You can use the old compost to improve your gardensoil but use it well away from where you intend to grow tomatoes or potatoes.
The Sun (2008)
If your gardensoil is particularly acidic or alkaline you can have a contrasting or neutral soil to increase your range of plants.
Times, Sunday Times (2016)
Plant it firmly in a large pot full of moist sand or gardensoil.
The Sun (2013)
Seedry soil
Definition of 'garden'
garden
(gɑːʳdən)Explore 'garden' in the dictionary
countable noun
In British English, a garden is a piece of land next to a house, with flowers, vegetables, other plants, and often grass. In American English, the usual word is yard, and a garden refers only to land which is used for growing flowers and vegetables.