When Linda Auld took a class at a botanical garden 40 years ago, she could not have foreseen how it would ultimately change her life. The talk by Frances Welden, a butterfly-gardening expert, inspired Auld so greatly that she has been raising butterflies ever since.

There are hundreds of species of butterflies in the U.S., according to the North American Butterfly Association, and many migrate in search of warm weather. Some, like the monarch butterfly, migrate from north to south, while the painted lady, red admiral and others, fly north in the spring and summer.

These colorful, flying insects aren’t attracted to just any garden. Butterflies love bright flowers with red, yellow, orange, pink and purple blossoms, according to the National Wildlife Federation.

Here are Auld’s rules for making your garden butterfly friendly.

1. You need both host plants — butterflies lay their eggs where the caterpillars have food — and nectar plants — those that are food sources for the butterflies.

2. No pesticides! If you see aphids on your milkweed, leave them alone or risk poisoning your caterpillars and butterflies.

3. You want to plant a mix of nectar plants that produce tubular flowers and those with flat flower heads to attract a mix of butterflies with both long and short tongues.