Hi Poppyhans. Litres measure volume, so if a seller offers a plant saying "1 litre", they're telling you the size of the pot the plant is growing in. In this case, the pot is probably about 4 - 5 inches across. 1 litre is about one and three quarters pints. Have a look at things like bottles of squash next time you're shopping - they're often 1 litre.

If you want a rhodo that's about 3 - 4 feet, you're looking for one about 1 metre high. Don't forget that a plant that's "so big" now will be bigger next year and even bigger the year after, so you need to look at the "eventual height" that is often quoted on plant labels, in books and so on. Even these vary quite a bit as sometimes they give the expected height after 5 years, sometimes 10 years.

Look for 'Yak hybrids' - they are bred not to get too large. Check the labels but most of them should only get to about one metre when mature

Thats helpful Andrew, I looked this up and it seems the plants start at 3 litres at about £10 and increase in size and cost. Would 3 litres be a good choice or should it be bigger and costlier? - I remember when I planted 10 it took a long time for them to take off.

It depends on whether you want an instant effect or are prepared to wait. Smaller plants get established quicker and soon 'catch up' with bigger specimens

Thanks