Camellia flowers dropping

Hi I am new to this and new to my garden!!  There are two beautiful camellias in our garden just coming into flower.  They are 3metres tall and approx 1metre  plus wide so very well established.  My problem is that the flowers, whilst beautiful, last for such a short time before falling off.  Why is this happening to the point that we have to rake the flowers from the bottom of the plant every other day??  Look forward to your thoughts

Camellias are very fussy plants and even with the advice of my local nusery, I struggle. Site is most important they dont like sun all day or wind. Drainage has to be good and mulch with ericaceous compost. They also aint fully hardy and frost can be an issue. Soil needs to be on the acidic side 5.5-6.5ph. Its hard to pin point whats causing it but on your next visit to your local grden centre ask, they a usually very helpful

Kind Regards

steve