Bass Coast Post
  • Home
    • Recent articles
  • News
    • Point of view
    • View from the chamber
  • Writers
    • Anne Davie
    • Anne Heath Mennell
    • Bob Middleton
    • Carolyn Landon
    • Catherine Watson
    • Christine Grayden
    • Dick Wettenhall
    • Ed Thexton
    • Etsuko Yasunaga
    • Frank Coldebella
    • Gayle Marien
    • Geoff Ellis
    • Gill Heal
    • Harry Freeman
    • Ian Burns
    • Joan Woods
    • John Coldebella
    • Julie Paterson
    • Julie Statkus
    • Kit Sleeman
    • Laura Brearley >
      • Coastal Connections
    • Lauren Burns
    • Liane Arno
    • Linda Cuttriss
    • Linda Gordon
    • Lisa Schonberg
    • Liz Low
    • Marian Quigley
    • Mark Robertson
    • Mary Whelan
    • Meryl Brown Tobin
    • Michael Whelan
    • Mikhaela Barlow
    • Miriam Strickland
    • Natasha Williams-Novak
    • Neil Daly
    • Patsy Hunt
    • Pauline Wilkinson
    • Richard Kemp
    • Sally McNiece
    • Terri Allen
    • Tim Shannon
  • Features
    • Features 2024
    • Features 2023
    • Features 2022
    • Features 2021
    • Features 2020
    • Features 2019
    • Features 2018
    • Features 2017
    • Features 2016
    • Features 2015
    • Features 2014
    • Features 2013
    • Features 2012
  • Arts
  • Local history
  • Environment
  • Nature notes
    • Nature notes
  • A cook's journal
  • Community
    • Diary
    • Courses
    • Groups
    • Stories
  • Contact us

My war on pittosporum

12/8/2021

9 Comments

 
PictureDon’t be fooled by the beautiful foliage and sweetly scented flowers of pittosporum: this plant is a monster.
By Richard Kemp
 
Pittosporum undulatum, or sweet pittosporum, as it is commonly known, is a small dark green tree with a beautiful canopy and a sweetly scented flower.
 
Don’t be fooled. This is not a good tree to have on your property. In fact it is one of the worst. It will have been seeded there possibly from a neighbouring tree. Maybe mine.
 
This species will grow rapidly, spreading its roots, sucking all the moisture out of the ground, at the same time smothering all your other trees by depriving them of sunlight. These are not large trees but they have an enormous root system.

​Seed production on female trees is enormous. Each twig produces eight to 10 bright orange fruits. Each of these fruits has a pod containing about 20 seeds, attractively packaged for easy dispersal by birds, possums and other animals which in turn pass the seeds through their bodies to be deposited with fertiliser.

You can see the results of these deposits especially under the native cherry tree (Exocarpos cupressiformis) where you will often find a ring of about 10 to 15 pittosporum seedlings growing.
 
In other areas individual seedlings quickly spring up, sucking the moisture from the surrounding trees and bushes and eventually killing off all but the toughest of rivals. I see them spread through the bush reserves in The Gurdies.
  
Pittosporum is a declared noxious weed in many areas. Restricting horticultural plantings to male plants is not a solution as most of the male plants also produce occasional fruits. All forms are self-compatible, and plants range from dioecious (distinct male and female plants) to monoecious (a single plant that bears both male and female flowers).
 
I see people cutting down native gum trees and leaving pittosporums.
 
On my property of just less than a hectare, I was guilty of not understanding the gravity of the problem until about five years ago. These noxious trees have almost killed off the native trees on my place by smothering and starving them of sunlight and water. It is taking an enormous effort to rectify, which is why I am producing this article.
 
If you cut them down at the ground, they will sprout again, or the stump will stay alive for years. I drilled some standing trees and poured in Roundup and the side I did not poison survived. I have now had success by drilling in several sides and injecting a mixture of Roundup and Brushoff, but the ultimate solution is to winch them out or dig them out with an excavator. You will understand the gravity of the problem when you see the massive root system these trees have.
Picture
I do not know what effect these roots would have on a septic system, but I think it would be expensive and disastrous.
 
If I cut down all the pittosporums on my property, I am presented with a privacy problem as most of the bush has been killed off so as an interim measure I have cut down or defoliated as many female trees as possible, collecting and burning the seeds.
 
As a custodian of a block of native bush, I still have many trees to remove and many seedlings to pull out.
 
