I have two plants, which I bought in Amsterdam in the Spring of 2011. They are planted in 12 inch terracotta pots in my glasshouse, in Skerries Ireland. Our garden is only one mile from the sea and we are surrounded by the sea on three sides. The plants were potted in good potting compost, and the drainage hole was covered with shards of pottery. The potting compost is covered with a layer of grit to keep the moisture in.
The plants do not seem to be thriving, and I am wondering if they are in too large of pots? I have just made up a large quantity of fine, well rotted garden compost mixed with equal parts of potting compost and coarse grit. Should I re-pot the plants in smaller plants? They remain in my glasshouse all the time, and in winter are protected with garden fleece. What am I doing wrong??