Trigger effects when declaring summon

[johanessen]

Opponent has in play:

Darksteel Citadel
Darksteel Citadel
Forbidden Orchard
Forbidden Orchard
City of Brass
City of Brass

He plays Desolation Giant with kicker cost.

I say I end the phase with 2 Spirits and he says not.
My reasoning is the following:
If he doesn't tap the F.Orchard first and explaining what color does he get from the lands -and therefore putting the tokens on my board before playing anything else- (he didn't), trigger abilities from Orchard go on the stack so Giant's cip resolve first.

Who is correct?

[luma]

In any case, you have no tokens. If (as you said) your opponent taps his Orchards before casting Desolation Giant, you get the tokens before he casts the Giant and the tokens will be destroyed.

If he taps the Orchards as he casts Desolation Giant, the token-creating triggers go on the stack when he finishes casting Desolation Giant. The Giant is already on the stack (the first thing of casting a spell is to move it onto the stack), so the triggers go on top of the Giant and resolve before it. Therefore, you already have the tokens when the Giant resolves and wraths the board.