Hi kvalentz - can I ask why you feel you need these products? Neither is normally associated with starting seedlings.

Superthrive is marketed as a vitamin-based fertilizer - sold with an awfully lot of hype I might add - mixed in water, and used on established plants - primarily trees per their website. It has no research supported role in starting seeds or use on seedlings that I know of.

Messenger is marketed as a "plant health activator" - again, no role in germinating seeds but I have read info from others who find it helpful in treating fungal diseases on established plants.

A search here at GW by product name may pull up past discussions on these products perhaps they can be of help to you.

Dave

Dave,
I just like to try new things and this interested me. thank you for your help.
Kathy

I haven't used Messenger but have heard good things about it. I do use Superthrive but not for starting seeds. I use ST for transplants, cuttings and stressed plants and have found it to be a very good product. I also use B-1 for transplants and cuttings.
Karyn

Dave, there is now a Messenger product directed at starting seeds. Said to 'increase uniformity in germination', but I haven't seen it, haven't used it myself.

Apparently dusted onto the seeds dry before sowing -

Here is a link that might be useful: Messenger for seeds