Make weeds work for you

Marilyn Phillips says these foxgloves will help an apple tree become resistant to disease. Be warned they are highly toxic, especially to children.
Marilyn Phillips says these foxgloves will help an apple tree become resistant to disease. Be warned they are highly toxic, especially to children.

If you type "good weeds" into Google, a great deal of the 63.4 million hits are about illegal plants.

Let's go straight from the start - this story is not about marijuana. But it is about those unwanted stragglers in your garden and how many can be put to good use. Some can't, but they can be dealt with naturally.

The good ones can draw water and nutrients from the soil, help control insects, protect topsoil and prevent erosion, promote plant health and be used as food for the garden and people.

At Hollard Gardens in Kaponga, Marilyn Phillips has sage advice about wandering willy, foxglove, oxalis, lamiums, plantains, chickweed, nettles, arum lilies and even gorse.

She has just led a workshop on weeds, so is schooled up on the good and the bad.

"It's just about plants growing in the wrong place - that's all a weed is really," the gardener says.

First on her list is common foxglove (Digitalis purpurea), which is planted by an apple tree or fruit guild in the food forest. "Foxglove helps plants become resistant to disease," she says. "It's beneficial to any plant it's next to." But this plant comes with a poison warning. "It's something I wouldn't have around small children. Just one bite of the leaf . . ."

To prevent an invasion of foxgloves in your garden, you need to take action. "You must pick the spent flower head before it seeds - one year of seeding, seven years of weeding." If it's too late already, cut the seed heads off and burn them. Other invasive plants, such as wandering willy, oxalis, thistles and couch grass, can't be put in the compost untreated because they can grow again and be spread with the compost.

Marilyn has the answer: "Anything you can't compost, you can make into liquid fertiliser," she says. Get large buckets or bins with lids, stuff full with weeds and then pour in water until the plant is covered. Put on the lid to keep in the smell (your neighbours will appreciate this) and leave to rot away. "You can stick them under a hedge or in the back of the section out of sight," she says. "Once they have rotted down, you strain the juice off and use that on the vegetable garden." The rule with all liquid fertiliser is to water it down to the colour of weak tea before using it.

The leftover pulp in the strainer can then go into the compost.

If the oxalis corms are still quite hard, Marilyn recommends straining off the liquid for feeding plants, popping the bulbs back into the bucket and refilling with water.

Sometimes, a garden of weeds is better than nothing, especially on a roadside verge.

"A lot of people are tempted to go and spray it, but it's a beneficial little ecosystem with insects that are helpful," she says. "Then you spray it and you've just got a desert there or you get weeds that are more resistant to sprays and chemicals. The more diversity in the weeds, the more they have to compete with each other." On top of that, many of the plants can be extremely useful and pretty.

Nasturtiums fall into that category. "You can make the little seed heads into capers," Marilyn says.

Cleavers, commonly known as biddy- bids plants, can make a cold drink. "You squash it [the leaf] into a jug and pour water over it. It tastes ordinary, but you can put a bit of lemon balm or lemon rind into it. It's good for the lymphatic system." Chickweed, dandelion and young plantain leaves can be used in salads or in winter soups. Nettles are extremely high in minerals and chlorophyll, plus have anti-inflammatory and anti-histamine properties.

But don't think about eating them raw and take care when gathering them. "Wear gloves when you pick them. Grabbing them quickly doesn't work," she says, wincing at the memory.

Cooking or steaming nettles takes the sting out of them and this plant can be used in all sorts of ways, including in muffins. "Anything that is deep-rooted draws up nutrients from deep down in the soil, which you can then reuse."

Another of these is comfrey, which some people consider a weed. It too brings up nutrients and can be made into liquid fertiliser.

One of the most well-known "weeds" is puha, a traditional Maori food that's often paired with pork. Periwinkle, the blue rambling flower, can be used as a suppressant ground cover, but buttercups are bad news.

Pretty as they may be, buttercups suppress nitrogen fixing, so get rid of it. Next time you're driving or biking around the countryside; you'll be surprised how many fields are dotted with the yellow flowers.

Lupins on the other hand should be welcomed, because they are nitrogen fixers. Surprisingly, gorses also have their uses.

"You can use them for a nurse crop to plant native trees. They provide shelter for the natives and then the natives grow up and then the gorse doesn't get sunlight and dies off." If you want to get rid of gorse, burning it won't necessarily work. "The seed pops and it's still viable." Another weed that Marilyn can't see much use for, except for its attractive flower, is the arum lily. These are also extremely hard to get rid of, but she has a way.

"Cut the plant off below the soil with a spade, then stick something on top of it, like wood or a piece of iron. Every time it sticks its head up, cut it off again. If it can't get to the sunlight, it will use up all its resources," she says.

"Like everything, if you don't reach for chemical bucket it takes a bit longer, but everyone's a bit healthier for it."


1. Puha is a source of goodness. Also call rauriki, this native vegetable is a good source of iron, fibre, folate, plus vitamins A and C. According to the University of Auckland, it contains levels of vitamin C similar to that of an orange.

2. Dandelions are a valuable plant for human health. These weeds provide vitamins A, B complex, C, and D, as well as minerals such as iron, potassium and zinc. You can add dandelion leaves to salads, sandwiches and use them to make teas. The roots are sometimes used in coffee substitutes and, of course, you can make dandelion wine.

3. Foxgloves are helpful in preserving other species of cut flowers in a vase or stimulating the growth and endurance of garden root vegetables, especially potatoes. The poison is located in the sap, flowers, seeds, and leaves of foxgloves, but the leaves hold the greatest concentration of the toxin.

4. Clover is often used in gardens as a groundcover because it is good for other plants. By drawing nitrogen out of the air and placing it into the soil, it will enrich your flower bed.

5. Lamb's quarters are highly edible. Also called wild spinach, these plants have a powdery-white appearance, which is often mistaken for mildew. It is high in protein, iron and vitamin B. In the garden, its tiny flowers attract hover flies that help control aphids. These flowers are also a good source of nectar for bees.

The links Beneficial-Weed-Plants.html Organic-Gardening/1987-07-01/Good- Weeds.aspx dandelion-000236.htm ~micka.wffps/poisonous.html

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