How harmful is Roundup environmentally?

There are two types of Pesticides, herbicides and insecticides. All herbicides are pesticides.

Roundup is not systemic meaning it is absorbed through the roots. Roundup is absorbed through the leaf of plants. It can not be absorbed through the roots or the stem of plant. That is why it is considered inert when it hits the ground. It can no longer be absorbed by the plants because it is below the level where leaves of plants can touch it.

It is one of the safer pesticides when used according to instructions. As with any pesticide, used improperly and it can cause serious damage to the environment.

To add to Metalpa's answer, yes it is systemic within the plants it contacts. So of course you would not use it on or around vegetables and fruits or other plants you don't want injured or might be eating. When I mentioned I sprayed Roundup along the edges of my vegetable garden, the state weed specialist visibly blanched. So I no longer do that.

When used correctly, it is perfectly safe. (Don't wear shorts when spraying it as the blow off onto your legs can be painful) I would not put the dead or dying weeds in the compost pile. There's just no way to adequately determine when the product breaks down in all situations. In theory it might transfer through the compost.........personally I would be surprised, but we have to cover all bases.

A pesticide is a general term for a product used to kill pests: weeds, insects, rodents (redenticide), mites (miticide), fungus (fungicides), etc.

It is against the law to use any pesticide in any way that is not recommended on its label.

The pesticide component of Round Up is quickly bound to soil particles and is relatively harmless in a diluted concentration, it degrades over a few months as soil microorganisms break down the chemical so it does not persist in the environment.

It should not be used were it will contaminate water sources, since it has a longer life in water and the filler ingredients can be toxic to fish.

Subclasses of pesticides include: herbicides, insecticides, fungicides, rodenticides, pediculicides, and biocides(which include...fungicides, herbicides, insecticides, algicides, molluscicides, miticides and rodenticides.)

past that.... RoundUp.... you need to get info from BOTH sides of this issue.... there are folks who are citing all kinds of studies that say it's one of the worst things you can have in your array of pesticides..... then there's the other side that claims that if not for it, we'd not get happy crops and be able to feed the world.....

there's reports of plants becoming immune to it.... and then there's the Genetically Modified plants that can ignore it..... but that means it's sprayed on food we eat, that is modified somehow.... it's all in what you're ready to accept in and on your food.....

but .... in the home garden, care MUST be taken with its use.... and you should be well informed about it, pros and cons, before you decide to use it.....

I'm by no means an 'organic' gardener', but there's no way I'd use it around food plants, and for the record, not anywhere else, either.....

get into Google and Yahoo's sources and read for yourself..... and read the good and the bad before you decide.....

Google it and you will find different answer to what everyone thinks..look again !

EDIT meanolmaw has the links to what i was on about i had bad problem with a dog i had who chewed the grass i had treated with this grass was dry but was not harmless i have hated the product ever since.

Round-up disappears entirely within 24 hrs.