In article 3e9db03e-5952-4caa-bc3b-
,
says...
Last year took some cuttings of a yellow Argyranthemum, (Jamaica
Sunrise), but when they flowered they were all white. I think that
Argyranthemums are Margeurites which are naturally white. Do the
nurserymen add someting to the feed or otherwise treat the original
white form of the plant?

Not all margeurites are white some are yellow, and as far as I am aware
nobody does anything to them to change their colour although treating
with growth retadants can sometimes happen.
When did these white flowers occur? as the flowers in winter on pink and
yellow varieties can appear white but the same plants will have the
correct flower colour later in the warmer part of the year.
--
Charlie Pridham, Gardening in Cornwall
www.roselandhouse.co.uk
Holders of national collections of Clematis viticella cultivars and
Lapageria rosea