When you don’t kill weeds you teach them how to survive

As any gardener can tell you, root sprouting species are a pain to get rid of, as they can regenerate from even small root fragments. So why don’t more plants do this? Jana Martínková and colleagues took pairs of plants from the same genus with different root sprouting abilities and put them through a series of tests to see how they grew back.

We found differences in growth and acquisition strategies and carbohydrate concentrations between root-sprouting and non-root-sprouting herbs. These differences suggest that [root sprouting] species are better prepared for severe biomass removal, although this advantage was not fully manifested by regenerated aboveground biomass in our experimental plants. Based on our findings, root spouting ability presumably represents a valuable strategy under disturbance, although it seems that only more severe disturbance that removes all axillary buds would unequivocally favour [root sprouting].

Martínková et al. 2022.

The team found that root sprouting required a low auxin-to-cytokinin ratio, two hormones plant use to regulate development. However, balancing the two is important and plants that have too low a auxin-to-cytokinin ratio risk developmental deformities. So it’s the plants prepared for the greatest disturbances that will invest in root sprouting.

Read Why is Root Sprouting Not More Common Among Plants? Phytohormonal Clues and Ecological Correlates by Martínková et al. at Environmental and Experimental Botany