In a tightly sealed jar about 2 years is the maximum.
That is about 3 gm.
It takes about 4 weeks. After harvesting rosemary stems, hang in a group of 8, and hang in a dry, dark place. Then store in a air tight jar.
1 tablespoon fresh rosemary equals 1 teaspoon dried
One small sprig of rosemary converts to 1/2 a teaspoon of dried rosemary.
The herb is generally pulled off the stem when cooking with rosemary. Because the rosemary pieces are relatively long, they are usually chopped into smaller pieces before use. With dried rosemary, like what can be bought in the grocery store, the herb is already off the stem, and may be crushed in the hand before being added to the pot.
4 tsp of dried rosemary equals 1/4 cup fresh.
For rosemary, the ratio is three to one, fresh chopped to dried. So if your recipe calls for 2 tsp. of dried rosemary and you would rather use fresh, you will need three times as much, or two tablespoons of fresh chopped rosemary leaves.
Rosemary is an aromatic herb, most often used in cooking. You can find dried rosemary in the spice section of your grocery store. Grocery stores also carry fresh rosemary sprigs, if that's what your recipe calls for. Rosemary is also grown outdoors as an ornamental plant, often as part of an herb garden.
Approximately one teaspoon of dried rosemary equals one tablespoon of fresh. (Approx. 1 tsp dry = 1 Tbsp fresh)
For fresh rosemary substitute 1/4 tsp dried rosemary for each tsp fresh required Or equal amounts of oregano OR basil. For dried rosemary substitute: Dried savory, tarragon, or thyme.
Usually about three times as much, but if a recipe calls for fresh, do your best to use fresh. Dried rosemary is one of those herbs that does not do very well dried. Fresh vs dried makes a huge difference. Also, depending on the recipe, if you're using dried rosemary, don't leave it in the food. Let it sit to soak the flavor in and then strain/take it out.
It doesn't matter where you store them as long as no air can get in.