A major challenge in the field of proteomics is obtaining high‐quality peptides for comprehensive proteome profiling by LC–MS. Here, evaluation and modification of a range of sample preparation methods using photosynthetically active Arabidopsis leaf tissue are done. It was found that inclusion of filter‐aided sample preparation (FASP) based on filter digestion improves all protein extraction methods tested. Ultimately, a detergent‐free urea‐FASP approach that enables deep and robust quantification of leaf and root proteomes is shown. For example, from 4‐day‐old leaf tissue, up to 11 690 proteins were profiled from a single sample replicate. This method should be broadly applicable to researchers working with difficult to process plant samples.