It depends on the recipe, but I have never made that substitution. Lemongrass is very easy to grow, and you can easily grow it in pots if you do not want to put it in the ground. I have two pots of lemongrass now, but I had it in the ground when I lived in Venice. It seems to spread more when it's in the ground, but I don't trust my ground here, which is why I have it in pots now.

Lemongrass is a very different flavor from lemon rind or lemon juice. I think a better substitute might be lemon thyme. Cooking changes the flavor of lemongrass very much whereas it has less of an effect on lemon zest or juice. It's important not to overcook lemongrass, as the flavor can get a bit bitter if you boil it too long.

I used to substitute regular lime leaves or zest for Kaffir lime leaves, and while it is not exactly the same, it is a much better substitute than lemon zest is for lemongrass. However, I now have a Kaffir lime tree, and so I no longer have to make that substitution. I have a cold right now that doesn't want to go away, and so I have been making a lot of Thai soup.

If you grow lemongrass and end up with too much, you can store the excess in the freezer, and it will keep there very nicely.

Lars

Here's what The Cook's Thesaurus says:

Substitutes: lemon zest (zest from 1 lemon = 2 stalks lemon grass) OR lemon verbena OR lemon balm OR lemon leaves

Here is a link that might be useful: The Cook's Thesaurus - Asian Herbs

Lars ~ thank you for the hands on info. My lemon grass died (twice!). Your Kaffir lime sounds wonderful.

Grainlady ~ great link. Lemon verbena will grow here. And it confirmed I shouldn't order dried lemon grass from Penzey's.

Grainlady, I think the Cook's Thesaurus is just trying to substitute as an Asian flavor, but not for the same flavor as lemongrass.

In other words, forget that Cook's Thesaurus and read Lar's post again. He is right. Just because it's called Lemongrass, it has no relation to lemon and lime. Lemongrass tastes and smells differently than lemon and lime zests. Although, lemon/lime zests and leaves accompany with lemongrass and ginger quite well in many asian dishes, they are still not a substitution for lemongrass. They don't smell the same and they don't taste the same. Lemongrass is basically... grass! It grows like grass too.

Remembering from my childhood in Vietnam. One time we moved temporarily in this house that sat in front of a large tall grass field. I was amazed at the site of this field because we didn't normally see grass growing in large field like we see here in the US. Well, it didn't take long for my mom to realized it was a Lemongrass field thay got out of hand and grew wildly. That was when I learned how lemongrass grew... in abundance! Words spreaded around quickly and within a few months, the field was emptied. My mom had to claim part of the field in order to keep them growing for family cooking.

Anyway, you sure brought back some fond childhood memories, thanks.