Recently, the ecological awareness of society and the need to take care of our surroundings and the natural environment has significantly increased. There is also an urgent problem of searching for new, environmentally friendly techniques for its purification (soil, ground and surface waters, sewage sludge and air) with the use of living organisms, especially higher plants. One plant species investigated for phytoremediation is canna. Ten varieties of canna, grown on degraded and garden soil, were tested in this respect. The disease index and species composition of fungi inhabiting its organs, growth dynamics, parameters of photosynthesis and gas exchange were determined. The conducted research showed that cannas are able to satisfactorily grow even in seemingly unfavorable soil conditions with its strong degradation. Among a total of 24 species of fungi obtained from its organs, genus Fusarium, considered as pathogenic for canna, Alternaria alternata, and, less frequently, Thanatephorus cucumeris and Botrytis cinerea, dominated. The cultivars ‘Picasso’, ‘Cherry Red’, ‘President’ and ‘La Boheme’ had lower rates of photosynthesis and gas exchange than the least affected ‘Botanica’, ‘Wyoming’, ‘Robert Kemp’ and ‘Lucifer’ cultivars. Those turned out to be the most beneficial and they can be recommended for cultivation on strongly degenerated soils.