I've got some information to help you.

Dirr, Michael A and Heuser, Charles, Jr. ÂThe Reference Manual of Woody Plant Propagation: From Seed to Tissue CultureÂ; (Second Edition 2006); Varsity Press, Inc. ISBN: 0942375092 or ISBN: 13: 978-0-942375-09-1

"Cystis scoparius: July-August cuttings, 800 ppm IBA-solution or tale, well drained medium (root systems are often brittle), mist, root in the 70-90% range. Untreated cuttings of C. scoparius 'Dragonlady' rooted 35%; 70% with 8000 ppm IBA-talc. Cuttings can be rooted in greenhouse or outside beds. Rooting takes 4 to 5 weeks. Plants should be grown in continers since field grown material does not transplant easily."

My advice is to use "Clonex" or "Clonex Red." Clonex Red is a newer product but both should be sufficient. I just don't prefer talc rooting products.

Something else that's important in my opinion is a root-gel dip of Mycchoraize (sp?). I buy mine from Treehaven Evergreen Nursery/Hilltop Tree Farms. Someone on the Conifers Forum labled me as "snake oil" dummy. You should see the roots formed with this product alone when used for cutting propagation. A dip in this gel afterwards when you have your rooted plants, and either (potted) or into temporary nursery beds, is the difference between losing plants, and not. I've seen such success...

I have yet to use both as a single application so I cannot answer that but something tells me a dip in Clonex followed with a dip in that gel might be advantageous...

Use a 1" or 1/2" heel of semi-hardwood mainly and full heels of hardwood would also be acceptable for this time period. You should also for general purposes, stick, three softwood cuttings. Thuja occ. 'Spiralis' I found roots superior as softwoods during summer. Opposite of anything you would ever think......... Your mixture seems very good.

Dax