I want to take some cuttings but have only got seed compost at the moment. Is there anything I can add to this to make it suitable for cuttings- I'm thinking of lavender in particular but may do others later.
I think you would be ok with using seed compost as it is, lavender likes a very free draining compost for cutting so it is suggested that you add grit to compost.
Have a look at this page http://tinyurl.com/2jznmt particularly the pics at the bottom of the page.