I would say probably not, maybe when watering add some liquid fertiliser. Are they in pots or bags or in the ground? Be careful not to over water if in bags.

Do not feed at all Blencowe just earth up and water regularly if it doesn't rain.

Pam potatoes do not need to be 'fed'.

if the plants are looking a bit under colour use a seaweed based foliar spray....maxicrop for example.

We've never once 'fed' our potatoes with anything - if you prepare the soil properly and use plenty of organic matter it isn't necessary. If the foliage is looking yellowish I'd think it was one of two things, lack of light - potatoes need to be grown in full sun to do well, lack of water - again potatoes need a lot of water to grow well. Probably one of the reasons they do so well in Scotland.

As you say, soil preparation is vital whatever you grow.
Someone growing potatoes for the first time probably wouldn't do so, and growing in compost in containers has lots of problems of it's own, especially as you say, watering.
That's where foliar sprays can come in useful. Leaves absorb nutrients well and i spray the whole garden, vegetables and flowers, at least three times to give everything a bit of a boost.

thanks to everyone for their tips,the potatoes look very healthy,i will follow the hints givenand look forward to harvesting them

God luck!

thanks everyone for the good advice csssssant wait for the results its quite exciting as i have never grown pots before