Although they are monocarpic, a well nourished Cardiocrinum will leave a number of offsets of varying size. Some of these will be large enough to have their own leaves in advance of the main plant flowering.
The larger of these can be planted out in the Autumn of the flowering year or the following Spring and will then flower in their second or third year. However, a large offset planted in the Spring may flower the next year. For illustration, in 2007 we had 21 plants flower which produced 144 offsets of various sizes. two-thirds of these could be planted out at once, the remaining ones needed to be grown-on in a nursery bed for a year or two. Only two of the 21 were C. gig. yunnanense and these produced only 7 offsets. One of the 21 was our tallest giganteum to date, measuring 10' 10", (3.3m).
For more detail on the numbers of offsets each year, look at the Offsets page
If offsets are to be used for propagation, it's recommended that the seed pods are cut off as soon as flowering is over to promote growth of the small bulbs.
If it's necessary to store the bulbs for a time, they should be covered in damp leafmold or compost to avoid the roots drying out.
Unlike most bulbs, Cardiocrinum should be planted with their noses just above the surface. Bulbs can be planted out when they're about an inch high and we've found they don't keep well in pots above this size. They're prone to rot off over Winter, presumably due to frost damage and/or excess moisture. Therefore, potted bulbs should be kept in a frost-free environment if possible and only sparsely watered over Winter.
When buying bulbs be sure to ask how old it is or when it's due to flower. Don't buy anything that is more than two years old unless grown from seed and refuse any bulb which is "guaranteed to flower this year"! We once bought a bulb of C. giganteum which was about 4" in diameter, planted it in June only to have it grow to about 4' later that year, then flower without leaving a single offset. As mentioned above, a bulb in its flowering year should be the size of a football and would need at least an 18" pot to contain it and transplanting it would probably effect its flowering.
One problem with propagating from offsets is that your plants will be genetically identical or, at least, very similar and thus all would be equally effected by any pathogen.
All of our original stock came from one plant of each type with the exception of C. cordatum glehnii so we broadened the genetic base by purchasing plants from different sources in 2009 so that we now have at least two separately sourced plants of each type. We might also dabble in a spot of hybridizing, (glehnii x yunnanense?).From seed
Many people find it difficult to germinate Cardiocrinum seed but the point to be remembered is that germination takes time.
If the situation described in ref.1 below applies to all of the Cardiocrinum, the problem seems to be that the genus exhibits MPD, (deep simple morphophysiological dormancy). i.e. the seed embryo is not fully developed when the seed is dispersed and has to grow within the seed before germination takes place.
However, starting in 2009 we sow one pot of seed from each type of plant which flowered in the current year as there is a sugestion that vegetative propagation leads to loss of vigor.  We certainly get fewer offsets from the Cardiocrinum giganteum species than the numbers reported by Mr Cox.
It is reported that, if the seed is sown as soon as it is ripe it should germinate the next year but if seed is stored before being sown then it can take two years to germinate, i.e. two cold periods, but that this time can be reduced by stratification.
We sow the seed as soon as the pod opens in October or November and germination usually starts in the March two years hence. i.e. ~16 months after sewing.
It is reported that it takes the plants seven to nine years to flower when grown from seed. However, our first flowering plants from seed, (Cardiocrinum giganteum yunnanense), occured in 2015; five and a half years after sowing and four years after germination.
For more detail on growning Cardiocrinum from seed, look at the Seed page.By chitting and from flakes
During communication with Far Reaches Farm concerning their cultivar of C. giganteum yunnanense, it transpired that it had been suggested to them that they should propagate this new version via flakes but that no-one knew if this works for Cardiocrinum.
For the details of our experiments with these methods of propagation, look at the Chitting page.