Want to know how to grow Puya seeds, well it is not difficult and in our experience they germinate quite readily albeit erratic with some seeds germinating within 14 days others planted at the same time can take upto 35+ days or maybe more up to 2 months in some cases so please be patient if they don't all sprout at once and don't throw any away until you have allowed sufficient time to pass. Normally as a rule however germination happens fairly quickly.
The tiny seeds should be started indoors and sown directly onto the surface of a sandy / cactus compost growing medium, another popular choice is a 50 / 50 mix of seed starting compost and fine grit which can be used when potting on also.
(Another popular alternative is to germinate the seeds in between 2 peices of damp paper towels that have been place and sealed in a clear plastic food baggie and popped in a propagator or on a heat mat under light. If you choose this method it is important to open and reseal the bag once a day to allow in clean air and to stop the paper towels from becoming to dry.)
Very lightly cover the seeds with a fine sprinkle of the medium so that light can still penertrate the surface as these seeds need lots of light to germinate.
To encourage germination it would be ideal to use bottom heat to maintain a soil temperature of 65 - 75F which in our experience is the optimum temperature range to kick start the little seed into life.
Once your seeds have germinated and have several true leaves you can pot them on into individual planters or seedling pots. Remember that the seedlings will be very small and delicate but if cared for and grown correctly they will soon become established and from that point on they can almost take care of themselves.
Keep seedlings in semi-partial shade and away from very hot temperatures.
Once established your Puya will happily bake away in the sun all day long if you wish to put it out in the garden through the spring, summer and early autumn and even though they are rather hardy we still recommend over wintering in a green house or indoors if possible.
Water moderately whenever the soil is about 2/3 dry down at root level and it is important to avoid letting the soil completely dry out, remember damp but not soggy.
Never let the pots sit in a tray of water and keep fairly dry throughout the winter months, unless temperatures are above freezing.
Feed with ordinary vegetable fertilizer at 1/3 of the recommended doseage once a month during the growing season which is from early Spring to mid Autumn.
Some Puya varieties can take several years to produce flower spikes but this time can be reduced dramatically by using a well balanced plant hormone or fertilisers and taking good care of the plant.