Gardening for Life on This Planet
Apr. 8th, 2023 10:54 am![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
kiki_engWhile plants don't go into the ground where I live until the Victoria Day long weekend* it is garden-planning season and people are starting their seeds inside and ordering seeds and plants right now. So, it feels like a good time to post about how you can use plants to support diverse species, how to plan your garden, what kind of things you should be looking for at your local plant sellers and what kind of questions you should be asking them.
*Saturday to Monday before the 25th of May
(The general principles apply globally, but all of the resources that I've linked to are specific to Canada and the United States and/or produced by organisations that operate within those boundaries. There are 22 different links in here, so this got real long real fast and I've accordingly used cut-tags.)
Planting Native
If you want to support local wildlife like birds and pollinators, you want to have native plants. A number of introduced species of plants have escaped their natural predators - the fungi, insects, and other animals that have evolved alongside them to be resistant to the plant's defenses. This means that those introduced species don't support local wildlife - they will not be eaten by caterpillars and other insects which would in turn be eaten by other animals - including birds which rely on insects to rear their young. Some introduced species, because they have escaped their natural predators, out-compete native plants; they are invasive and threaten local biodiversity.
You want to have native plants because some insects are incredibly specialised. By planting native plants you support native bees and caterpillars. Some Lepidoptera*, like the monarch butterfly, have evolved to have very specific larval hosts that they predate and some bees have similarly evolved to pollinate very specific flowers.
*moths and butterflies
When buying plants you can look at specific criteria to help ensure their success: their sun and soil requirements as well as their hardiness zone. When planting native you want to also be looking at your ecoregion to find suitable species. Pollinator Partnership produces eco-regional planting guides for the United States and Canada, which are great for finding your ecozone and provide a good general overview, including plant recommendations. Because they are also designed to serve farmers, they may recommend some plants that are good for honeybees which, like honeybees, are non-native*.
*Clover was the recommendation that jumped out for me - while there are native species of clover, Trifolium spp. in Ontario (which includes red clover and white clover) are introduced.
If you live in the United States, the racist birding association has a native plant database that sorts by zipcode and tells you what birds each plant may attract.
The Ladybird Johnson Centre has recommendations for commercially available native plant species for planned landscapes for every US State and Canadian province and territory, with more regional breakdowns for Florida and Texas. This is a much more complete resource for the United States than for Canada, and if you live in Texas there's a lot more additional content.
Michigan State University offers regional native plant lists for Michigan and also has additional information about native plants for the state. (Local university/college extension services, botanical gardens, and conservation groups often have great resources or great resource people available and are worth checking out.)
The USDA has some good information in their Field Office Technical Guides - filter to your state, select Section 2 - Natural and Cultural Resources Information from the sidebar below, and poke around a little. Illinois has a list of tree and shrub recommendations sorted by soil type, while Michigan has a source guide for native plants and trees.
The Xerces Society has broad regional plant guides for the United States and Canada with some more specific ones for California, Delaware, Portland, and Albuquerque/Santa Fe. You can also access resources through their Pollinator Conservation Resource Centre, which filters by region.
Doug Tallamy's book, Bringing Nature Home: How You Can Sustain Wildlife with Native Plants is a great resource that has regional native plant lists in it, includes information about lepidopteran host plants, and covers a lot of the content in this post. (There's also an associated website.)
If you live in Canada, the Canadian Wildlife Federation has some useful resources, including a native plant encyclopedia that's filterable by province, hardiness zone, blooming season, habitat type, moisture levels, light conditions, flower colour, and so on. They also have supplier lists and webinars.
If you live in Ontario, the provincial government has the Tree Atlas, which offers a very regional breakdown of native trees with links to profiles on each species including growing conditions. They also link to pamphlets by the Ontario Invasive Plant Council on native alternatives to common garden plants for southern and northern Ontario. (There are also updated versions here.)
Plants pass on adaptations to their environment in their seeds; seeds and plants cultivated in your region are better suited to growing in it. Sourcing locally and finding a local producer of native plants or exchanging native seeds with your neighbours is best. Your local garden centre may sell pollinator mixes or pollinator-friendly plantings that aren't native to your region. Ask them for native species.
