hi! i have not found borage to be invasive. it does reseed but the volunteers are easily identified and pulled out. my problem with borage is the hairs all over it make my skin itch so i need to wear gloves. it is a large (~3ft), hairy, sprawling plant that will need a bit of room. i've never tried, but it can probably be trimmed back to keep it more manageable. grows very easily here. the flowers are pretty, even if the plant is not, and bees love the blooms. i've never tried it as a pest repellent. hope this helps--happy spring! --bonnie