Known in its native India as the "queen of spices," cardamom has flavored dishes set before Roman nobles and medieval kings. Today, this relative of the ginger plant is a common coffee flavoring throughout the Middle East, a spice for sweets in Scandinavia and a constituent in curries throughout southern Asia. While cardamom's warm, resinous sweetness has no exact substitute, other spices share some of its characteristic flavors and can pinch-hit for cardamom, if necessary.
Nutmeg's warm, woody character approximates cardamom's flavor and aroma. Like cardamom, nutmeg is strongly aromatic and lends itself equally well to sweet and savory dishes. But nutmeg lacks the brighter citrus and menthol components of cardamom's taste and aroma. Nutmeg is more accessible and less expensive than cardamom, but it lacks the latter's complexity. Substitute nutmeg for cardamom in recipes in equal quantities.
Cardamom and cinnamon share a similar warmth of flavor, but cardamom lacks cinnamon's heat. Because of its distinctive flavor, cinnamon works best as a component in a spice mixture used as a cardamom substitute -- not as an exact substitute by itself. Cinnamon tastes familiar in sweets and candies, but it can quickly overwhelm a savory dish. Use half as much cinnamon as you would cardamom in a sweet recipe. In a savory dish, cut the cinnamon to no more than one-fourth of the amount of cardamom specified.
Roasted coriander seeds have a warm, nutty flavor with citrus overtones. Their size and flavor profile make them a good substitute for whole cardamom pods, particularly in savory recipes. Although coriander seeds come from the same plant that produces the herb cilantro, the two taste nothing alike. Coriander seeds make a viable substitute for cardamom, but cilantro does not. Substitute the seeds of this parsley relative for cardamom directly in savory recipes. In sweet recipes, cut the amount of coriander in half.
Allspice tastes like a blend of cinnamon, clove, nutmeg and pepper with a hint of cardamom. It's logical, then, that allspice could double as cardamom in recipes. Allspice doesn't have the warmth cardamom does, but it matches cardamom's expansive fragrance well. Allspice's flavor lingers more than cardamom's, so use a lighter hand with it than you would with cardamom -- no more than one-fourth of the amount called for as a cardamom substitute.
While no single spice exactly matches cardamom's flavor profile, spice blends can approximate it. Mix equal parts of nutmeg, coriander and allspice for a plausible cardamom substitute in savory dishes. In place of cardamom in sweet recipes, use a blend of 4 parts of nutmeg to 1 part each of cinnamon, clove and allspice. To mimic cardamom's citrus overtones, add a small quantity of orange zest to either blend. Finish the spice mixture with a pinch of ground ginger.