On my main gardening blog I posted an entry titled When I Collect Purple Coneflower Seeds that has a photo of what a ripe Purple Coneflower seed head looks like. On another of my gardening blogs I posted an image to help identify the Purple Coneflower Seeds. If you are looking for help in identifying the seeds of a Purple Coneflower or want to know when it is time to collect the seeds look over those two entries on my gardening blogs.Once you've learned how to identify a ripe seed head and you remove it from your Purple Coneflower plant you'll notice that the seed head is very hard and sharp. The easiest way to remove the seeds from the seed head is to break the cone by crushing it in your hand. I don't recommend you do this with your bare hands to avoid injury- make sure to wear gloves to do this. I find standard gardening gloves aren't thick enough to keep the spiky head from puncturing your skin so I use standard leather work gloves.
Another way to remove the seeds without injuring yourself is to collect the seed heads after you've had some rain or soaking the seed heads overnight in plain water. When the seed heads are wet you can easily pull the head apart and let the seeds and chaff fall on a paper plate or sheet of newspaper. Make sure to spread them out and let them dry for a couple of days so your seeds don't get moldy if you use these methods.
Coneflowers are easy garden perennials to start from seed. You can sow them directly in your garden or start them in a seed starter you make out of a plastic soda bottle. Your Purple Coneflowers will bloom the year after they germinate.