Going Pesticide Free
Ask plant sellers about insecticidal and fungicidal treatments. Pesticide residues and systemic pesticides harm pollinators and contribute to their decline along with land use modification, climate change, and invasive species. They're part of a death by a thousand cuts and can turn the pollinator habitat that you've planted from being a source of life, to a sink. Neonicotinoids are the big one, and are often used as seed treatments. You may be able to find plants specifically labelled neo-nic free, but you may also find that they've replaced the neonicotinoid with a different class of systemic pesticide, which may also have negative effects on pollinators.
(Amanda Liczner of the Raine Lab at the University of Guelph recently did a talk on her research on the behavioural effects on bumblebee queens, comparing exposure to a systemic pesticide from another class to exposure to a neonicotinoid and to no pesticide exposure. If you want a little glimpse at how some pesticidal impacts are studied it's a good watch.)
You want to buy organic. The Xerces society has a helpful handout on buying bee-safe plants that includes some talking points and questions to ask nurseries about their pest management practices - things like tool sterilization and monitoring for pests.
Planning Your Garden
There's a chunk of Integrated Pest Management practices that you can adopt in your garden planning and will help to reduce your own desire to use pesticides. One of those is planting things so that there's adequate air flow, discouraging fungal growth. Another one is avoiding monocultures. You want to have a diversity of species. A lot of the same species close together facilitates the spread of plant diseases. (Some fungi can use multiple hosts or, like cedar-apple rust, require multiple hosts to complete their lifecycle. There are some families of plants that are more disease prone and easily transmit diseases between species within that family, and some different families that serve as hosts to the same fungus at different points in its lifecycle. Looking up a species' diseases before you plant can save you grief afterwards, or you can embrace how cool your new fungal friend looks. Extension services are great sources of information about plant diseases either way.)
If you do have space and suitable land on your property to foster a threatened habitat like a prairie or a wetland that's incredibly valuable ecologically.
In cases where you're not pursuing grasslands you're going to want to incorporate plantings that will lend structural diversity in addition to species diversity - that is, having a mix of trees and shrubs and shorter plants. This will benefit animals who have different structural requirements for foraging and nesting, increase the number of species that your land serves, and also help with your sound insulation.
Planning your garden around nesting habitats and overwintering sites is a great way to invite those species into your space. The Xerces Society has a really great fact sheet on nesting and overwintering habitat for pollinators and other beneficial insects that outlines useful elements and practices to establish in your garden and who they'll serve. This includes things like leaving some bare soil for ground-nesting bees, incorporating brush piles into your landscape for bumblebees and other insects, leaving stems for stem-nesting bees and leaves for lepidopterans, snags (standing dead trees) or downed logs for leaf-cutter and mason bees as well as some beetles, rock walls or piles for leaf-cutter, digger bees, and bumblebees. Nesting features can serve as points of interest in your garden and can often be constructed in a formal way that will appease a neighbourhood association.
Native plants work well within the aesthetic of the standardised suburban garden - you can easily blend in with your neighbours. A variety of native plants are well-suited to that environment and there are some common elements in landscaping practices that serve that aesthetic and pollinators, like layering plant heights and continually having blossoms throughout the growing season. Solitary native bees (the vast majority of our native bee species) have small foraging ranges (150-600 metres is typical), and having floral resources in close proximity to nesting sites is important: having blooms dotted throughout your garden continuously, serves both goals.
Shallow, gently moving (or frequently replaced so as to deter mosquito production) water with perching places in it in the form of stones, etc. is an important resource for pollinators who need water for drinking, cooling, or nest-building purposes. (The Xerces Society covers this in the handout on nesting also linked above.) Water features are beneficial to many animals and can be designed so that they serve multiple groups of animals or exist separately. The Great Backyard Bird Count has an information sheet on providing water for birds that's really useful, especially since a lot of the commercially available options are poorly designed.
You may choose to naturalise all or part of your property. If you do so it's important to be on the look out for and remove invasive species. Some species persist in the seedbank for years and years, and birds may also deposit new unwanted seeds from neighbouring lands.
