I have created a border of 30cm deep around a man hole in the middle of garden. I need advice on the sequence planting bulbs and

Question

dahlias so i can get bloom through out the spring and summer I have created soil condition which will have adequate drainage hopefully.
As i do not wish to takeout the bulbs and tubers at the end of season, and wish to avoid removing and planting every year
Thank you
All advise will be highly appreciated
Thank you

Answer 1

Dahlias are hardy to -12 degrees Celsius (10 F), so they should work in your area. I would plant the dahlias in the outer circle and the bulbs on the inside. That way when the dahlia foliage grows, it will hide the bulb foliage that needs to remain till it withers. You don't say which spring bulbs you'd like to plant, but here are some options. However, planted, they will bypass whichever ones might be in the way. Or you can plant them lasagna style, layering them above each other separated by a layer of soil. The article on succession planting will help. Also, the spring bulbs can be planted in fall and the dahlia tubers in spring.

https://www.gardeningknowhow.com/ornamental/bulbs/bgen/succession-planting-with-bulbs.htm
https://www.gardeningknowhow.com/ornamental/bulbs/bgen/spring-flowering-bulbs.htm