hi, on my on quest to find juniper berries in uk have found a website, www.natoora.co.uk, which offers 40g jar of organic berries, for around $5. not sure what the postage costs would be if you would want to try those. every other stockist i found listed only offered dried berries, good luck, quxi.
You can pick the bluish-black berries off the juniper bushes, but heaven know where you'd find them in the city, Central Park possibly, doubtful where you are in Queens, or maybe you have friends outside the city that have the one correct variety of juniper bushes on their property. Please read the NYT article linked here before you go out to harvest. Why is it that you did fresh berries for your gin? Most preparations use dried berries with great results:
Content from chow: "General Description: Juniper (Juniperus communis), an evergreen tree, has small round berries (rightly called cones) that take three years to mature from pale green to fleshy blue-black; they have a piney, refreshing aroma reminiscent of gin. The berries are the only spice from the Coniferae (evergreen) family and one of the few native to cold climates. Several species of Juniperus grow across temperate Europe and Asia, but the best quality berries hail from southern Europe. Picking the berries, which each contain three sticky, hard brown seeds, is no easy task, because they’re nestled among needlelike foliage and are soft and easily crushed."
Photos of Juniper bushes and berries, not necessarily the correct variety:
Good luck in your search and enjoy your gin!