Which Garden ‘Weeds’ Do You Actually Need To Remove?

We’re all about biodiverse gardens here at HuffPost UK, and no-mow May is a great time to rewild your backyard.

But sometimes, as is the case with invasive Japanese knotweed (which can cause structural damage to your home if not treated ASAP), certain plants are better off out of your yard.

So, we thought we’d ask the Royal Horticultural Society (RHS)’s chief horticulturalist, Guy Barter, about which ones you should banish on sight (and others you should keep a careful eye on, as well as the ones you should bear with).

“Some alliums, such as:

• three-cornered garlic, and
• crow garlic

are extraordinarily tricky to winkle out as they leave little bulbils behind when uprooted,” the gardening expert told us.

“Never let them gain a lodgement in the first place, ideally.”

Three-cornered garlic (AKA three-cornered leek) is an invasive species that can smother native wildflowers. It’s an offence to cause it to grow in the wild, and it can be removed by hand-weeding the bulbs.

Crow garlic, meanwhile, spreads very easily and can take over your garden if you’re not careful. Fork out seedlings or smother plants with e.g. cardboard and bark.

“In general, gardeners would be unwise to leave invasive weeds such as:

• bindweed,
• ground elder, and
• couch grass

to their own devices,” Barter told us.

“Not only are they very invasive, but [they] are [also] hard to dislodge.”

Bindweed, while sometimes beneficial for wildlife, can be very hard to remove from your garden due to its enormous and rapidly spreading roots. It can be controlled by placing physical barriers at least 45cm into the ground, deadheading flowers, smothering young plants, mowing often, and forking out seedlings.

Ground elder can lead to a “carpet of leaves”. Fork out plants, smother them, place a barrier 45cm or more deep around them, mow more, and pull off new growth.

And couch grass, which can spread like wildfire, can be forked out or smothered.

“Many garden plants are very ‘willing’ and although valuable in places where other plants won’t grow, can run amok in fertile, sunny, moist soil,” Barter said.

• Solidago,
• certain bamboos,
• montbretia,
• mind-your-own-business [Soleirolia soleirolii],
• borage,
• horseradish, and
• mint

“Come to mind,” he added.

That’s not to say they need to be removed, though.

“Constant vigilance and an occasional going round with a spade ensure these plants stay in [their] lane. Repeat transgressors must go, however.”

Slightly annoying plants can still be worth it, considering how useful they are to your garden’s ecosystem.

“Some unwanted plants like:

• nettles,
• green alkanet,
• thistles,
• sow thistles, and
• hedge mustard,

although apt to spread, can be given a little slack in view of their value to insects.”