Bogturtle's GardenCut it down and soak the stubs with herbicide. Let it go for a month, and then plant close to it. I have drilled holes into some stubs, so the herbicide sits and soaks in. Your replacement may mask or hide the ugly stuff. As to substitutes, I have the very low growing Forsythia 'Goldtide', which, after 5 years, here, is about a foot tall, very matted and dense and over a yard wide. I am enthusiatic about dwarfer growing Viburnums, like V. farrari 'nana' and V. carlessi 'Compactum'. Oakleaf Hydrangea dwarfs, Nandina dwarfs, and any number of others, like Fothergilla and Berberis and Lilac. Granted I live in zone 7a, so my success might not be yours.

http://bogturtlesgarden.blogspot.com/

You can absolutely dig them out- here's one my husband did in preparation to move our fence. He removed six of these bad boys.

Not to say it didn't require some effort, but you just have to make up your mind to do it and get busy digging!

Why don't you train your forsythia to grow as a tree. I am working on this with one of mine and it is working well so far.

if he has a pickup.. does he have a sawzall .. lol ...

first buy a tree pruning blade for it ...

then sharpen a shovel ... it matters ..

start by cutting the plant down to about 3 feet.. leaving a couple large trunks to heave back and forth ....

then start digging about 3 to 4 feet out from the plant ... using the sawzall to cut huge roots .... and using the trunks.. to find out where the next one is ... once its starts moving ...

we all like to minimize work by using a truck in the garden .. lol ... but 99.9999% of the time .. unless you exercise your checkbook ... its just a lot of hard backbreaking work ...

pay attention the the utilities if its near the house ...

ken

https://www.youtube.com/watch?v=tSyffcDMSD8

Any form of digging is easier if the soil is damp. Often the solution is to water well, then wait a day or two for the soil to dry from soggy to moist. It can be the difference between digging concrete and digging dirt.