Fallow may also be used to control perennials such as Canada thistle and perennial sow-thistle. With these species, the first tillage should be done at the bud stage. Food reserves are at a low at ...

As the creeping root system of Californian thistle is deeper in the soil than the residual herbicide, the plant is unaffected. No other thistle species in New Zealand is a perennial. Other species are ...