I have about half an acre that i'm turning from what was
cattle and sheep grazing into fruit
trees and bushes on a slope about half was rushes I used this attached to a good high powered strimmer
INDUSTRIAL GRADE 60 TOOTH CARBIDE BRUSH CUTTER WHIPPER METAL BLADE fits a standard shoe you take off the strimmer line feeder
https://www.aliexpress.com/item/1005002142626065.html?spm=a2g0s.9042311.0.0.27424c4dGjIKw0
Cuts though them like butter lasted me for years careful of stones tough as it can take off the carbide chips on the blade
at least one cut in summer BEFORE they seed as they produce thousands per plant the more you cut the more they will be wakened.
Then another in winter when there is a big hard freeze water them with cold water from a watering can after you have cut them to fill up the inner space in the reed this freezes and expands splits the reed to the
roots and kills the active growing shoots.
Then what your left with is the solid clump (
root ball) and when its been very damp use the attachment to slice into it vertically like cutting up a cake then use a sharp spade to open up the segments and they will just pop out and dig it out. Fill the divert when you have taken out the root ball with compost and plant grass seed to outgrow the few reeds that will come back.
The man problem are the seeds they can survive in the wet soil for years and will keep coming back as little sprouts so you have too keep up the two cut regime but eventually they will just decrease and decrease
The cut reed make perfect mulch as good as
straw and excellent composting materiel
Good drainage, watch the soil ph and apply gyp rock to aid compaction and aerate the soil but that has to be done anyway with this kind of land took me 3 years now its sweet