[Elcie]

I go to my allotment everyday as I have my lovely chickens there.  I water when needed, regularly for the pots, less so for the beds, with the mains water on site.  But it seems to me that the plants really perk up when they have some rain.  When I went there today I could really notice a difference.  I think!  Am I going mad or do plants much prefer rain water to being watered through a watering can with mains water?

[solway cropper]

Do you have particularly horrid mains water where you are?

It might be that during a shower the humidity is higher which the plants appreciate and which you won't get with a watering can.

[Jabberwock]

I reckon I must be mad too then because I was just saying this to my hubby earlier this evening 
We have had a full days rain here today (much needed) and when I went on my evening rounds I swear everything has grown an inch since this morning, our drinking water is actually very nice here (compared to other places I've lived) but my plants definitely seem to perk up after a good downpour and Solway Cropper I think you are on to something there because it has been very humid all day.

[GrannieAnnie]

Rain water is softer than mains water and doesn't have all the additives in, so you are probably right, plants prefer rain water! 

[Zippy]

I find this too. I water my seedlings with tap water and with rainwater from the butt, but when they are out in a rain shower they really pick up and put on amazing growth. I wonder what it is, but i'm glad it is!

[Trillium]

In the growing season, mains water also tends to be colder which plants don't appreciate.

[fatcat1955]

Could it be that a 5 minute shower waters the plants far more than you could do by hand?

[Babstreefern]

My veg have certainly shot up.  Also, I have carnevorous plants in a raised bed, and you never water them with tap water, always rain water.

[SarahB]

Could it be that a 5 minute shower waters the plants far more than you could do by hand?

I think that's pretty much it.  Light showers don't seem to do a lot (other than perhaps cooling the plants down), but half an hour of rainfall drops a good deal of water, and it drops it over the entire plot at once.

[Jemimapuddleduck]

Rainwater must be more natural than tap water with all its various additives.  Our tap water up here is pretty good, but we always water the garden with rainwater....seems better somehow, and the veggies love it!

[Wild Pony]

Its the chlorine I guess, rain water never saw a treatment works until it falls in it 

[mumofstig]

could it be that rain is slightly softer (more acidic?) our tap water is very hard and chalky.
I often wonder if that's why some pot grown seedlings fail, cos they don't like the tap water 

[butterfly blue]

I must be mad too then , after the last few days of rain my raised beds have gone mad leaves everywhere, spud leaves are like triffids too!

[Jakell]

Its the chlorine I guess, rain water never saw a treatment works until it falls in it 

 Even though I hear about the unwholesomeness of tap-water, I have come to wonder about the level of this I have observed that algae seems to form just as quickly in a butt of mains water as it does in rain water. You would think that that algae would be slowed down if the water was less healthy.

 Regarding the effect of rain. Usually when it rains, it is over a longer period than when you water, also there is less sun and more  water vapour in the air, this would mean the foliage of the plant would also absorb water and not just the roots

[sclarke624]

I've noticed this as well and was only saying it yesterday to other half.  It gives them a real boost, they look green healthy and really perky.  I water everyday as well as mine are in the garden, and I tend to overwater a bit.