Gardening for Conservation?

I recently found out about the karner blue butterfly, which has been extirpated from Ontario due to the near-extirpation of its host plant, sundial lupine. I was thinking, could gardeners bring this butterfly back to Ontario? If everybody in suitable habitat planted some sundial lupine in their garden, would we be able to bring the karner blue back into its former range?

So then, I thought about what other similar cases there are out there. What other at risk insects can be brought back through planting specific plants? Are there any at risk plants that would benefit from being planted in gardens? I tried looking into this topic, and was able to find practically no information on gardening to protect endangered plants and insects. I would’ve thought that conservation authorities would want to enlist the help of willing gardeners to help out in conservation efforts, but that doesn’t seem to be the case. Does anyone know why there doesn’t seem to be any info on the topic, or know where that info is hiding?


More resources here:


I wasn’t so much looking for examples on the karner blue, but on gardening to protect all endangered species. What plants can be protected by being planted in a garden? What insects would benefit from people hosting their host plant more? etc. The karner blue was just an example.


Just offering some local-to-me context/ examples about a partial success and the intensive management of lands often required to bring back species. I wasn’t responding specifically to your question just adding relevant content to the discussion. If you’d like me to remove my post I can.


It’s totally ok, no need to remove it. I just misinterpreted your reason for adding info on the karner blue, and thought that I’d clarify what my ideal topic for this thread was.


If there’s a native plant society near you, they might be able to suggest species to plant or could refer you to people who might know what at-risk animals could use your support. In the US, we have the Cooperative Extension program funded by the government and run by agricultural colleges and universities that covers all manner of practical info about gardens, insects, crops, and such; plus, they have contacts at universities they can ask for information. I’m not sure if Canada has anything like that, but I suspect you would.


In my area, there’s been encouragement for years to plant milkweed for monarchs. But, it seems, any old milkweed will not do… it seems, there are specific milkweeds to specific locals that are actually helpful to monarchs, which is hardly ever mentioned.


I’ll look into native plant societies, thanks! Sounds like a great idea.

1 Like

To me, milkweed and monarchs is a weird example of an endangered insect with a specific host plant. Where I live, milkweed is extremely common, and monarchs are pretty easy to find. I’m not sure if monarchs still need help from milkweed planting in my area or not. Of course it couldn’t hurt, but they don’t seem to be like the karner blue where their host plant is almost completely gone.


A few decades ago, the Santa Cruz/Monterey Bay coast had select groves with hundreds of thousands of Monarch in the winter. The same groves now are lucky to see 1000-2000 individuals. People have been encouraged to plant milkweed to offset the destruction of habitat, etc, but it doesn’t seem to be working well. Last year, a native plant person told me most people were planting the wrong kind of milkweed.:confounded:


The big idea is to promote native plants, and to reduce the impact of invasives. It sounds simple, but it will do a lot for biodiversity, including assisting species-at-risk. There is a lot of info on these topics specific to Ontario, but I can’t think of anything comprehensive, so here are a few links to get you started:

  • Recent TRCA inventory of High Park, this is applicable if you are near a black oak savannah remnant, or you want information on that plant community. This is a detailed report that provides information on the status of many plants in the Toronto area, if that is relevant for you

  • In the Zone - a joint project of the WWF and Carolinian Canada designed to get individuals to plant more natives to support biodiversity. As a side note, the In the Zone team would likely benefit from incorporating plants from the TRCA list given the west-Toronto focus of the program.

  • Invading species awareness program (ON) - information on the worst invasives in the province

  • List of sources for native plants in Southern Ontario - as finding properly sourced plants requires a bit of effort

  • One example of planned local reintroduction is the Mottled Duskywing, it is not (yet) extirpated in the province but it is only found in a few locations. This butterfly has specific host plants (New Jersey tea and prairie redroot), both of which have suffered significant habitat loss. You do need to have a lot of plants to support a new population though.

  • Interestingly, the lupine is doing well in curated areas like the Pinery, High Park and areas in Norfolk. The Lupine Leafroller moth (not nearly as attractive as the Karner…) was also thought to be extirpated until someone checked a rejuvenated lupine patch, now it is being found by the dozen on a good day in high quality areas.

And yes, monarchs aren’t endangered due to a lack of food plant in Ontario. As you note, milkweed species are common and locally prolific.

Based on anecdotal conversations with reps from conservation groups, they would love the type of assistance that you talk about, but outreach is a challenge for budget-constrained organizations. Most of them would like help pulling garlic mustard etc, which could be almost as valuable if it is helping to protect an ESA or ANSI.


Endangered plants in garden doesn’t seem too good, you need a plant from local population and it’s not a good idea to dig it out from somewhere while garden cultivars, etc. can be genetically totally different from local plants.


Douglas Tallamy has done a lot of research on the connection between native plants and caterpillars (using caterpillars as a stand-in for insect herbivores in general), and linking that to bird populations.

He is currently focusing on people planting nativesto support wildlife populations.
Nature’s Best Hope shows how homeowners everywhere can turn their yards into conservation corridors that provide wildlife habitats.”

