A high throughput drought screen is described for Arabidopsis that is based on a gravimetric method to monitor and control water content of the soil. To screen for plant growth under mild drought conditions, 30% of field capacity can be used, which is equal to 2 g H(2)O/g dry soil. The screen allows the testing of a large number of plants of different sizes to the same level of soil water. Therefore, response to drought of different genotypes can be compared. This method can be used for knockout or overexpression genotypes, which are evaluated for their drought response in terms of their growth measured by change in biomass.