If I combine soil improver with compost do I need to add fertiliser and water retaining gel?

What are you growing?

Welcome!
And are you talking in the ground, or in pots?
Where more generally are you located? (Bucks County, PA, USA, or ?)

Are you talking about the Scotts product? In that case know it's just a mixture of volcanic ash, char and Fuller's earth. Nothing earthshattering but Scotts's marketing here.

I am also curious to know why you want to use "water retaining gel".

Kevalsha said:What are you growing?

Bamboo in a pot.

sallyg said:Welcome!
And are you talking in the ground, or in pots?
Where more generally are you located? (Bucks County, PA, USA, or ?)

I'm planting a bamboo in a pot-Bucks, UK.

ElPolloDiablo said:Are you talking about the Scotts product? In that case know it's just a mixture of volcanic ash, char and Fuller's earth. Nothing earthshattering but Scotts's marketing here.

I am also curious to know why you want to use "water retaining gel".

I am planting a bamboo in a pot and I understand they must not dry out.