Using a water bath to can tomatoes is different.  Tomatoes are usually a high acid food …like other fruits and do not need the pressure canner higher temps for canning.  However, even tomatoes now are sometimes not even recommended for water bath canning—because they have such varying amounts of acid in them. 

I have a pressure canner that I can vegetables and other low acid foods in.  
 
For canning jams, jellies and fruits….I use my large pots and make a water bath to can in—making sure the water covers the jars and putting a kitchen cloth on the bottom of the pot for the jars to sit on. 

http://pennypantry.com/in-the-kitchen/recipes-in-the-kitchen/using-up-excess-squash-and-zucchini/

The USDA no longer recommends canning squash and zucchini so you won’t find a recipe in the newer canning books. 

I canned this squash at 10 lbs of pressure for 40 minutes…in a pressure canner.  But that was only after talking to more experienced canners, seeing a few blogs that canned squash and finding a few older canning books that still had squash canning times in them. 

Of course, canning times and temps and procedures have changed over the years……one year one thing may be right…the next year it isn’t.  So that is unfortunately what you will run into once you start getting into canning. 

However, I talked to a few experienced canners around in my area about how they can squash.  I also was able to search for a few blogs out there that had pictures of how they canned squash—so there is nothing “official” about canning squash or zucchini thanks to the USDA. 

So unfortunately you won’t find it in the new canning books.  I’ve seen recipes for canning squash in older canning books though.  So with a combination of reading those recipes, talking to experienced canners and viewing other blogs that canned squash—I canned our squash. 

I didn’t follow a ratio—I just started cutting and slicing and chopping and mixed up what I had….blanched it and then loaded it into my jars.  I processed in a pressure canner at 10 lbs of pressure for 40 minutes. 

I know that isn’t very detailed…sorry….

When I use this squash…..I will be cooking it in the oven in a casserole or cooking it again in soup—

For the Squash casserole: 
I add eggs, salt, milk, mayo and whisk it together.  I pour the mixture over the squash/zucchini and tomatoes and bake at 350.  Sometimes I add cheese on top if I have it.  I also sometimes add hamburger or sausage meat to it.

I don’t have an exact recipe because many times when I am cooking I alter recipes so much that I sorta make up my own.