It takes about 200grams of processor chopped wild garlic to fill a 175ml jar.
A plastic shopping bag holds about 500g of wild garlic leaves.
I would guess it would take about 500g of chopped leaves to fill a jam jar.
Chopped leaves are stronger than whole leaves.
When making pesto you probably don't want to add to the natural strength because it is quite hot.
Make sure you wash the leaves to remove any woodland grubs, tiny snails etc - unless you don't mind eating them. As you wash the leaves pick over them to make sure that they are all wild garlic because the plant grows alongside poisonous plants such as cuckoo pint.
A handful of fresh leaves that you might put in a salad, or any other meal, or even in sandwiches weigh hardly anything 2 grams at the most. A teaspoon of pesto would equal something like a really big double handful of fresh leaves.
Unwashed wild garlic leaves dry very easily in the oven and breakdown easily with (clean) fingers and when dried they have a slight but noticeable smell of sulphur.
When left to air dry the leaves turn yellow but when oven dried they stay green.
I haven't measured quantities of dried leaves yet.
I wonder if oil can be extracted from the leaves?