Pick nettles for eating at any time until flowering. The younger ones are more tender and delicious, while those closer to flowering are stronger in medicinal content. There are also hemp nettle, hedge nettle, and false nettle. The only stinging varieties in our area are stinging nettle, tall nettle, and wood nettle. Tall nettle can get up to nine feet high, but I have only seen it once or twice.
Wood nettle is a plant of moist woods that grows in vast patches.
Its leaves are alternate, rather than opposite, and broadly egg-shaped. So try, respectfully, to get to know this valuable plant. You may, of course, harvest nettles with gloves.