The application of second harmonic generation (SHG) microscopy to plant materials has been neglected hitherto even though it would seem to have promise for identification and characterisation of biologically and commercially important plant polysaccharides. We have found that imaging of cellulose requires rather high laser powers which are above optimal values for live cell imaging. Starch, however is easily imaged by the technique at laser fluences compatible with extended cell viability. This also has useful applications in imaging plant-derived starchy food products. Lignin in plant cell walls shows a strong 3-photon excited fluorescence which may be enhanced by resonance effects.