The private nursery firm has tapped into the funding to acquire the four-strong Oranges & Lemons group in Dundee, taking its portfolio to 36 across Scotland and the north-west of England.
And founder Graeme Scott expects that number to increase by 40 by the end of the year, noting the group should comfortably hit 60 given the strength of the management team.
Bertram currently has two sites already in development in Glasgow, one in Edinburgh and one in Aberdeen.
The latest acquisitions restore a trend which has seen Bertram grow through acquisitions since it was founded in 2000, starting with the purchase of a former nursing home in Edinburgh and its conversion into a 100-place nursery.
That was followed by the addition of nurseries in Aberdeen in 2002 and Glasgow in 2006, before the acquisition of Happipots swelled its number by 12 in central Scotland in 2007. Its biggest deal to date came with the Holyrood Nursery Group, which gave it 15 sites in the north-west of England.
Mr Scott cited Santander's appetite for backing the SME (small and medium-sized businesses) as crucial to securing the latest additions.
He said: "They have a very good team, they tend to have experts so you are not dealing with general practitioner bankers, you are dealing with sector experts.
"The people we deal with purely deal with the care sector, so they understand your business and they understand the risk or lack of risk on the deals that you are doing."
The deal secured by Bertram includes £1.5 m illion growth capital facility, provided on a cash flow basis. Made available under the bank's Breakthrough programme, it is designed to help fast-growing small businesses accelerate their growth potential.
Some of the funding secured by Bertram will be used to expand its existing sites.
Explaining that staff numbers are on track to rise to nearly 900, Mr Scott said access to capital for SMEs in Scotland was improving, but added: "At the end of the day, some banks have better balance sheets than others, and that's just a fact of life.
"And businesses just have to lend according to what is right for them. Santander just seem to be prepared to risk more than others."