I am on very heavy clay, so decided to dig out where the new plants etc are going and plant in a mixture of compost and perlite.
This allows me a much wider range of plants.
Perlite is £8.10 for 10 litres at B&Q, got 300 litres for £60 delivered tomorrow.
It was from a hydroponics company, so will set off the alarm bells.
Well worth comparing prices.