Erigeron philadelphicus is a herbaceous plant with alternate, simple leaves, on hairy stems. The flower heads are borne in spring in arrays of as many as 35 heads. The stem is hairy with rough hairs. The middle to lower leaves are heart shaped, and the plant is about 0.5–2.5 ft (15–76 cm) tall.
Once established Mexican fleabane is known for being drought-tolerant. While it's establishing, it does best when watered regularly. This is especially important during hot summers when care should be taken to ensure the soil isn't left dry for prolonged periods.
Although Mexican fleabane prefers a sunny position, it can still grow in partial shade—it just might not flower as abundantly.
Monthly applications of liquid fertilizer during the spring and summer growing season will help to boost Mexican fleabane flowering potential.
The best results for Mexican fleabane are seen when it's planted in fertile and well-drained soil. However, it's pretty robust, and this is why it can still do well growing in rock gardens and paving cracks.
Deadheading spent flowers can promote a prolonged blooming period. By cutting it back heavily in the fall, this can help to keep the new growth compact and not overly leggy.
Unsurprisingly, Mexican fleabane does well in warmer climates. It isn't a fan of excessively cold or damp winters, but it can still survive in USDA zone five. In these temperatures, Mexican fleabane benefits from dry mulching during the winter, and a sunny summer season and well-drained conditions are vital.
