I think that garlic will work fine. You can use a water bath canner or a steam bath canner – but you need either one of those to properly seal the jars. Sorry for the incorrect link. I’ve fixed it: https://www.amazon.com/gp/product/B0000DDVMH/ref=as_li_qf_asin_il_tl?ie=UTF8&tag=melskitcaf0b-20&creative=9325&linkCode=as2&creativeASIN=B0000DDVMH&linkId=2b53645dcd7f209be06b0641dbb4edab
This is how I make mine, minus the Cumin. I’m going to try it the next time I make a batch. Family and friends are always asking me to make them some. It’s so easy and sooooo good!! Sometimes I can it too. All you have to do is put it on the stove and heat it up slowly, then into your cleaned and prepped mason jars. It keeps for about 3-4 months unopened.
We use almost the same identical recipe. I add some fresh lime to add some acidity to the canning process. Also the recipe  my wife was given doesn’t “can” in the traditional way. After jars & lids are sanitized & filled, put lids on & tightened down, they are placed in a preheated 200 degree oven for 40 minutes. The oven is then turned off & left in oven overnight to cool off. We’ve made it this way for 4 years now & are teaching several others this fall
A note on chili varieties: Mexican cuisine uses a wide variety of chilies with different names and characteristics – most of them essential to the final result of the dish they are used in. You should be able to rather easily acquire the chilies described in this (and future) post cheaply online. If you’re having trouble finding these chilies, I suggest you stick to a mix of Ancho (a mild, fruity variety) and Chipotle (a hotter, smoked variety). Both are readily available and this blend will still lend you quite a bit of the complexity.

We find that while the jalapenos created quite a spicy salsa right off the bat, it mellows considerably by the next summer. So, if you plan to make your salsa last through the year, you might want to make it a bit spicier than you prefer to allow for the peppers to mellow. Tasting (with a clean spoon) is key when you are adding your peppers to the vegetable mixture; so that you find a heat level you are comfortable with.

Here is a tasty homemade salsa to accompany your crispy tortilla chips.  Many salsa recipes call for canned tomatoes and chilies (i.e., already cooked).  I find that using fresh ingredients, and then cooking the salsa briefly, yields the best flavor.  It sweetens the tomatoes and brings out their flavor.  (Note, canned tomatoes have also been semi-cooked)  The other purpose cooking it serves is to bring the mixture up to the required temperature for canning.
If I could suggest–instead of all the calculating and worry about PH in this, or other recipes due to minor changes–I bought an electronic PH liquid meter from Amazon for about $12.99 and you just dip it in the liquid food, pool, or aquarium–and instant PH! Your salsa with my lime juice exchange was a comforting 3.6 PH. I would never just make up a canning recipe and depend on that inexpensive meter to be safe, but it lets me double check on all my tomatoes & water bath canning and the recipes I carefully choose for safety from Pinterest.
Absolutely love this. You were right. Getting as much water out is so really important step. I drained as best I could with colanders then put in glass bowl. More liquid settled so I used a turkey baster to remove more liquid. Won’t ever make it another way. I have been looking for a salsa that has body and flavor and this is outstanding. I made my own tomato sauce as the tomatoes I got from local farmer were meaty and very flavorful. Thank you for posting this outstanding salsa recipe.