The cloudless sulphur butterfly. PROVIDED

It was exciting this week to see my first yellow butterfly of the season! Swooping up and down. Darting back and forth. It seems like such a random pattern, yet this butterfly has found the only plant in the neighborhood that she can lay her eggs on. It’s a privet senna (Senna ligustrina); some call it a cassia. The bush is about 5-6 feet tall, with small pointed leaves, and clusters of yellow buds getting ready to open. It blooms off and on most of the year. The seed pods look like string beans and if they are cut off right after blooming, the bush will bloom again sooner!

These yellow butterflies are called sulphurs. Although there are many kinds of sulphurs, there are three likely to be seen here. The largest and most dramatic is the orange barred sulphur, bright yellow with spots of orange on its forewings and a 3-inch wingspan. Slightly smaller is the lemon-yellow cloudless sulphur with a few dots on its wings. The sleep orange sulphur has just a 2-inch wingspan. The adults live from two to four weeks, with the goal of finding a mate and laying eggs on any kind of senna bush.

There are many plants in the senna family in a variety of sizes. Almost identical to the privet senna but shorter is Bahama senna (or cassia). It gets about 3 feet tall and lives three to five years. Both shrubs have an attractive oval shape, keep their leaves all year and are frequently covered in yellow flowers. They are easy to trim, but usually don’t need it. They are native Florida plants, so they grow just fine in our sandy Cape Coral soil. However, I have not seen it sold in big box stores. You can find it in a nursery that sells native plants or at the plant sales at Rotary Park. Often, they are passed along from gardener to gardener.

Members of the Garden Club of Cape Coral are having a huge plant sale on March 9 at Jaycee Park, 9 a.m. to 3 p.m., which they call “March in the Park.” Gardeners in the club will bring hundreds of plants they have grown to sell at this event, including some senna bushes.

Partridge pea is an even smaller plant in this family, which also attracts the yellow butterflies. There are non-native sennas, such as the candlestick plant (Senna alata). These have much larger leaves, dramatic flowers and seem especially attractive to sulphurs. Also, desert cassia, native to the Caribbean, grows to be a small 10-foot tree with tiny leaves yet similar yellow flowers. It thrives in our rainy season as long as it is able to drain freely.

On any of these senna bushes, caterpillars do eat a few leaves, but it is hardly noticeable. I do have milkweed plants for Monarch butterflies. Monarch caterpillars sometimes do eat the entire plant down to bare stems! But not those on the senna bushes. Why not plant a senna bush? Add these lovely yellow flowers to your neighborhood, and entice the yellow butterflies to your yard!

There are many upcoming garden activities this time of year at Rotary Park:

• Florida-Friendly Yard Tour, March 2, 9 a.m. to noon

• Butterfly Garden Design, March 8, 1 to 3 p.m.

• Wild Edibles Walk, March 13, 10 to 11 a.m.

• Design a Florida-Friendly Yard, April 12 and 19.

Sherie Bleiler volunteers at the Cape Coral Library Butterfly Garden and is a member of the Garden Club of Cape Coral. Visit gardenclubofcapecoral.com. Like us on our Facebook page.