Question
I am new at this and I would like to find out how to locate and harvest the seeds from my Hydrangea bush, and when to look for them.
it's name is Hydrangea arborescens 'Annabelle'
I call it a snowball bush,I live just outside the south side of chicago Il.Let me thank you for your help in advance, thank you.  

Answer
Ginger, before attempting to harvest seed, make sure that you are growing open-pollinated varieties. Most varieties sold through nurseries are hybrids. Propagation from hybrids never breed true to the parent plant. You will still get a viable plant from the seed, it just will have some different characteristics.

In the case of Annabelle, I do believe this is a hybrid. Therefore, you may want to consider taking a cutting and propagating the plant through this method. If however, you would like to still harvest the seed, simply allow one or more of the flowers to fade until fully darkened. At that time, cut the spent flower below the swollen pod. Allow the pod to dry for at least five days. You can then gently remove the papery covering. The seeds can then be easily removed and stored in a cool, dry place until you are ready to sow the seeds next year.

If you choose to propagate with cuttings, cut a tender shoot that is at least six inches long. Remove the lower sets of leaves. Dip the cutting in a rooting compound. You can purchase this product at any garden center. Stick the cutting one inch into a good potting mix. Be sure to thoroughly wet the soil prior to planting.

Finally, cover the pot with a clear piece of lightweight plastic. Place the pot in indirect sunlight on an east window seal or under fluorescent lighting. After two weeks, check to see if the plant has rooted by slightly pulling on the stem. If you feel resistance, remove the plastic covering and be sure to keep the soil moist. The plant should then be treated as any other seedling.

Good luck, and please write again if I can ever be of assistance.

Regards,

Mike