I see recipes with it and without it. The Blue Book doesn't have a recipe and I don't trust random recipe sites on the internet. Can I get an approved recipe?
You should book mark NCHFP. They are the most trusted site for canning recipes on the internet. They have both strawberry jam with liquid pectin and strawberry jam with powdered pectin.
Here is a link that might be useful: NCHFP - Jams and Jellies
The Blue Book has a couple of recipes - what edition are you looking at? I think the one(s) with pectin may not use lemon juice (I'd have to look) but I have made the "Heirloom Strawberry Preserves" w/o pectin and it uses lemon juice. Both batches came out rather stiff, goes to show you don't need pectin to get it to gel! I'm waiting for local strawberries to try again.
Oh, sorry, I see you said jelly not jam. But I bet you could follow the recipe I mentioned above (or any other for preserves) and just strain the juice out before letting it sit overnight to make jelly.
The NCHFP had jelly recipes too. That should've been the first place I looked. Thanks for the help!
If you're asking if strawberry jelly needs lemon juice for safety, no. Strawberries tend to be lower in pectin and some strawberry recipes do call for lemon to increase the natural pectin level and improve the set.
Strawberries differ regionally and by season; it can be difficult to determine which recipe will work best with your particular growing conditions, but either way is just fine as far as risk is concerned.