Its difficult to say without knowing the particular varieties of seed you are sowing. Gibberlic Acid-3 is for seeds that are difficult, usually shrub or tree seeds. J.L. Hudson indicates which seeds have several conditions which must be met to unlock dormancy and the catalog indicates the ones that would benefit from treatment.

I just planted a mixed package a couple weeks ago, some needing cold stratification. I usually sow in fall which is best around here but I picked up this batch rather late. I did cull out the lupine seeds from the pack and soaked them for 24 hours in hot water but other than that, I just went ahead and sowed the seeds. I expect good results. Our days fluctuate from the upper 60's to below freezing but the nights are cold. Here we have more days that are mild rather than very cold.

Needing cold is a natural safeguard to prevent the seeds from sprouting in summer or too early, some seeds only need cold temps while others need a period of cold, the time required varies from one type to the next.

If you are worried or you expect your weather to be more warm than cold until spring, you could mix the seed in damp vermiculite or sand and keep them in the fridge and then sow in spring.

Below is a sowing chart that gives conditions for many different seeds.

Here is a link that might be useful: http://tomclothier.hort.net/page02.html

Here is another sowing chart.

Here is a link that might be useful: http://tomclothier.hort.net/page02.html

This post was edited by GreatPlains1 on Wed, Jan 22, 14 at 14:52

My gut feeling is yes...usually 60 days is sufficient for most things. However, having said that there will be something that requires 90.