Planting of Thymus 'Pink Chintz' and Sagina subulata (Irish Moss)

Good morning!

I bought some Thymus 'Pink Chintz' and Sagina subulata (Irish Moss) plants over the weekend and my plan is to put them in-between the pavers we have. I plan to divide the plants into 4 so they will fit between the slabs.

At the moment it's just 6mm gravel between the slabs (see photo) do I need to pop some soil in there too or is planting direct in gravel OK?

Many thanks,

E

 

Thyme wants some soil I think. Mine is fully in soil.