Winnower's Ambush

If {w} was spent to cast Winnower's Ambush, creatures you control gain +1/+0 and First strike until end of turn. If {g} was spent to cast Winnower's Ambush, creatures you control gain +0/+3 and Wither until end of turn. (If you spent {w}{g}, do both.)
If both {g} and {w} were spent to cast Winnower's Ambush, put a +1/+1 counter on each creature you control.