I dunno. When difficult weeds grow inside a lily clump, if I can't remove them right away, I usually leave them until fall. Then when I pull the stems and remove the stem bulblets, it's much easier to tackle the pesky weed.
Regarding Roundup, it's not that it's only absorbed through the leaves; it can be absorbed (probably) by any living surface. This does include bulbs and bulb scales, and likely roots, too, IF the chemical is not "absorbed" or tied up by something else first. In the case of anything in soil, the glyphosate in Roundup is bound to soil particles so tightly that it cannot be absorbed by living material. Wash a bulb clean and apply Roundup, and it will definitely absorb the chemical. Similarly, coat a living leaf with dust and apply Roundup, and it will absorb less of glyphosate because the dust will be tying up some of the chemical as it is applied. The concept also explains the reasoning for using clean water for application, as opposed to dirty water.
I've always wondered about what is in the bleaching products and ink used in newspaper. I know some use more "environmentally friendly" chemicals, whatever that means....
