This is a huge subject, and unfortunately there is no one size fits all planting solution!

Your best bet is to answer a few questions before you plant anything: What types of bees do I want to provide food for? What can my environment support without amendments? In addition to food (nutrition) do the bees have a good place to live? Will the bees have food throughout their season? What exists for bee food now?

Certain plants produce nectar and pollen as incentives for bees and other insects to help them with plant reproduction, also known as pollination.

What types of bees do I want to provide food for?

Some bees (like Honey bees) are generalists, in that they get nutrition from a variety of plants.

Some bees (like Squash bees) service a plant category only, in this case “squash”, or more specifically summer and winter squash, gourds and pumpkins.  They don’t, for example, visit any of the mints.  If you want to provide food for them, you’ll need to plant squash of some sort.

What can my environment support without amendments?

Some plant requirements, like maximum and minimum temperature are fairly easy to understand.  Growing a plant native to a tropical rain forest in the arctic is likely an exercise in futility!

The USDA developed Plant Hardiness Zones in part so an easy determination can be made of what plants can survive where.  The University of Maine Cooperative Extension says Maine ranges from Zone 3 to Zone 6. (https://extension.umaine.edu/gardening/manual/usda-plant-hardiness-zone-map/)

Why “without amendments?”

Think long term here.  Eventually you will be gone and the plants need to survive without manipulations to their environment.  We’re not talking providing water to new plants, but providing lime and amendments intended to alter the environment so that plants will grow better.  Think too, what sorts of plants traditionally grow where you are (natives.)

There are other things to keep in mind like regional soil types and natural water levels.  Fortunately, your local uMaine Cooperative Extension County office knows your region and has the resources for figuring all this out!

Is it native?

An argument in favor of planting only native plants is that native pollinators have had the chance to evolve with them. Honey bees as generalists make use of many native plants. While not in Maine, the website Go Botany: Native Plant Trust (headquartered in Framingham, Massachusetts) lets you see the native status by county! Unfortunately, many plants shown in native plant catalogs are not native to Maine.