wheat/wood require water to grow. If your resources are too far away from water or if there is no water on the map nothing will grow. There has been talk of adding a building that creates water to increase growing areas but nothing has happened so far.
do not be afraid to joust a giant just because some people insist on believing in windmills.
the speed of groth of wheat/wood depends on the ratio water/land in the 21x21 (or was it 31x31)-box surrounding the resource. "1"-wide waters count as land (globs can walk on it)