Does anyone know where I could buy a container that you fill with water, bring to pressure by hand/foot pump, which then feeds water up a long telescopic lance to water plants in a restaurant several metres tall?
When I lived in a truck, I had a foot pump attached to a 5 gallon water container and I could pump water into the little sink via a tap. I got all this equipment from a caravan supplier, but it was 42 years ago But this technology is bound to still be around.
I assume the roots of the plants are several metres up in the air? Perhaps some pics would help us to advise you.
All you need is a pump and watering lance, buy the lance on amazon and a spray pump, just exchange the heads.Or install a watering system which you can get from commercial suppliers.
They sell them widely for watering hanging baskets.
They do sell realistic artificial flowers/plants now. Have you thought of those?