To get the highest yield gardeners grow many small plants rather than a few large ones, mostly they strat with feminized marijuana seeds. Smaller plants yield more per square foot of space, mature faster, and are easier to care for than large ones. People used to think that size or age were important, but they soon found out that maturity or ripeness is the important factor. As the buds on the plant ripen, their potency increases. Depending on how intensive the technique and the variety being grown, plants are forced to flower when they are between 8-15 inches tall. Mature plants reach a height of 18-30 inches. Plants forced when they are small have little chance to develop side shoots. This means that each plant uses not only a smaller vertical space, but has a smaller radius. Plants which are flowered when they are very small can be placed very close together. Short plants use much less vertical space so gardeners often find it convenient to divide the growing area into several levels of shelves or bunks.