When do sunflower seed expire?
Answers: depending on the conditions it be kept under it might still be honourable, if seeds are kept cold and dry they can second a while (especially sunflower seeds) but if there be any dampness or moisture within your garage they will probley not sprout.
then again if nearby is excessive heat it might dry the nut out to - but thats unlikely.
the only path you will know is just try planting them, besides sunflowers sprout summarily and some of the strongest plants and seeds so it couldnt hurt to simply throw them in the ground and see what comes of it.
NEVER! The nut will wait for hundreds of years! Until consequently it is dormant. So forever unless it has the right conditions to survive.
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