need advice on cutting back plants please....

[startingagain]

my ex built a small walled area in the garden which he covered in that plastic stuff then covered that with mulch or something like that. Anyway, then he planted, kind of look after themselves kind of plants, grasses, sort of palmy looking things, stuff that comes back each year and doesn't need a lot of looking after.

I obviously need to look after them myself now and i am not sure what to do as the plants have got really bit, theres a bamboo there aswell.

Can i just chop them all down abit (now?) and with the bigger plants do i need to sort of dig up half of them to make them smaller?
Just to give you an idea, there is also one of those black grass things, but thats still small so that ones not really a problem!

Sorry to ramble but i haven't got a clue!

[ShellingPeas]

I don't cut back grasses or bamboos until the spring - the top growth protects the crown of the plant over the winter so I wouldn't do anything to these yet.

If the grasses are getting very big you can dig them up in the spring and then divide/split them into smaller pieces and replant the pieces you want to keep but don't do it now as it's better to divide grasses in the spring, not the winter.

Do you have any idea what type of bamboo it is? Some are very spreading and can be invasive while other make clumps. If it's clump forming you can cut out unwanted canes in the spring which will leave space for the new canes to come through. If it's a spreading bamboo you will need to make sure the underground runners are kept under control either by pulling them up or by putting a barrier around the plant.

The black grass thing I'm assuming is this stuff - this needs virtually no maintenance at all, so just leave it if it's not crowding out any other plants.

[startingagain]

Yes that is the black grass.

Thanks for your advice will be following it!