the act or process of reproducing plants by a division of roots or crowns.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
Examples from the Web for root division
Historical Examples of root division
Aquatics are propagated by seed sown under water: many will allow of root-division.
The plants will grow readily in any light soil, and are easily increased by root-division in the spring, or by seeds.