To make the tea, brew the tea by bringing 4 cups of water to a boil. Place 4 teabags in a pitcher and pour the water over the top. Let steep for 10 minutes. Remove teabags and discard.
Puree blackberries in a food processor strain though a fine mesh sieve to remove the seeds. Add puree and mint leaves to brewed tea. Mix well. Place in the refrigerator until chilled.
To make a single drink, fill a glass with ice and pour 4 ounces of the blackberry tea over the top. Add 4 ounces of lemonade. Gently stir, garnish with a lemon wedge and mint leaf.
Notes
Because the lemonade will have sugar, I don't find that this recipe needs any additional sugar. However, taste it after chilling to determine if you need a bit more sweetness. I like this with equal parts lemonade and equal parts tea. However, if you want a little more blackberry tea flavor, start with 2 ounces lemonade to 4 ounces tea. Nutrition information for estimation purposes only.