This section is from the book "The Gardener's Monthly And Horticulturist V23", by Thomas Meehan. See also: Four-Season Harvest: Organic Vegetables from Your Home Garden All Year Long.
The Lynchburg Advance, published in the heart of the Sumac region, says: "Gather when the leaves are full grown, say from June to August. Only the leaves and the small stems on which they immediately grow can be used. Keep it clean of all sand, sticks, berries and trash. Remember that sunshine or rain or heat in bulk spoils it. Keep it under shelter and well dried. When properly cured the leaves will have a rich green color as when on the bush, and will easily crumble in the hand. It requires five or six weeks to cure."