Grow connects to Pardot via an API connection. Pardot only offers the API and functionality needed on their Pro and Ultimate plans.
In order to access Pardot in Grow, your organization must be on the Pro plan or the Ultimate plan in Pardot.
According to Pardot’s documentation, the Professional edition accounts have a limit of 25k calls per day, and Ultimate edition accounts have a limit of 100k calls per day.
You can also find additional information on Pardot’s pricing page.
Questions? Email us at firstname.lastname@example.org or chat in on the site.