Hi Leslie,
I'm currently renting in Helensville too, and have been a local in the area before that for about 20 odd years.
Which bit of HLV are you in? Rautawhiri looking down to the road, Garfield looking down townwards, or somewhere else?
Buttercup is a complete arse to get rid of, particularly in heavy clay.
I would suggest raised beds *with beams underneath to raise them clear of the soil* this way they are theoretically transportable, at least in summer when the soil is relatively dry. 1.2mx.6m is a good size (you can buy 1.2m fence palings at Mitre 10) and make them 2 boards high.
There is a guy out past Parakai on the LHS of the long flat just past were Nestlebrae exotics used to be who sells 2nd hand 44Gal plastic drums - i cut those in half and drill holes for drainage, and some at the top to tie on rope handles, and use them as oversize plant pots to grow fruit trees (plus some herb/flower understory) in until i can buy my own place.
If you have good boggy acidic soil, consider digging in some pine needles and coarse sand, and then planting blueberries.
