Chlorine (in form of chloride ion) is an essential micronutrient for plants; is a cofactor for photosynthesis, among other things. So, that part of city water may actually be useful.

If people can take it, your roses shouldn't have a problem with it.

If you are really concerned you can always store the water in a tank or even watering can for aabout 24h before use to let it evaporate but I really don't think there's enough chlorine to cause a problem.

Chlorine is much more likely to harm houseplants than roses, given that they receive ONLY chlorinated water, and the soil volume is restricted. Even then, you're more likely to kill a houseplant with your actual watering regimen, i.e. over- or under- watering, than with chlorine burns, lol. I've heard that a few houseplants are ultra sensitive to chlorine, but at the moment I can't think of which ones.

Chlorine is highly reactive, the reason that it's an effective killer of bacteria, germs and viruses. And the amount in tap water is relatively low. There's *just* enough to kill those germs, and once that chlorine molecule binds to a germ/virus/organic matter (yeah....THAT organic matter), etc, it's harmless, as it becomes non-reactive. As mentioned above, humans DO drink it without harm. But that very reactivity is what prevents it from being much of a danger to outdoor plants. As soon as chlorine molecules come in contact with soil, they bind to soil particles, bacteria, organic matter, some minerals, and just any substance with a stray electron running around. So all of the chlorine is actually bound up in the first couple of inches of soil. If you're using mulch, the chlorine may never even reach the soil. Drip systems might be slightly more problematic, as they concentrate all of the water in a small area. But even then, I'd think any adverse effects would be minimal, especially here in the east (and especially FL!) where we get considerable rain. Though plants don't seem to be harmed by normal chlorine levels, there have been studies done that show the bacteria and mycorrhizal level was adversely affected by chlorinated water, but that the effect was very short term, and populations rebounded quickly...as in a couple of days.

The one caveat I would make is to never, ever use pool water to water anything. The concentrations of chlorine are MUCH, MUCH higher in a pool than in drinking water. Mature trees have been damaged and even killed when a pool was emptied onto their roots. If you ever need to empty your pool into your lawn, stop treating the water for a few days beforehand. Chlorine evaporates quickly when suspended in water, and within a few days to a week will reach drinking water levels, and it will be safe to dump on your lawn/tree roots.

As an off-topic aside, if you're afraid of watering houseplants with chlorinated water, just let your water sit for 24 hours before watering your plants. And you should NEVER add tap water directly to an aquarium. Fish are highly sensitive to chlorine. Remember, they are *breathing* that water. The contents of our mouth and stomach deactivate chlorine. Not so for a fish's gills. So let the water sit for a day before adding it to the aquarium. Your fish will thank you (by not dying).

I have always wonder this myself.... I live in South Florida and have sand.... but no matter how much organic material I put down I get back sand. I have to water daily and I think the chlorine kills my good soil bugs.... otherwise I can not account for why my soil looks dead and not alive with microisms.... too bad the local university does not have an ag department that could study this for me.

Unless you're soaking your soil in concentrated chlorine, I doubt it. Chlorine dissipates pretty quickly when exposed to the air so the low levels your water contains likely does little to your soil. Of course your soil goes back to sand quickly. The hotter it is, with sufficient nitrogen and soil moisture, the faster the soil bacteria and fungi "digest" the organics. If your organics disappear quickly it means you have LOTS of biological activity going on "eating and digesting" all of that material. Keep feeding it! If there were issues where the chlorine was damaging or destroying your soil organisms, that organic material wouldn't be digesting out so quickly.

roseseek that is good to know. I guess in my older age I was confused. I thought it was rocks break down to sand and sand breaks down into dirt and the microisms turn the dirt into soil..... So I kept thinking that the leaf mulch should be turning into good soil and not into sand.

I don't think sand really breaks down very easily. But adding organic material should make a difference eventually.

I work in drinking water. In your municipal water, there is usually anywhere from 0.2 - 2.0 mg/L….the further from the treatment plant you are, the lower the residual. That’s because hypochlorite degrades over time. If you are closer to the supply source you can fill up a few jugs and let it sit for a day or two before watering your plants with it.

@sharon2079 the organic materials don't break down into sand. Yes, rocks weather and are physically reduced to sand and other particles such as clay, depending upon their chemical make up. Anything organic is digested by the soil flora and fauna into their chemical nutrients, some of which are absorbed by plant roots, others are washed deeper and deeper into the earth by the movement of water. Think nitrogen being flushed through the soil into a lake or river as an example. Some of the rock in the soil is reduced to smaller particles or even fully eroded by the acids in the water (including the water itself), but, in general, if you have clay soil, once the organic material is fully digested away, you are left with clay. If you have sand, once it's digested away, you're left with sand. That's why, just like Ma Nature, we have to constantly apply more organics to the surface of our gardens so the soil flora and fauna keep eating it, to keep feeding the plants.