Yes, you could if you’re sure about the pipe being defunct. However, the hole looks too close to the fence to give the Pittosporum sufficient space. How far away is it?

never heard of that kind of pipe being used for irrigation ... it would be ridiculous overkill.. and very expensive for the application ....

have you ever called miss dig... to find out what the pipe is ... and to confirm your assumptions ....

im not sure i might not just backfill to the pipe level.. and just plant on top of it .. and in fact.. with your rather clayish soil... you might be better off ...

have you ever perked your soil ... will water drain out of that polished side hole???

https://duckduckgo.com/?q=perked+garden+soil&t=ffcm&ia=web

ken

https://sites.google.com/site/tnarboretum/Home/planting-a-tree-or-shrub

The center of the hole is about 2 ft from the fence..

Galvanized metal piping is very common with older, inground irrigation systems, especially in homes built more than 30 years ago. But because it is no longer the most efficient, long lasting or economical means of water delivery, it has been replaced with PVC or other synthetic materials.

As long as you are sure the pipe is nonfunctional, you could certainly manipulate the rootball to accommodate if you cannot remove. But floral's comment remains valid. Make sure you are allowing sufficient room for the plant to grow to size without interference from the fence or other structure.

Yes unfortunately in the old times metal pipes were popular in my area for sprinklers. Nowadays when I try to find someone to fix a minor issue, almost all landscapers turned me away, said they don't maintain galvanized pipe sprinklers anymore and charges 10k+ to replace to PVC...

The problem with metal irrigation piping is that corrosion and chemical deposits accumulate and tend to restrict water flow. After 15 years, capacity is typically reduced by as much as 50%, increases as time continues and will be a source of ongoing maintenance and repair issues. Investing in an upgraded system will eventually turn out to be a money saver both in terms of plant health and reduced or eliminated repair bills.

Thank you for your replies. Yes, now I use drip for my garden beds now and they look much happier now. Will try to reduce the size of the lawn is the next project :)