Garden Myths

There is a lot of misinformation out there about gardening and lawns. Much of it has become folklore and is repeated by people who have heard it and just taken it to be the truth. Some of it is so entrenched, that even garden show gurus have repeated it as garden gospel. So are you ready to have your doctrine challenged? Check out these myths and see if there isn't one which you thought was an 'honest to goodness' fact!

Myth Number1:

Mulch mowing (i.e. mowing the clippings into the lawn) creates thatch.

Fact: Returning clippings to your lawn makes it healthier because it feeds the soil, recycles clippings and saves time. Lawns vary in thickness and vigour, so it is not always practical to mulch mow. Your lawnmower may not have the power needed to cope with the extra load which this method inflicts on it. Or you may have to go back to using a catcher or side discharge with a utility mower or ride on mower at those times of the year when the lawn is most vigorous. But mulch mowing will only do good for your lawn, even if you only do it every now and then. If you need convincing, do a web search on mulch mowing and thatch.

Myth Number 2:

Citrus peel and onions are no good in your compost

The worms will boycott your heap because of all that acid and the citrus takes years to break down! I even heard this one on a prominent TV Australian gardening show; one which I enjoy watching.

Facts: I have a compost heap which is full of worms. When I recently threw in half of a lemon which had been juiced, the worms actually congregated in it - as seen in the photo on the right. In three days there was hardly any evidence that it had ever existed. Both the worms and the microbial bacteria had consumed it.

I constantly place citrus and occasionally onion peel in my compost. It always has loads of worms and there is never anything which doesn't break down. The important things to remember about compost are that it should be moist but not saturated. It also needs air. Lawn clippings placed in shallow layers in between peelings and other material help to heat the heap up, which accelerates the whole process of decomposition. And if you kick off a new heap with some worm laden compost from the previous lot, it will have a head start with micro organisms and worms which will get to work.

Do all of the above and your heap will be aerobic and alive. If your compost heap stinks and is slimy, it is anaerobic and not working effectively. In those circumstances some items would take longer to break down, leading to this misconception. There are a lot of sites on the net which go into great depth about this wonderful topic.

Here is that piece of lemon after one day, with a worm party taking place

Myth no. 3:

If you have clay it means you have lousy soil.

A lot of people see clay as an infertile, soggy, useless medium in which it is unlikely that plants or lawns will grow or prosper. If your drainage is poor, then clay soils can hold too much moisture, which can be a problem; but this is a drainage problem, not a soil problem. Then some people will point to how clay dries out and cracks open when it is dry, developing a hard crust.

Facts: A sandy soil with no clay content will resist wetting, have poor water retention and leach nutrients quickly. Also, if you figure that many Australian soils are clay based, then our native 'gum trees' seem to go rather well in clay, along with a lot of other native flora.

Have you noticed that when many plants' root systems extend down into clay, they actually become well established and can then withstand dry periods? This is because the clay holds moisture and does not leach nutrients. Even when clay cracks open in extreme dry periods, this allows rain water to penetrate deep into the subsoil, after which the cracks close up and seal the moisture in.

Clay soils can be improved by adding organic matter such as compost and animal manures. You can also add gypsum to clay so that it breaks up and forms a clay loam with a more friable structure. Clay soils also benefit from mulching so that the surface remains moist and soft.

Myth no.4:

You can't mow wet grass

Some people consider that wet grass won't cut properly and that it is bad for the lawn.

Facts: Unless you have a golf course and want to prevent spreading fungal diseases from one area to another, mowing a damp lawn is no worse than peeling wet vegetables. The grass will cut fine. Grass may not throw all that well into a catcher, though this will vary between mowers. You will also have a mower which will need cleaning. But at least the lawn will be mown! The real issue is how saturated the soil is. If it is not leaving deep, muddy wheel tracks, then mowing wet grass will do no harm.

Myth no. 5:

Weedmat stops weeds.

This is a product which has been widely used, with the belief that it will prevent weeds from growing, while allowing moisture and air in.

Facts: Weeds, especially couch, actually penetrate Weedmat and will weave through it, making it harder to remove the weeds (see photo). Then weeds also grow in the broken down mulch on top of the matting. It is not at all effective and actually makes it much harder to maintain. I have ripped out several metres of the stuff when fixing gardens with chronic weed problems. What is needed is regular weeding and weed control, combined with mulch on gardens. This will prevent weeds from becoming a problem.

Myth no. 6:

Groundcovers prevent weeds

You will even hear gardening experts re telling this myth without qualifying their statement.

Facts: Groundcovers can reduce weeds, but they certainly don't stop them. Weeds often grow through the middle of groundcovers and present a greater problem than if there was no groundcover at all. This includes couch, Kikuyu, nutgrass, onion weed and Asparagus Fern; all of which will grow right in the middle of most groundcovers and make the garden look unsightly. The trouble is that if you spray the weeds, you have to also spray the groundcover. Hand weeding is also impeded by groundcovers. Again, the secret is to do whatever it takes to access the weeds so that they can be treated or removed, before they become established and spread. Sometimes it is necessary to rip out the groundcover completely in order to deal with a severe weed infestation.

An image of a basket case garden. You can barely make out the Juniperus groundcover in the midst of all the invasive Asparagus fern.

Myth no. 7:

Native plants are tougher and don't need maintenance

There is a commonly held belief that 'natives' can be planted and then given very little attention; after which they will continue to prosper. Somehow they are supposed to be tougher than other plants.

Facts: A native plant to one area of Australia is not a native to all other areas of the country. Plants which occur naturally in your area may do better in your garden, though they may require conditions which resemble those of their natural habitat eg. soil. However, natives are just plants and their hardiness and adaptability varies in the same way that it does for exotics. Bear in mind that a plant from W.A is an exotic on the east coast, where soil and climate are different. Look at each plant based on its merits. If it fits in well with your garden, then consider including it.