It only takes one active female tree to produce thousands of seed a year to seed our district. I am talking from hard-earned experience.
9 Comments
Pete Muskens
13/8/2021 03:06:29 pm

Good on you Richard
At Cape Paterson we've been trying to get rid of them for years but people who don't know better keep planting or leaving them grow in yards. A pretty successful method for killing them is to cut or saw them close to the ground, scratch around the rest of the stump so that the green sap is visible and then hitting the stump with roundup. Anywhere we see seedlings below two meters we can generally pull them out. In the reserves around Cape Pat we're slowly getting on top of the problem.

Reply
Gill Oscar
20/6/2022 12:20:45 pm

Hi Richard, Our Landcare Group (Springsure Hill) made education and removal of pittos one of our prorities late last year. We run volunteer working bees once a month, and have already seen some neighbours start to take action on their properties. I would love to get more attention focused on this issue as I fear for the impact on biodiversity if we do nothing.

Reply
Mark Quinn
21/6/2022 04:52:01 pm

I live @ Currarong out on the north head of Jervis Bay, we're surrounded coastal heath and pockets rare temperate rainforest and in the 7yrs Ive been here Ive witnessed the spread of pittosporum increase expidentially, espially since 1\10\2020 when RFS Mitigation carried out a backburn (that turned horribly wrong) as part of a bushfire mitigation plan. Effectivly giving what was already a pittosporum problem a clean furtile palate, to reproduce by sucker and seed and thats exactly whats happened, I personly took on the challenge, I started by pruningback all burnt natives, removing the suckers from the trunks of remaining gums, reduced the larger pittosporum to stumps and exposing the roots just your photo, I removed the weeds as they started returning withthe intension of maintaining a good healthy firebreak free of weeds and exotis and my enemy #1 pittosporum. Then Shoalhaven Council issued me with a $3000.00 fine for development without consent, so now Im surroned by weeds metres high and without exageration pittosporum @ a rate of 3 or 4 to the sq. mt. Believe me, Id see the humour in it if it wasnt true

Reply
Nick
13/8/2023 07:29:41 am

Hello Richard. If you know it it, would you provide similar advice for pittosporum revolutum? The website Gardening With Angus says "It naturally occurs from Queensland through to Victoria in rainforests and dry schlerophyll country. It seeds readily and can become invasively weedy in some areas.". Thank you

Reply
Marcia Bookstein
31/5/2024 06:00:49 am

Oh, help. We had a giant pittosporum tenuifolium growing out of our bedroom wall. I was told to have it removed or expect it in bed with us in a few years. So it was chopped down. Lately we've had trees pop up. At first two, now adolescents, but not too close to the house. Now we have dozens of babies, coming out of the brick walkway, edging, everywhere. As I was clearing weeds I felt a very large root and figured I had a giant problem. I'm loath to use Roundup. (Also, I'm superstitious about cutting down trees. Karma?) It scares me and I had a reaction to it long ago--numb hands. Is there something more natural I could use? Vinegar? I live in the city, so a tiller is not practical. Would a shovel work? Thanks!

Reply
Maria Main
16/9/2024 09:11:39 am

We have just discovered that the neighbours pittosporums are the reason our brick garage is coming apart at the seems and he planded more of them on the fence line. I have always hated them but at the nursery where he bought them he was not told of the problems only that they are good hedge plants and that is why he bought them.

Reply
Trey
26/10/2024 06:41:45 pm

Hello
Is this the same as Pittosporum Silver Sheen? Im afraid to plant near the wall if this is invasive. The pic doesnt look like pittosporum silver sheen but could be a family

Reply
Sally Jones
6/3/2025 05:43:11 pm

Please advise is the pittosporum golf ball we have just planted two in small area

Reply
Ryland
1/6/2025 05:10:34 pm

Pulling roots out with an excavator seems like major overkill.
In our rainforest patches near Kangaroo Valley, NSW - pittosporum have been found as a regular feed tree for sugar gliders.
The species occurs naturally here, but it’s population is kept in line be abundant native herbivores as the leaves are highly palatable. Wallabies, cattle, deer perhaps even wombats all eat it by preference. I am in fact concerned by the lack of recruitment of new seedlings/saplings.
As with many “weeds” the level of risk is very context dependent and may in fact be an indicator for a lack of herbivores.

Reply



Leave a Reply.