camellia buds not opening

Hi Karol ~
I'm not sure what you've been advised already, but you can buy liquid in bottles from B&Q and other outlets which contains iron, which you add diluted to the soil in your pot and this should help stop the yellowing of the leaves on your camellia.

Also, make sure the Camellia is well-watered during the summer months, as I've heard this can help produce the flowers the following spring.

I hope this helps. :o)

Camellia's also need ericaeceous soil. I bought a small bag and just lay some on top of the existing stuff and watered well. It seems to have improved it's health. Also, only water with rainwater if you can, it prefers that too! Such a fussy plant but well worth the effort!