Grass tree and natives dying

Could anybody offer me any advice on why so many of the native plants I have planted have died. (banksias, grivelias, bottle brushes,and some bushy thing that had purple folage)

The ground is good old WA yellow sand (fill to build the estate), the plants are on retic drippers, surrounded by the cheap mulch that comes when the developer does the landscaping.

Underneath the sand , maybe 200mm deep is old mulch. The type of mulch that is really woody and barky. (not like the surface mulch)

The plants have all done well for a period of time and then die really quickly.
The first lot were from bunnings and the second lot from Lulfitz.

I also had a grasstree, that has died too. It was delivered and planted by the contractor for the estate. It came in a bag, that it looked like it had been in for a while. (not like a rip out of bush and replant on same day type).

It died over a period of about a month. It was never watered from above (ie not onto the "leaves") yet it looks like the centre of it was saturated and decomposing.

I really would like quite a few grass tress, but given their price and the experiance so far im not sure if to do it.

I guess lastly, and hopefully FU MANCHU, can help me if i do try to get some more grass trees am i better off getting once from a company like this www.replants.com.au or from a nursery type situation where they have been nurtured in a pot or bag?

thanks in advance for any feedback

edit: one other thing is it ok to dig up very healthy kangaroo paws that are growing in other areas of my garden, split them with a shovel and transplant into multiple new plants?

I bet i know who the landscaper was from your post best i don't mention them though.

sounds like a water problem.
check the drippers are working.
Very few landscapers are installing the netafim techline AS systems properly. The brown 13mm dripper line I mean. they would have put a gadget in that has a thing that comes up when the system is on so you know it is working. They should have also installed a brown flush valve at the end of each line. That is often missed. There also needs to be a grey vacuum breaker valve that sits around 9-12 inches higer than the highest point of the line on each station. That way when the water shuts off it won't suck back contaminants into the dripper. The flush valve means 2ltrs is washed through each time the system comes on. This keeps the whole system problem free and clean. They also should have installed a disc filter and pressure reducer too. many don't and they block up and stop working and your plants slowly start dying.

there has been a particular landscape developer that keeps getting mentioned in my line of work who is also running black 19mm poly for a few meters and then with miles of 4mm black tube to every plant in the garden. no doubt there recieve a good payment for a system they don't install

cheap mulch buggers

the purple bushy thing would have been possibly an agonis afterdark. the landscapers are eating those up in the new developments.

Have a go at the grass tree again. go see Grass trees australia I think it is on Welshpool road. just drive down the freeway south, onto the grahame farmer freeway which becomes orrong road which turns into welshpool road easy they are on the left near wattle grove.

on the roo paws; get into them. chop the flower stem off though. lots of seasol after the move too and every few weeks after. "don't forget the seasol"

It would be unlikely to be a soil bound fungal issue with all of those plants. one type maybe, but not all.

When they were planted make sure they didn't go in too deep. folks often get a bit keen and dig a deep hole, then back fill with soil around stem area that was exposed to sunlight and air. this then rots the stem and a month or so later it is buggered. like ring barking a tree. mulch is also sometimes heaped up around the stems causing similar issues.

even though they are native they have had a resort lifestyle up till you buy them. water 3-4 times a day, plenty of the right quality food, great soil. then we chuck them into rubbish sand/soil with cheap food and little water. always use some bailies soil improver, biowise or gods gift to gardeners in the area you will plant.

If you got the plants from Bunnings, take them back in a plastic bag and get an exchange voucher. they have a 12 month warranty on the plants except seedlings. george does not I don't think so the stuff you got from him at his caporn street nursery is no good. and the Bunnings people will know if it is their plants or not.

An excellent simple native garden with just roo paws and grass trees is on the road onto the seawall at Mindarie. sounds like you live out that way so would be worth checking out. that will convince you to try grass trees again it's on the right with "big red" roo paws.next weekend would be good with the blessing of the cray fleet so you could pop down and see live music too and go to the brewery there

see if you can along to one of these workshops too
http://www.greatgardens.info/

ring Simon from "swift trees" pruning (0423627911)and see if he has any tree mulch for the garden. He may do if he is working near by. that will keep the plants in tip top shape. might cost a couple of cartons or some money for his fuel but it's worth it and top notch. He does excellent tree lopping too

Thanks for that comprehensive reply FU!!

there certainly isnt any of the bleeding or flush valves that mention. Just a closed loop of 19mm polypipe, with short lenghts of 4mm to get to the plants. I understand the theory behind what you explained with the retic so I may have to get that sorted.

I will definatley get stuckinto my kangaroo paws, they are growing ever so well, absolutley spectacular with flower stems ofer 6 foot high.

I used the Lullfitz down on Thomas Rd as its not to far from my place. (Aubin Grove SOR), and I will use them again. The planting tips wont go astray either

I have some edgin and stuff to do around this garden and then i will get in touch with a more local tree pruner and see if i can score some better mulch on the cheap.

As far as the grass trees go, I will give that mob a go, I know where they are.

Once again thanks for your comprehensive reply

The garden in question just after contractor did his bit. (doesnt have all the extra plants that I added tha died)

Oh if you have the 4mm dripper lines then that is why. just not enough evenly spread water. those don't need the flush or bleed valves. unusual for the landscapers to install a system like that these days.

I would strongly suggest that you look at the netafim 13mm scapeline to retro fit to your garden. Pretty straight forward to do, then cover with mulch once done and all will be good. otherwise handwatering will be needed. Once established the plants will go a little better. The government give you a healthy rebate on installing the netafim scapeline too

I didn't know Lulfitz had a nursery SOR so I thought you were up this end of town (NOR)

all the best with it

just had a look at the pic. It would be dead easy for you to put the netafim stuff in yourself have 19mm poly down the fences and along the front of the lawn so it boarders the garden sides creating a loop. then every 4-500mm plug the 13mm netafim scape line into the black poly with a 19mm-13mm barbed tee. have a flush valve at the far end of the loop from where the water enters the line. have an air bleed up in where the bricks are piled up. bung a filter and pressure reducer (just fits into the line, very easy) where the water enters the line into the garden bed. cover with Mulch. then get a rebate form off the net from the watercorp and bobs ya uncle.

thanks again. ill have a look at setting it up as you explained.