Your plan sounds like a good one. Any manure you got now would probably have to be composted for several months so it wouldn't burn the plants.
Can you get the soil tested? It seems wasteful to use a broad spectrum fertilizer when your soil may be deficient in only a few things. If you can't get the soil tested in time, try buying a few bags of composted steer manure and working that into the soil. It helps aerate the soil as it feeds plants gently.

FWIW, I'm not adding any fertilizer to mine this year. I sowed rye grass last fall and just finished mowing the last of it yesterday, plus till the roots in and let them decompose. I will add compost tea throughout the year (probably every other week until fruit starts setting).

If you can find some aged horse manure from a stable or maybe county fairgrounds, it is very fertile and does not need to be composted. I added a layer of that to another plot (a raised bed) and am getting a good fertility reading on a RapidTest meter.

Mike

I wonder about what sorts of pesticides & herbicides might have been used there. I recently inherited my grandfather's old gardening books. One sings the praises of DDT as a miracle cure. (yikes!)

I'm not saying anything like that was used in your plot in the past decade or so, but if you can talk to the person who gardened there, that would help solve the mystery. Or even look around their shed or what-have-you for old bags, etc.

Testing the soil should be the first thing you do. It might be a Ph issue, not just nutrients.

Do you get any sort of deciduous tree leaves in LA? Leaf mold is great stuff for gardens, too. We love it up here in New England.

What a nice thing to acquire - enjoy!

Talked to the neighbors gardener he works all over town he said he'd put money on needing lime. Im thinking he's probably right. I have a hand held ph meter I need to dig out and check