Landscaping Pros: Do you charge clients for time purchasing materials, take a markup, or both?

I charge by the hour (same rate) from when I leave to purchase plants, to the time I arrive back to the site with them. If I have to purchase and transport larger materials I charge a bit extra.

Landscaping and most home improvements fall into a similar category. The contractor should know where to get the materials needed and the mark up should be included in the original quotation. An Established home improver will have a list of suppliers and costs for most if not all materials and they would therefore have 99% of the job on the quotation. The only extras would come from add on's that the client asks for but again, the home improver should be able to quote before making the new add on improvement. Very few clients will accept a job without first getting a quotation.

In my business I figure time it takes to pick up the material. I may markup if I find a good deal on supplies that I know the average consumer couldn't get.