Invasive Species, Public Money, and Staying Grounded –
A review by Dorothy and Patrick Smyth (retired accountants) of the Auditor General’s comments from an accounting perspective for discussion purposes.
Invasive species are a real ecological concern, and this is not in dispute. Within Master Gardener circles, there is broad agreement that invasive plants pose challenges for ecosystems, natural areas, and long-term management. The more difficult question is how governments understand the problem, allocate public resources, and communicate clearly about what can realistically be achieved.
Reading the Ontario Auditor General’s Value-for-Money Audit: Provincial Management of Invasive Species from an accounting and governance perspective highlights a central issue: the report is not primarily about individual plants. It is about systems — how costs are tracked, how priorities are set, and whether public spending can be shown to deliver value for money.
The Auditor General identifies several significant financial and governance gaps. Ontario does not have complete or consolidated cost data for invasive species management. Spending is fragmented across ministries, municipalities, conservation authorities, and capital programs, with limited cost allocation by species, activity, or outcome. As a result, the Province cannot reliably assess which invasive species drive material public costs or which interventions are most effective.
Much discussion has centred on the Auditor General’s inclusion of a list of invasive plant species that have not been fully assessed or regulated. It is important to interpret this list carefully. The list functions as evidence of a management gap — demonstrating that Ontario lacks a comprehensive, timely process for identifying and prioritizing invasive species risk. It is not presented as a recommendation that these plants should be banned, regulated, or removed.
Invasive species vary widely in their impacts. Some create serious canopy, infrastructure, or public-safety liabilities. Others are persistent but localized, or problematic in some settings and relatively benign in others. Treating all invasive plants as equivalent oversimplifies a complex reality and risks misdirecting attention and resources.
From the only cost figures available (2019), Ontario spends $50–$60 million annually on invasive species. Of this, only about $21 million is attributed to broad categories. Of that, about 86% of all reported expenditures are for canopy/urban forestry (EAB, pests), aquatic/infrastructure liabilities (mussels, sea lamprey, carp), and episodic large-scale public programs (e.g., gypsy moth). Of the balance, $2.6 million was spent on plants: Phragmites ($1.3 million), wild parsnip ($480,000), European buckthorn ($429,000), DSV ($108,000), giant hogweed ($99,000), autumn olive ($93,000), Japanese knotweed ($78,000), garlic mustard ($36,000), glossy buckthorn ($13,000), Manitoba maple ($5,000), and Scots pine ($5,000).
The dominant costs are clearly not ornamental horticulture, and plants are of residual consideration.
It is important to be realistic about what is achievable. The removal of all invasive plants from urban and peri-urban landscapes is not feasible. Where invasive species are widespread in natural areas, unmanaged lands, or transportation corridors, reinvasion into home gardens is likely regardless of individual effort.
When government formally assesses a species and regulates its sale or distribution, expectations are clear and enforceable. Where no such regulation exists, implying that individual gardeners can resolve a landscape-scale problem through voluntary action alone risks creating false expectations and unnecessary tension.
The Auditor General’s report is best read as a call for better information, better cost accounting, and clearer prioritization — not as a mandate for expanding plant lists or moralizing plant choice. Staying grounded in what the evidence can and cannot support helps maintain credibility, public trust, and constructive engagement across the gardening community.
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