However, a planting of about one hundred daffodils under the same massive Oak tree would look wonderful. Like many things in life, you need to balance the amount of diversity and repetition in your garden. Too much of the same thing is boring. On the other hand, if every plant in your garden were different, no two alike, you wouldn't have a garden but a collection of plants. The effect would be blotchy and broken-up.
Repetition creates a strong visual tie and provides a sense of unity.
For this reason you ideally want to select several varieties of plants to use repeatedly throughout your garden to create a theme and sense of unity. By changing the filler plants you use around your theme plants you can create diversity. Engaging each of the five senses in the garden experience makes the difference between looking at a picture of a garden and being in a garden. A garden is much more than just pretty colored flowers. Plants have texture that makes them not only interesting to look at, but fun to touch.