Patrick Costello is matching peaches with lavender both for preserves and syrup (More Canning and Whoa Lavender Peach Syrup!).
Sometimes when preparing stone fruit, you might have bits and pieces of fruit that you can't really use, such as the parts that cling to the stones in clingstone fruit (especially likely
Sake + Cheese fell in love with giardiniera and when the supply she bought ran out, decided to make her own (The Canning Continues: Hot Giardiniera). Good call. This is one of the most satisfying pickles to make. The flavor is rich, has plenty of depth and is texturally eclectic. Not too mention it looks spectacular.
Moo Said the Mama has an excellent photo essay on making and canning ketchup, well worth checking out if you're thinking of making some (Ketchup Canning Tutorial). MStM does note that the recipe they used ended up tasting more like cocktail sauce than ketchup. That is a problem with ketchup recipes, they do vary a lot in terms of flavor. As I've noted before, we're used to that commercial flavor. Don't be surprised if your ketchup tastes different. (Although I look for clove and celery seed in recipes ... they are definitely two flavor keys to ketchup, as far as I am concerned) Keep trying recipes until you find one you like. And know also that the sweetness of homemade ketchup can vary a great deal depending on the sweetness of your tomatoes. The golden cherry tomatoes from my garden are crazy sweet, while my Romas are sweet, but not like the cherry tomatoes.
The National Post also provides a recipe and description of making homemade ketchup (Field Trip: Canning Tomatoes).
If you're a canning beginner, this first time canning experiment by Frugal and Focused would be a useful experience to read about (Learning the Art of Home Canning: Experiment #1 - Blueberry Syrup). Yep, fruit syrups can boil over very easily. Use a big pot. Syrups might seem a bit thinner than you're used to. Don't thicken them before canning, but thicken just before use, if you choose to thicken them at all.
The Santa Cruz Sentinel interviews a local canner, Anna Cameron of Ladysmith Jams, who uses many foraged fruits in her preserves (The new can-do spirit: Santa Cruz jam maker savors the fruits of her foraging).
"It's something to see that little piece of heritage," she said. "But foraging goes back to an even deeper genetic history. Even before we were hunters, we were gatherers. Picking fruit calms me, it makes me feel human in this world of business and to-do lists and screen time. Go pick blueberries down an alley and you'll feel better!"The article also has a brief history of canning.