Knowing what's growing on your land is important for managing it, whether or not you choose naturalisation. iNaturalist is a great resource for plant identification and one that you can use not just for wild plants - just remember to mark your cultivated species as "cultivated" when you're submitting those observations. Your local garden centre or botanical centre is also a great resource for identifying cultivated plants so that you can determine whether or not they're native, and if introduced, whether or not they're invasive or otherwise a threat to the local landscape.
If all of that sounds like a lot of work, it's because it can be. For many gardening is a passion, an incredibly demanding pursuit, a lifestyle. Others loathe it. The good news about planting native and about planting diversity is that you're creating a system that is a whole lot better at taking care of itself than a vast lawn peppered with exotics. Plants that evolved in the area are adapted to its conditions and are part of functional self-regulating ecosystems. You'll end up doing less watering and when you introduce caterpillars and other herbivorous insects into your life via native plants you are also introducing their predators. You are moving towards a space that will largely take care of itself.
You don't have to make all of your changes in a single year, and you probably shouldn't - you are going to find out things about where you live - what species are there, what does well on your particular patch of land and so on - as you go. Plants can be expensive and gardening is work. You want to be making realistic goals to create gradual improvement. (You don't have to go 100% native, either; Doug Tallamy's suggested goal for landowners to support wildlife is 70% native.)
The Xerces Society has a habitat assessment guide for pollinators in yards, gardens, and parks that helps to identify your current status and meaningful steps that you can take for improvement - it's great for goal-setting. One of its advised actions is allowing your (non-native) basil to flower - there are some really powerful small goals that you can undertake. It includes a community action component with steps like having informational signs so that your neighbours know what you're up to. The guide also includes ways to add value to your fruit and vegetable garden and suggestions that work for container gardening.
Potted plants are important resources for pollinators and can be part of a neighbourhood patchwork that helps pollinators survive and thrive. You can use container gardening to plant native wherever getting plants into the ground isn't possible - in the city or on rental properties, for example. (You may also just like container gardening.) A number of cities also have community gardening opportunities through the city itself or through gardening clubs or horticultural societies.
Find what you can do, wherever you are. Something is better than nothing.
*Saturday to Monday before the 25th of May
(The general principles apply globally, but all of the resources that I've linked to are specific to Canada and the United States and/or produced by organisations that operate within those boundaries. There are 22 different links in here, so this got real long real fast and I've accordingly used cut-tags.)
Planting Native
If you want to support local wildlife like birds and pollinators, you want to have native plants. A number of introduced species of plants have escaped their natural predators - the fungi, insects, and other animals that have evolved alongside them to be resistant to the plant's defenses. This means that those introduced species don't support local wildlife - they will not be eaten by caterpillars and other insects which would in turn be eaten by other animals - including birds which rely on insects to rear their young. Some introduced species, because they have escaped their natural predators, out-compete native plants; they are invasive and threaten local biodiversity.
You want to have native plants because some insects are incredibly specialised. By planting native plants you support native bees and caterpillars. Some Lepidoptera*, like the monarch butterfly, have evolved to have very specific larval hosts that they predate and some bees have similarly evolved to pollinate very specific flowers.
*moths and butterflies
When buying plants you can look at specific criteria to help ensure their success: their sun and soil requirements as well as their hardiness zone. When planting native you want to also be looking at your ecoregion to find suitable species. Pollinator Partnership produces eco-regional planting guides for the United States and Canada, which are great for finding your ecozone and provide a good general overview, including plant recommendations. Because they are also designed to serve farmers, they may recommend some plants that are good for honeybees which, like honeybees, are non-native*.
*Clover was the recommendation that jumped out for me - while there are native species of clover, Trifolium spp. in Ontario (which includes red clover and white clover) are introduced.
If you live in the United States, the racist birding association has a native plant database that sorts by zipcode and tells you what birds each plant may attract.
The Ladybird Johnson Centre has recommendations for commercially available native plant species for planned landscapes for every US State and Canadian province and territory, with more regional breakdowns for Florida and Texas. This is a much more complete resource for the United States than for Canada, and if you live in Texas there's a lot more additional content.
