I wouldn't expect any clematis to look great right now, unless its an evergreen species. I think the yellow balls are slug or snail eggs, I can't quite remember, but they won't be causing your clematis to die - if its one of the varieties, it just hasn't woken up yet.

Thank you so much, Bamboo. I nearly dug it out and disposed of it. I shall now watch it with interest.

Has the clematis been recently bought from a garden center? The yellow balls could be slow-release fertiliser from the compost.

Snail and slug eggs are either clear or milky white. No other pests have eggs big enough to be seen in the soil with the naked eye.

Done a bit of research on yellow eggs in soil - most of the time they are, as already said by others, fertiliser pellets, but if they're less than 1mm, and are quite hard, vine weevil, the eggs of which are initially yellow, turning brown later. In which case, heave 'em out...

I thought they sounded like old slow release fertilizer pellets. I use them quite a bit and have noticed before that they can look like slug eggs.

Well spotted Bulbaholic, a common mistake for slug eggs, the slow release granules can be all the colours of the rainbow, depending on the NPK and other constituents and the time it takes to release their nutrients.

It is a very easy mistake, Jimmy, if you have not come across them before.
Many years ago I bought some alpines from a respected nurseryman, who is also a personal friend, and found some yellow balls in the compost. I worried myself for several days about how I was going to approach him about this when I heard the nurseryman explaining to a third party about how customers mistook these fertiliser balls for pests. I kept my mouth shut and quietly walked away! Lesson learned for me.

I was talking to a Nursery man the other day and he said that the most frequent reason for people returning plants was because of the "pest" eggs in the soil. Also, if you go on other garden sites, as I do, it seems to be the most often asked question too.