>-not only do the plants have to be in active growth, but glyphosate must be administered to the foliage - >it's ineffective if sprayed on the stem or roots! This is not correct. Glyphosate binds so well to soil particles that if used properly it's not available to be absorbed by roots growing in same soil. This is not the same thing as saying it's ineffective if sprayed on roots. Spraying any part of the plant you don't want to kill, whether leaves, stems, or surface roots is taking a big risk. Regarding Adam's original question if he sprays Roundup only on the leaves of the Johnson grass, not on the soil, around his dormant bulbs, he'll get the desired result. The Johnson grass will die and the dormant bulbs will be undamaged. Regards, Jay