The inner tubes within toilet and kitchen rolls are most useful to use for seeds that either require deep roots or hate to be disturbed when being transplanted. They also make ideal first starter pots for most plants rather than paying for smaller plastic plant pots and having the hassle of storing them later on too. Of course, they are all biodegradable too!
Sweetcorn, peas, beans – mainly the big seeds, can all be grown very easily in these rolls. The plants can be grown from seed within the tubes and transplanted without root disturbance to the soil when the plants are large enough. I have had much success with these with sweetcorn this year and plan on doing the same next year.
Colleagues at work often left me bags on my desk that consisted of loo roll tubes, neighbours collected them for me to the point where I was inundated with cardboard tubes. As I ended up with an abundance I also used them to add to the compost bin as a brown product to balance out the green!