I have large clumps of various species of Cypripedium in among the Meconopsis. These were always bought as small plants and over the years can form magnificent clumps but it is a slow process. Many of the Dactylorhiza orchids do grow from seed in the garden in association with micorhiza and usually flowers appear after three or four years underground as a single large flower spike. This image is of the native slipper orchid Cypripedium calceolus which was dug up from the wild until only a handful of plants survived. Things have changed now. Orchid seeds  do not carry food reserves but in the case of the lovely species of Cypripediums people have learnt how to grow them in tissue culture or from seeds in culture. They are therefore now widely available though no doubt expensive.