Michigan State University offers regional native plant lists for Michigan and also has additional information about native plants for the state. (Local university/college extension services, botanical gardens, and conservation groups often have great resources or great resource people available and are worth checking out.)
The USDA has some good information in their Field Office Technical Guides - filter to your state, select Section 2 - Natural and Cultural Resources Information from the sidebar below, and poke around a little. Illinois has a list of tree and shrub recommendations sorted by soil type, while Michigan has a source guide for native plants and trees.
The Xerces Society has broad regional plant guides for the United States and Canada with some more specific ones for California, Delaware, Portland, and Albuquerque/Santa Fe. You can also access resources through their Pollinator Conservation Resource Centre, which filters by region.
Doug Tallamy's book, Bringing Nature Home: How You Can Sustain Wildlife with Native Plants is a great resource that has regional native plant lists in it, includes information about lepidopteran host plants, and covers a lot of the content in this post. (There's also an associated website.)
If you live in Canada, the Canadian Wildlife Federation has some useful resources, including a native plant encyclopedia that's filterable by province, hardiness zone, blooming season, habitat type, moisture levels, light conditions, flower colour, and so on. They also have supplier lists and webinars.
If you live in Ontario, the provincial government has the Tree Atlas, which offers a very regional breakdown of native trees with links to profiles on each species including growing conditions. They also link to pamphlets by the Ontario Invasive Plant Council on native alternatives to common garden plants for southern and northern Ontario. (There are also updated versions here.)
Plants pass on adaptations to their environment in their seeds; seeds and plants cultivated in your region are better suited to growing in it. Sourcing locally and finding a local producer of native plants or exchanging native seeds with your neighbours is best. Your local garden centre may sell pollinator mixes or pollinator-friendly plantings that aren't native to your region. Ask them for native species.
Going Pesticide Free
Ask plant sellers about insecticidal and fungicidal treatments. Pesticide residues and systemic pesticides harm pollinators and contribute to their decline along with land use modification, climate change, and invasive species. They're part of a death by a thousand cuts and can turn the pollinator habitat that you've planted from being a source of life, to a sink. Neonicotinoids are the big one, and are often used as seed treatments. You may be able to find plants specifically labelled neo-nic free, but you may also find that they've replaced the neonicotinoid with a different class of systemic pesticide, which may also have negative effects on pollinators.
(Amanda Liczner of the Raine Lab at the University of Guelph recently did a talk on her research on the behavioural effects on bumblebee queens, comparing exposure to a systemic pesticide from another class to exposure to a neonicotinoid and to no pesticide exposure. If you want a little glimpse at how some pesticidal impacts are studied it's a good watch.)
You want to buy organic. The Xerces society has a helpful handout on buying bee-safe plants that includes some talking points and questions to ask nurseries about their pest management practices - things like tool sterilization and monitoring for pests.
Planning Your Garden
There's a chunk of Integrated Pest Management practices that you can adopt in your garden planning and will help to reduce your own desire to use pesticides. One of those is planting things so that there's adequate air flow, discouraging fungal growth. Another one is avoiding monocultures. You want to have a diversity of species. A lot of the same species close together facilitates the spread of plant diseases. (Some fungi can use multiple hosts or, like cedar-apple rust, require multiple hosts to complete their lifecycle. There are some families of plants that are more disease prone and easily transmit diseases between species within that family, and some different families that serve as hosts to the same fungus at different points in its lifecycle. Looking up a species' diseases before you plant can save you grief afterwards, or you can embrace how cool your new fungal friend looks. Extension services are great sources of information about plant diseases either way.)
If you do have space and suitable land on your property to foster a threatened habitat like a prairie or a wetland that's incredibly valuable ecologically.
In cases where you're not pursuing grasslands you're going to want to incorporate plantings that will lend structural diversity in addition to species diversity - that is, having a mix of trees and shrubs and shorter plants. This will benefit animals who have different structural requirements for foraging and nesting, increase the number of species that your land serves, and also help with your sound insulation.
