"...พยายามปลูกดอกกระดุมทองเหมือนกันครับ กำลังจะปลูกให้เต็มพื้นที่เลยถ้าเป็นไปได้..."

Your wish will come true. Singapore daisy is 'a very invasive/noxious "weed" in Singapore and many parts of the world'. It is useful for sandy dam walls, sandy stream banks, and as ground covers for sandy patches. In good soil, it can be hard to control because of its stolon stems --every bit of its stem can grow-- so, composting them is not advised.

I would suggest trees like 'ทรงบาดาล', 'แค', 'albizia' (มะแค็ก?). They draw nitrogen from the air, drop plenty of leaves and flowers to mulch the soil, they feed birds and bees and many other insects -- not just 'our eyes'. ;-)