Prepare a boiling water bath canner and enough jars to hold between 4 and 5 pints of product.

In a large, non-reactive pot, combine the chopped fruit (no need to peel nectarines, their smooth skin breaks down nicely during cooking), sugar, and lemon juice.

Set the pot over high heat and bring to a boil. Reduce the heat to medium and cook the fruit for 30-40 minutes, until the volume has reduced by at least 1/3 and it no longer looks watery.

When you're satisfied with the consistency of the jam, remove the pot from the heat and stir in the rose water (its flavor is fragile and so I don't add it until the active cooking time is up).

Ladle the jam into the prepared jars.

Wipe the rims, apply the lids and rings, and process in a boiling water bath canner for 10 minutes.

When the time is up, remove the jars and set them on a folded kitchen towel to cool. When the jars have cooled enough that you can comfortable handle them, check the seals. Sealed jars can be stored at room temperature for up to a year. Any unsealed jars should be refrigerated and used promptly.