The addition of annual plants to a primarily native yard offers huge benefits to pollinators, increases biodiversity and some can even feed larval caterpillars. Many annuals are native perennials from the west coast making them annuals on the east coast. A few years ago, I chose to add plenty of open pollinated heirloom annuals to my landscape in order extend my growing season for the wildlife here. It worked beautifully! My biodiversity exploded! I have plants in bloom from late March to November and I’m in zone 6!
In a perfect world, we should be re-wilding with 100% native plants and leaving it untouched – just like nature. While I support this, I’m aware that many people haven’t transitioned to that idea yet. There are also limitations like Homeowners Associations, and city grass mowing restrictions that hinder re-wilding efforts for homeowners that would like to do that --yet can't. For example, one can be fined for having grass taller than 6 inches in my city; effectively shutting down growing meadow like lawns that are needed for pollinators.
I really don’t care how one creates a biodiverse landscape- be it pure re-wilding if you can, a planned small space of potted plants-- or whatever --- just CREATE ONE! At a minimum, there should be 70% percent native plants, but those extra annuals are important, too!
Disclaimer!***** Tropical Milkweed and Hairy Balls Milkweed, to my dismay, are big sellers around here for Monarch butterflies. Please DON'T BUY THESE PLANTS. These are not native perennials to our zone and are annual plants. Most are not grown locally, and they bring in the deadly Monarch disease OE which runs rampant in the warmers states from which these plants come. These two milkweeds also extend the growing season of milkweed, keeping monarchs here laying eggs upon them when they should be leaving to over winter in Mexico. Should you insist on having these plants-- please be responsible and grow your own from seed, and remove them when our perennials milkweeds die back. Annual plants used for extending growing seasons should support native wildlife ---anything that would hold a migratory creature here pasts its migration time-- should not be left growing.*******
Benefits of Annual Plants
1. Some are very high nectar which supports adult insects.
2. Long bloom times extend feeding pollinators until late in the year. My Cosmos produced well into October. ***** see disclaimer above*********
3. They provide variety food sources
4. Self-Sowing – it does the work of expanding your bloom season for you
5. Can feed larval caterpillars—think of annual herbs like dill, fennel, parsley grown in pots can have their own butterfly area
6. They provide nest material
Choose heirloom annuals that are open-pollinated, self sowers, but have no chance of becoming invasive perennials. Seek out native perennials from the opposite coasts to keep as many native plants as possible, whether annual or perennials! Don’t dead-head every single flower if you want self-sowing to happen to extend your growing season. Annuals come in many different shapes—be sure to include flat disk flowers like Cornflowers to feed the short-tongued, tiny bees. The carder bees also use the silver fuzzy hairs of the leaves and stem for nest material. Include deep flowers for long -tongued bees. Add as many flower shapes as possible. and visiting insects will not only increase in numbers, but species type will as well.
Get crazy with your planting ideas! Aside from no chemicals, and more natives than annuals There are NO rules to designing your pollinator landscapes! Mix it up, and watch the biodiversity explode. Have fun.