By Winbob
United Kingdom 
I am taking up a dry old buddleia as I am having my drive done. I thinks it's really too old to cut back and start again. I want to replace it with a new buddleia. Would the roots be detrimental to my new drive? can anyone suggest shrubs which flower, with small root systems, ( as you can tell I have no clue about gardening)!
6 May, 2016
Answers
Buddlejas have tiny root systems compared to their size - that's how they manage to grow in brick-walls. Correct pruning all limits the size of the root ball.
Choose a medium size cultivar rather than a mini-one (mostly useless) or a random wild-type.
My recommendations - Gulliver, Summerhouse Blue, Sugar Plum, Purple Emperor (5-6ft). Buzz Ivory, Red or Sky Blue (4-5ft) if it is not too exposed.
6 May, 2016
Well generally, the smaller the plant, the smaller the root system, but need some more info please - how close to your new drive do you want to plant? Sun, shade, windy, sheltered? What part of the UK are you in (up north and you'll need hardier plants)? And what material is the drive being constructed out of?
6 May, 2016