Basidiocarps (fruit bodies) are thin, effused, and web-like, but the fungus is more typically encountered in its anamorphic state, as hyphae and sclerotia.

The name Rhizoctonia solani is currently applied to a complex of related species that await further research.

[4][6] Molecular research, based on cladistic analysis of DNA sequences, has largely supported the division of R. solani into AGs.

Rhizoctonia solani sensu lato causes a wide range of commercially significant plant diseases.

It is one of the fungi responsible for brown patch (a turfgrass disease), damping off (e.g. in soybean seedlings),[10] black scurf of potatoes,[11] bare patch of cereals,[12] root rot of sugar beet,[13] belly rot of cucumber,[14] banded leaf and sheath blight in maize,[15] sheath blight of rice,[16] and many other pathogenic conditions.

[4] R. solani primarily attacks seeds of plants below the soil surface, but can also infect pods, roots, leaves, and stems.

R. solani may invade the seed before it has germinated to cause this pre-emergent damping off, or it can kill very young seedlings soon after they emerge from the soil.

[3] Cereals in regions of England, South Australia, Canada, and India experience losses caused by R. solani every year.

The pathogen can also release enzymes that break down plant cell walls, and continues to colonize and grow inside dead tissue.

The disease cycle begins as such: The pathogen is known to prefer warm, wet weather, and outbreaks typically occur in the early summer months.

A combination of environmental factors has been linked to the prevalence of the pathogen, such as presence of host plant, frequent rainfall/irrigation, and increased temperatures in spring and summer.

[6] The fungus produces white to deep brown mycelium when grown on an artificial medium and can often be recognized by the hyphae which are frequently monilioid (forming chains of swollen hyphal compartments), 4 to 15 μm wide, multinucleate, and tend to branch at right angles.

[19] Controlling the environment, crop rotation, using resistant varieties,[4] and minimizing soil compaction are effective and non-invasive ways to manage disease.

As long as seed growers stay clear of wet, poorly drained areas while also avoiding susceptible crops, R. solani is not usually a problem.

[21] In the United States, Rhizoctonia solani can be found across all areas (environmental conditions permitting) where its host crops are located.

The discrepancy is explained by the aneuploid, highly repetitive genome of this species which prevented sequencing (or assembling) the complete DNA.