The author tested a polysaccharide (guar) derived from guar bean (Cyamopsis tetragonoloba L. Taub.) was tested in soil flocculation tests and found that use of acid solutions to fully dissolve the guar leads to more effective soil conditioning than otherwise would be possible, and that guar does not lead to strong water-stable aggregates. Larger quantities were needed to improve emergence and growth of plants in a glasshouse than for synthetic soil conditioners. The effects of soil conditioning with guar did not last long.