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Effective Ways To Deal With Common Weeds As The Weather Warms Up

ABC Everyday / By Zoe Kean

Longer, warmer days are causing plants all over Australia to spring into new growth. But with this welcome growth comes every gardener's nemesis — weeds.

Amanda Sigler, 38, grew their "first ever garden" last summer and has been gaining new skills to keep weeds at bay.

Here are their tips, along with advice from a horticulturalist. 

Prevention is key and cardboard can help

The strongest advice Amanda has for new gardeners is to stop the problem before it starts through weed-wise planning.

"Lay a good foundation," they say.

When Amanda moved into a rental in Moonah, a Hobart suburb, they were faced with an expanse of lawn. After getting the go-ahead from their landlord, they decided to replace the lawn with veggie beds.

They dug up their lawn then lay flattened cardboard over the dirt to stop the grass regrowing. They topped it all off with fresh, premium, weed-free soil.

This strategy gave their new veggies the best chance of growing without competition.

Louise Sales, horticulturalist at the Botanical Institute, a garden run by the Museum of Old and New Art's (MONA) 24 Carrot Garden Program, endorses this method. 

"If you've got lots of weeds [laying cardboard down] is a really good way of suppressing them," she says.

Occasional weeds still blow into Amanda's veggie patch, but the intruders are few and the quality soil makes them easy to take out.

"I don't go out intentionally to weed, I go out to be with my plants, I talk to them and tell them they are doing a great job and that I'm proud of them," they say.

"If I see that weeds are impeding on the veggies growth then I will pull them [the weeds] out."

Keeping the problem small

Amanda is wise to keep a watchful eye over the patch.

Louise warns that small weed problems can turn into "much bigger problems" if left alone.

Weeds that pop up seasonally are called annuals and include species such as cape weed and dandelion.

"With annual weeds the key is to get rid of them before they go to seed," Louise says.

"If you are trying to work out which weeds to target first, it's the ones with the flowers on them.

"For ones with deep tap roots like cape weed and dandelions you really need to dig out the root or they will just regenerate."

Luckily, these can be the most fun to pull out.

"When you get a whole dandelion you can pull all the leaves together, twist and pull it out all in one go — it is very satisfying," Amanda says.

Know thine enemy

Some weeds are particularly pernicious.

Beyond the veggie beds, Amanda's garden is plagued by mallow.

"It's really intense and you have to kill it at the root, but the root system is prolific," they say.

Louise identifies a grass called rope twitch or couch as "the bane of most gardeners' existence".

"It looks like a grass from the top, but you can distinguish it from other grasses once you dig it up [because] it has got this long spaghetti-like root," she says.

Rope twitch uses its long roots to spread underground, therefore the whole plant, roots and all, needs to be dug out or it will spread, just like mallow.

When annual weeds do not have seeds, Louise says they can go in the compost.

However, rope twitch is strong enough to survive a spell in most home compost systems so she recommends disposing of it in a green waste bin.

"My second nemesis is bramble," she says.

Brambles are invasive wild berries. They are thorny, fast growing and often delivered to your garden via bird droppings.

"It's really hard to pull up, you need to dig it up and wear two pairs of gloves."

Befriend your weeds

Occasionally uninvited plants bring unexpected joy.

"Some things come up, and I don't know what they are, so I think: that is kind of cute, let's see what happens," Amanda says.

Amanda was delighted when one of these mystery plants turned out to be a nettle.

"I don't know how it got here or where it came from," they say.

"I've been trying to let it grow, I'll harvest and dry it for tea."

Louise agrees that uninvited plants, like nettles, can be a valuable addition to your garden.

"Dandelions and nettles are all highly sought-after by chefs, so what you think is a weed might actually be quite tasty and good for you," she says.

Here's a guide to what is safe to eat.

"Some things are weeds, but I think they are pretty, so I leave them there," Amanda says.

"If it's not colonising my garden bed it doesn't bother me."

Zoe Kean is a science writer and communicator based in lutruwita/Tasmania. She loves living things and has a small but blooming garden.