The May long weekend is the unofficial start of summer. And for those of you with home gardens or access to community space, this is the weekend to dust off your gardening tools and visit the garden centre for the growing season ahead.As we approach the start of gardening season, it’s good time to ask some questions about its origins.Whether you plan to get marigolds, plant a vegetable garden or create a pollinator patch — all gardens have complicated roots.In fact, the practice of gardening is deeply tied to colonialism — from the formation of botany as a science, to the spread of seeds, species and knowledge.Coveted tulipsSome of the most recognizable plants today, such as tulips, are the result of early colonial conquests. Originally found growing wild in the valleys where current China and Tibet meet Afghanistan and Russia, tulips were first cultivated in Istanbul as early as 1055.Later, after they were hybridized and commodified by the Dutch, they became highly coveted status symbols because of their gorgeous, but fleeting, blooms. Exploratory botanical voyages by colonial European powers were integral to the expansion of empire. These trips fueled the big business of collecting global plant samples and also led to the emergence of botany as a scientific discipline.Botanical gardens served as labsBotanical gardens played a key role, serving as the laboratories where plant specimens were organized, ordered and named. “Scientific objectivity” asserted a Eurocentric point of view, disrupting and displacing Indigenous Knowledge and ecological practices.The movement and transfer of plants around the world went hand in hand with the transportation of people to provide a labour force, through slavery and indentured servitude.The plantation system cleared out local ecosystems and replaced traditional farming methods with growing cash crops — like sugar-cane, tea and cotton. These were products meant for European curiosities, markets and profit and not for the local populations.Plant and racial hierarchiesThis colonial system of organizing agriculture laid the groundwork for categorizing people in a similar way, establishing a social hierarchy which dehumanized non-Europeans, helping justify slavery and Indigenous genocide, and eventually leading to racial categories.This history has shaped our current relationships to the land, and our gardens. It also informs beliefs about land ownership and access; who has a right to enjoy the land, versus who is expected to be working on it. Who has the literal and figurative space and freedom to garden?Shifting attitudesBut the soil is shifting. There is a growing shift away from the colonial status symbol of the lawn and manicured gardens, in favour of pollinator-friendly native plants.There is also a growing understanding that centuries-old Indigenous land-based knowledge and practices — like controlled burns — can help manage wildfires, and foster a more resilient landscape.With concerns about our climate crisis growing, one of the possible avenues for creating more sustainable cities may very well lie in our gardens.Could we have an impact simply by thinking a little differently about the seeds we sow and the "weeds" we pull?