil.  I finally got some banana seeds to germinate by nail filing them, presoaking them, and putting them on top of damp soil (and it still took them five weeks).  Carob seeds did great with being nail clipped and then planted -- I got a 50% germination rate in about three weeks.

I doubled the germination rate of really old bean seeds by using Hydrogen Peroxide (H2O2) at 1.5 % (if I remember well). It is the same product which is in the contact lenses liquid.

It works by providing more oxigen to the germinating embryo.

As usual: germination depends on the species. Some need scarification, some need stratification, and if you use any products the time of soaking and the dosage depends on species and variety.