It makes negligible seeds, very few and mainly empty pods which could only hold 1-2 seeds. It is possible to root cuttings if they have some roots. It isn't aggressive enough to hold it's own with annual weeds or perennial grasses. I had to eliminate those and mulch heavily then plant well rooted plants on 4 ft. spacing.during the rainy season.
I did dig some plants at a friend's house and got them to root, but I also bought 200 rooted plugs in 2" cells and put them into 1 gallon pots. The best way to propagate is by leading the runners from established pots into fresh soil filled pots.
Once I had a long line of established pots I could cut the network of post loose and keep adding fresh pots on either side of the line every month once they had roots down to the bottom of the pots. That way the multiplication became exponential and eventually I had 1400 pots full. Planting was simple I used a two-handed hand post hole digger and dropped the pots in and watered once.
Occasionally I pass through the area and hand pull scattered weeds to prevent them from beginning to run or set seed.
This plant is very tough and the only thing which seems to slow it down is shade and standing water for too long. It won't grow into deep shade or thrive there. During a time of heavy rain when some areas got flooded it seemed to lose some of the leaflets but once the area dried up it came back better than before.
This was the propagation area:
This is showing how I led runners from pot to pot. They root at every node even just laying on soil but it was better to dip the runner into soil leaving the tip exposed. When actively growing they send multiple runners out of each pot so you can easily put fresh pots on either side of an established pot. Now that I have established ground cover I can root directly out in the field.
This video doesn't focus on the strigillosa but you can see it has climbed up and into the pineapple bed. I had established some perennial peanut there but the mimosa is outcompeting it.
https://www.youtube.com/watch?v=y20U4UJFV-Ufactsheet:
http://blogs.ifas.ufl.edu/nassauco/files/2017/05/Mimosa.pdf