1 teaspoon
No use tarragon instead
How big a sprig? You must be specific. But 1/2 tsp dry ground thyme = 1 tsp fresh thyme if that is any help. That's the leaves not including the stem.
Dried herbs are normally twice as strong as fresh, so 1/2 a tsp.
I will repeat an answer found within the other good answers: Rule of thumb is 1 tsp dried herb substituted for 1 tablespoon fresh herb.
How much ground thyme do I use in place of chopped thyme
1 teaspoon ground = 1 tablespoon fresh. Ground or dried herbs are actually stronger than their fresh counterparts.
You can't really measure it that way, despite what the books say, which I very much refute on. It's said that 1 tsp of ground thyme is equivalent to 2 and half tablespoon of fresh thyme. But it changes when you blanch your fresh thyme first - That's when they are activated. Their smell goes stronger, their 'stem' bursts out in flavor and everything in the herb goes wild. Same goes to other strong herbs like dill, rosemary, etc.
One fresh bunch of thyme is roughly equivalent to one teaspoon of dried thyme.
If you mean dry thyme for fresh thyme, then plan for 1/3 as much dry as fresh. If the recipe calls for 3 tsp of fresh thyme, use 1 tsp of dry.
thats what I want to know
The definition of thyme is any of numerous plants belonging to the the mint family.