The players reported back for pre-season training last night and were told that the 29-year-old would be on board as the club aim to notch up their fifth promotion in six years.
The arrival of Blackwood – currently on holiday – is a massive boost for the Hawthornden men as he is an experienced campaigner who has played for the likes of Melrose and Rotherham Titans in the past.
He can play a number of positions in the backline and has previously played with the likes of new captain Gavin Brown and Bernie Hennessey at Watsonians.
Lasswade president Ian Barr said: “We are delighted that Jamie will be playing at Lasswade during the coming season. He is another experienced player to add in to the mix and we will need that in what we know will be a really testing division. As mentioned, Gavin Brown has taken over as first-team captain from prop Mark Billingham.”