Berries start turning from green to red by the end of October. It is much easier to identify the females when the berries show. Female Yaupon are reported to have better flavor than males (Putz). But in the wild, berry-producing Yaupon are less common than the male, indeterminate, or juvenile plants. It takes extra effort and time to separate the berries from the leaves, especially if the berries are green. Berries are not harvested (they contain ilicin, glycosides of ilicic acid, which are possibly the emitic compounds of Yaupon, Ilex vomitoria).
Female flowers show in late March, by October there is ample terminal growth without berries (see the cover of Black Drink: A Native American Tea, Hudson 1979 for an illustration of a female plant with berries).
Fresh shoots often have purplish stems and are soft enough to pinch off without clippers. Young tender Yaupon leaf dries differently than mature leaf; they tend to curl, and the tender stems will blacken like the dried leaf.
Growth slows down in December and picks up again in March. The best time to harvest is November when the berries have begun turned from green to the red. Southern summers can be brutally hot and humid. Mosquitoes are prevalent in areas where Yaupon grows, near the brackish marshes under the shady oaks. West Nile Virus is active in the Southern coastal states. I dislike the taste of DEET, and certainly do not want to contaminate the Yaupon leaf product I pick with chemical insect repellents. So, if I harvest in the hot buggy months, I have to wear long clothes, shun repellents, and suffer the assault of insects. In November and December the weather has cooled enough that the mosquitoes have diminished, and it is comfortable to wear long sleeves and pants without becoming saturated in sweat.
Young Yaupon leaf from the terminus are brighter green than old leaf closer to the central stalk. Older shaded leaf can grow up to 2.5 inches in length. Flavor of old leaf is different than young, but there are fewer of them, and usually need to be wiped individually to remove dust and mildews. Young leaf is much cleaner.
Potential foreign material in the harvested Yaupon leaf includes: Spanish Moss which grows on the Live Oaks over the shady groves of Yaupon, invasive Chinese Privet which looks similar, tendrils from various vines usually Green Briar (Smilax) and Cross Vine (Bignonia capreolata), spiders sometimes make webs on the underside of leaves, some insects fold and modify leaves to protect eggs, birds may have left droppings, and older leaves can harbor growth of black mildew or smut. Another insect pest are leaf miners which make trails or tunnels inside the leaf.
The insects which fold the Yaupon leaf into egg cocoons are active all year long, and you can see them on the fresh terminus, or further back on older leaf. If the infestation is not great, curled egg-leaf can be plucked off while the Yaupon is harvested. In some locations most of the plant is infected. No insecticides or chemicals are used on the Yaupon groves I harvest. Infected plants are severely pruned, and the branches burned. I do not recommend spraying with imidacloprid, malathi0n, or diazinon or any other pesticide.
Small-scale Drying is done in a food dehydrator. This is the fastest way to process: wash leaves, dry stems with leaves on them for at least three hours at 130 F to 140 F, inspect and discard bad leaves, separate leave from stem, and then store, roast or grind. Dried whole leaf is quite stable at room temperature. They tend to be hygroscopic (absorb moisture from the air) brittle leaf becomes less so in a matter of hours depending on the humidity. After drying to brittleness, I store the Yaupon leaf in mason jars. Stems take longer to thoroughly dry, and are susceptible to molding if stored while incompletely dried.
The harvested Yaupon leaves (fresh or dried) can be pan-roasted. The leaves should be separated from stems first. Higher temperatures in the pan dry the leaves much faster, but the leaves must be stirred so they do not scorch. This method involves more labor and has small yields. Pan-roasted leaves have more caramelized flavors, and tend to dry out in green and dark brown colors. Be careful when roasting leaves in an oven/broiler. When temperatures reach the smoke-point necessary for rapid roasting, the Flash-point is not much higher and the Yaupon leaf can spontaneously combust.
Nov-4-2011. Minor changes Aug-31-2011. Edited Dec 2013