Interesting idea slopfrog. I immediately thought, oh no, that surely will attack the tubers but after reading up on the product, I don't think so. The only thing I saw of concern was the description of half life. Purportedly 3 to 141 days.

I'd be interested to hear what others think.

Darren

It should only affect the plants that you sprayed the leaves of. It won't travel through the soil to other plants. IMO.

As Zackey said, my understanding of Round-Up is that it is foliar in application. So as long as the Caladiums don't have any leaves above the ground, they should be protected. The Round-Up will break down into its harmless components by the time it reaches your tubers, so they should be safe. If you go this route, keep us posted in the spring on whether or not the Caladiums come back. (Though I believe they will)

Why not just cover the top of the soil with newspaper, more mulch, clippings, plastic, anything but that awful stuff in lieu of chancing it? The Roundup will break down, but nobody can give you an actual answer as to when. And who is to say that any rains won't wash it over to other plants?

At least with the paper, mulch, clippings, leaves, etc, you're also improving the soil..

Because its the front of my house and I don't want it to look bad. :)

The only one of those products that wouldn't look bad is more mulch, but that's just going to make it harder for my caladiums to pop back up, and is just going to give more stuff for the weeds to grow in.

Layer newspaper over the spot and then put mulch on top of the newspaper. That way the newspaper can suffocate the weeds and the mulch hides it from view.

As stated above, Round-up will definitely not hurt non-green plant tissue. Round-up is totally safe to spray over planted bulbs, or seeds. Round-up is also safe to spray on the bark of larger trees and woody shrubs.

The trick is, you just don't want to get it on green tissue or tissues soft enough for it to be absorbed. Round-up will NOT kill plants by run-off. You can get to the base of a plant you want to keep, as long as you keep the spray off the plant. I have weeded my veggie gardens for 15 years using roundup and use it constantly today.

But, you can ONLY use Round-Up for this, no other weed killers are safe to use in this manner. Also, round-up has no residual weed killing effects. So, it only kills what the spray hits.

I have the same question. Responses make complete sense. I've got pokeweed and Japanese knotweed I'm battling with. The grass underneath is very very dormant and dry. And muscledbear, let us know what cancer diagnosis you finally get.

I have the same problem with Amaryllis bulbs. Weeds take over, when I try to pull them up, some of the bulbs come up. I can't use Round-up because the bulbs do not lose their leaves. Its a nightmare. I have a large bed of Reds in the back of the house and I love them. Moving from NY, I call them my Florida tulips because they flower in early spring.

I have some summer flowering Amaryllis in the front beds and they get covered with weeds. I have to hand pull which also pulls out the bulbs.

My problem is this grass which sends runners into the beds and when you try to pull it up it is like a long cord which runs under the bulbs. I can't spray Round-up because the bulbs have large, thick leaves.

Jane