Planning your garden around nesting habitats and overwintering sites is a great way to invite those species into your space. The Xerces Society has a really great fact sheet on nesting and overwintering habitat for pollinators and other beneficial insects that outlines useful elements and practices to establish in your garden and who they'll serve. This includes things like leaving some bare soil for ground-nesting bees, incorporating brush piles into your landscape for bumblebees and other insects, leaving stems for stem-nesting bees and leaves for lepidopterans, snags (standing dead trees) or downed logs for leaf-cutter and mason bees as well as some beetles, rock walls or piles for leaf-cutter, digger bees, and bumblebees. Nesting features can serve as points of interest in your garden and can often be constructed in a formal way that will appease a neighbourhood association.
Native plants work well within the aesthetic of the standardised suburban garden - you can easily blend in with your neighbours. A variety of native plants are well-suited to that environment and there are some common elements in landscaping practices that serve that aesthetic and pollinators, like layering plant heights and continually having blossoms throughout the growing season. Solitary native bees (the vast majority of our native bee species) have small foraging ranges (150-600 metres is typical), and having floral resources in close proximity to nesting sites is important: having blooms dotted throughout your garden continuously, serves both goals.
Shallow, gently moving (or frequently replaced so as to deter mosquito production) water with perching places in it in the form of stones, etc. is an important resource for pollinators who need water for drinking, cooling, or nest-building purposes. (The Xerces Society covers this in the handout on nesting also linked above.) Water features are beneficial to many animals and can be designed so that they serve multiple groups of animals or exist separately. The Great Backyard Bird Count has an information sheet on providing water for birds that's really useful, especially since a lot of the commercially available options are poorly designed.
You may choose to naturalise all or part of your property. If you do so it's important to be on the look out for and remove invasive species. Some species persist in the seedbank for years and years, and birds may also deposit new unwanted seeds from neighbouring lands.
Knowing what's growing on your land is important for managing it, whether or not you choose naturalisation. iNaturalist is a great resource for plant identification and one that you can use not just for wild plants - just remember to mark your cultivated species as "cultivated" when you're submitting those observations. Your local garden centre or botanical centre is also a great resource for identifying cultivated plants so that you can determine whether or not they're native, and if introduced, whether or not they're invasive or otherwise a threat to the local landscape.
If all of that sounds like a lot of work, it's because it can be. For many gardening is a passion, an incredibly demanding pursuit, a lifestyle. Others loathe it. The good news about planting native and about planting diversity is that you're creating a system that is a whole lot better at taking care of itself than a vast lawn peppered with exotics. Plants that evolved in the area are adapted to its conditions and are part of functional self-regulating ecosystems. You'll end up doing less watering and when you introduce caterpillars and other herbivorous insects into your life via native plants you are also introducing their predators. You are moving towards a space that will largely take care of itself.
You don't have to make all of your changes in a single year, and you probably shouldn't - you are going to find out things about where you live - what species are there, what does well on your particular patch of land and so on - as you go. Plants can be expensive and gardening is work. You want to be making realistic goals to create gradual improvement. (You don't have to go 100% native, either; Doug Tallamy's suggested goal for landowners to support wildlife is 70% native.)
The Xerces Society has a habitat assessment guide for pollinators in yards, gardens, and parks that helps to identify your current status and meaningful steps that you can take for improvement - it's great for goal-setting. One of its advised actions is allowing your (non-native) basil to flower - there are some really powerful small goals that you can undertake. It includes a community action component with steps like having informational signs so that your neighbours know what you're up to. The guide also includes ways to add value to your fruit and vegetable garden and suggestions that work for container gardening.
Potted plants are important resources for pollinators and can be part of a neighbourhood patchwork that helps pollinators survive and thrive. You can use container gardening to plant native wherever getting plants into the ground isn't possible - in the city or on rental properties, for example. (You may also just like container gardening.) A number of cities also have community gardening opportunities through the city itself or through gardening clubs or horticultural societies.
Find what you can do, wherever you are. Something is better than nothing.
Thoughts
Date: 2023-04-10 05:44 am (UTC)Re: Thoughts
Date: 2023-04-10 04:20 pm (UTC)By this point, my yard is a sufficiently functional ecosystem that things sprout I didn't even plant. Wild grape vines. Cup plants. Elderberries.
Sounds like the birds have made themselves a home there with those seeds. :)