He has published 3 books, and has a website here:


It’s funny you mention it - Last year I also found out about the Karner Blue butterfly, which has similarly been extirpated from Pennsylvania (my home state). I thought it would be wonderful to expand habitat for it and try to bring it back here. But after some research it seemed like a monumental task - even at their peak, they had a minimal range here in PA, which isn’t anywhere close to where I am. There is one small existing oak savannah, and it would take a huge effort to restore the butterfly there and the lupine on which it feeds, meanwhile also making sure that the lupine doesn’t hybridize and become useless to the butterfly. The Karner blue also has a remarkably short range, only travelling a few hundred feet if I recall correctly - so it’s unlikely that they will re-establish themselves in a place distant from an existing population. It would take human intervention. The good news is that places that have restored and protected the Karner Blue have also (as is frequently the case) created a good habitat for other native species and supported biodiversity there. I thought maybe it would be a better use of funds to support them and make sure our existing Karner Blue populations stay safe.
Yeah, there should be better ways to identify species in trouble that are local to us, so we can try to fill that niche where we are. You hear a lot about the monarch but little else.
The Pollinator Partnership has made me aware of the decline of the Rusty Patch Bumble Bee in my area, and they are working to try to create habitat for it and the monarch as a focus. I heard about a small specialist bee that reappeared after a century of being AWOL, and it makes me want to plant Heuchera that it lives on. It would be great if there was a map that could inform about endangered species that gardeners can focus on helping. States keep lists, but navigating is a mess.


Here in California, I would say we have a lot of groups working toward these exact goals. Try the native plant societies, small restoration/conservation groups, etc. For example, here are just two local non-profits that work tirelessly to remove invasives, restore native and endemic species, and educate about people using those plants in your landscape.
Friends of Ballona Wetlands:
Theodore Payne Foundation:

Frankly, even our water agency, DWP, has pages of material on it’s site about water-wise gardening and California friendly plants.

I’ve been trying to incorporate more natives into my garden and it is paying off in terms of more birds and insects visiting as well as helping lizards thrive. I would add that it’s not just about what plants you plant, but I allow the leaf litter to remain under the trees and bushes. Not only does it save in trash removal efforts, but it helps nurture the soil and returns nutrients while also providing new habitat for myriad insects. This in turn is a wonderful food source for birds who come and scratch under the leaves for a tasty treat.


This is a topic close to my heart and although I’m literally half a world away from you, living here in South Africa I just want to encourage you that butterfly gardening really, really does work!
We have a small garden quite close to the centre of Pretoria and over the years we have been able to attract more and more things that one would normally expect only in the countryside. I think the principles are fairly simple and universal. Plant local plants (preferably not fancy hybrids) and don’t use any poison. I’ve more than once had people admire the butterflies in our garden and then tell me how to get rid of the worms in the trees!
Remember its not just the very rare species that are taking strain. Its also sad when a species that should be common is now hard to find. Here in South Africa quite a lot of the butterflies that rely on thorn trees or mistletoes are now scarce in town because “good gardeners” have eradicated the host plants. It really is possible to garden in a way that is really beautiful, yet gives good habitat for all sorts of creatures.


About Karner Blues specifically, there have been more than one successful restoration effort here in Wisconsin done by thoughtful people on their own property. I don’t believe they were reintroductions, just expansion and preservation of existing populations. The tools that ensure the restorations remain and last include conservation easements. They allow the work people do to preserve their habitats to outlive them.

For the homeowner with less land and a desire to conserve any species, there are many opportunities once you get looking around. The key in these situations is to work on a local culture of conservation that extends beyond your own yard. I’m acutely aware of that necessity from my recent experience. I worked for three decades to create nice gardens around our home and eventually certified our property as a wildlife habitat and as a pollinator habitat through conservation organizations. This past spring we sold the house and moved and last weekend I spent some time returning to retrieve some of the more rare plants with the kind permission of the owner. Why? They are turning the gardens back into lawn. I knew it was a possibility and I’m not too broken up about it. Because there is a shifting mosaic of ownership in such neighborhoods over the years and decades they’re poorly suited to long term conservation unless that mosaic includes enough individuals with a shared interest. Bottom line: talk to your neighbors and your broader community and get them on the conservation bandwagon.


The nurseries sell the one with pretty flowers, which appeals to the customers. Learning which one to plant in my garden, is the next step.

1 Like

You are correct that this is a concern. Happily though, in the area that MWS lives, there are several nurseries that ethically source seeds. Local conservation groups often purchase from the same places.

There is a very good book by Heather Holm, Pollinators of Native Plants. I believe that she lives in Minnesota, but the book is helpful for people around the Great Lakes. Heather is also on iNat:


That is true in many places. In the Dominican Republic there are monarchs, as well as other species of the same genus. But they are scarce, as are the milkweeds, because farmers consider milkweed toxic to their cattle.

Incidentally, one of the important milkweeds for monarchs in the Dominican Republic, Asclepias curassavica, is also a problem for monarchs when people plant it in, say, California – because it is tropical, it does not go dormant when North American milkweeds do, which encourages the monarchs to stay around instead of migrating when they are supposed to.