You plant something pretty, it grows beautifully, and a year or two later your neighbour is knocking on the door to politely ask why it’s now coming up in their lawn. Plants don’t read property deeds. Some of the most popular garden choices spread through underground stems, runners or climbing growth, and they cheerfully cross a fence or a boundary wall without so much as a pause. A few can even become a serious headache between neighbours. Here are seven plants known for crossing the line, along with what you can do to keep them where they belong.
If you love bamboo, choose a clumping variety instead, or install a deep barrier, around 60 to 75 centimetres, around the planting area, leaving a little above ground so you can spot any escapees. Its roots can travel far underground, and a barrier of at least 45 centimetres is recommended to stop them. Bamboo is a favourite for quick privacy screens, but the running types spread through underground stems called rhizomes, which can travel well beyond the spot where they were planted. They can pop up in a neighbour’s lawn and even push through paving. Pudina is a kitchen essential, and it’s also a famous garden bully. Mint spreads through creeping underground stems that break easily and regrow from small fragments, so pulling out a bit often makes it spread even more. It quickly crowds out smaller plants. The easiest solution is also the simplest: grow it in a pot rather than directly in the ground, and keep the pot from touching the soil, so the roots can’t slip out through the drainage holes. Bindweed has delicate white or pink trumpet flowers, but it is a relentless climber that twines around everything in its way and pushes through gaps in fences. If a neighbour’s bindweed is creeping into your garden, remove the stems as they appear, and don’t let them set seed.
