By Tonyl
Northumberland,
United Kingdom 
this maybe a stupid question but here goes, How much is a good water? yesterday I asked about why my Lupins leaves were drooping and was advised to give it a good watering, so last night i gave it what i thought was a good drink of about a litre. This morning it had really perked up and was all chuffed with myself, Ive just had another look at them and they are starting to droop again.Did I not give them enough water or is it just the hot weather thats causing it?
6 Jun, 2016
Answers
A litre is not really a good soak, 5 litres would be better.
6 Jun, 2016
Agree with Owdboggy - five litres minimum.
6 Jun, 2016
I would give about 12-15 liters, but that might just be my dry climate.
6 Jun, 2016
Any more than five litres is a hose trickling at the base for an hour instead as far as I'm concerned, Tug!
6 Jun, 2016
Well, that's how we have to water, here! :) I was guesstimating, again.
6 Jun, 2016
Try placing a thick layer of mulch around them to help retain moisture and shade the roots....then give them a good watering.
6 Jun, 2016
Mulching is good for practically all plants in all climates. Do remember to not pile the mulch around the actual base of the plant, though--give it 10-15 cm room to breathe, and more for shrubs and trees.
7 Jun, 2016
As already said, one litre is simply not enough - it's barely enough to water a small pot. All one litre will do is wet the top layer of the soil, which will then quickly dry out again in the current very warm weather. You need to get plenty of water down to the roots.
7 Jun, 2016
And there's no such thing as a stupid question - if you don't know the answer its sensible to ask. Nobody knows everything.
7 Jun, 2016
Steragram's right, it's not a stupid question - in my experience, the thing people most often get wrong is watering, it's definitely top of the list of misguided understanding.
7 Jun, 2016
Thank you for all your answers, I was scared I may over water (if that's even a thing) gave it a real soaking last night and it's looking much healthier.
7 Jun, 2016
Overwatering is next to impossible outdoors in the ground. It is possible to overwater plants in pots, if they have a tray at the bottom, or an outer pot, without drainage holes, but a pot with unconstrained drainage at the bottom should be fine.
7 Jun, 2016
One thing I have been known to do, is to make a ridge of soil around a plant so that when watering, the water does not run away into the border. Then when it has soaked in where I want it, mulch..
7 Jun, 2016
If it perked up with watering give it some more. It all depends on how dry your ground is. A really good soak every few days (if needed) is better than a smaller amount every day. You need to give it enough to wet the soil to the roots.
6 Jun, 2016