Is economic growth merely a monetary phenomenon?

Economic growth involves both monetary and fiscal measures . 

No economic growth is not a merely monetary policy phenomenon, in fact, it has been proven that monetary policy only has short term impact on the economy. In the long run any monetary policy has no effect, this is, in the long run the impact of monetary policies are totally absorbed by the formulation of new expectations on form the economic agents. For a quick example, lets say the central bank of an economy decides to undertake an expansive monetary policy with the objective of increasing economic growth ( for example, lowering interest rates to stimulate economic activity), in the short run we will see economic growth due to easier access to credit, but as time passes and the central bank stops its stimulate program economic agents will be aware of this and act on conformity with this, this is, they will reduce or stop investing because the access to credit will not be so easy as it was during the stimulus program. In the long run the monetary policy will have no effect because of inflation expectations, as period by period the price index in the economy will adjust itself to the stimulus program, this is, the price index will rise  and the exchange rate will weaken (in general) taking the economy to the same point of well being it was initially. So after a stimulus program and given time to adjust the economy will return to the same total output, but with a higher price index.

The only policies that have effect in the long run will be fiscal policies, and structural policies. The more effective policy in by far the structural policy, as it will grant the economy with a greater production capacity, and a lower cost of production. Structural policies have  very wide range, as they can go from restructuring labour market conditions, government functions and expenditure, health and education reforms, and many other areas.

Economic development is not merely a monetary phenomenon. There are short term and long term development policies. Short term development can be associated with monetary capital investments, whereas long term development is associated with human capital, technology and institutional quality.