Timing is critical to rid your lawn of this year’s crop as effectively as possible, in turn reducing the seedbed for next year’s crop. Once a weed flowers (for example, the daisy-like flower on Capeweed), it is getting a good foothold for not just the current year but for years to come.

SPRAYING TOO EARLY

An application of broadleaf herbicide in May/June will give you a lovely clean lawn surface throughout Winter, but may run out before the end of the weed season in late Spring. This is fine if your budget allows two sprays annually. I prefer to spray from July onwards, so only one application is necessary. While your lawn will have some weeds during early Winter, a single application can only be good for your budget and the environment.
It is important to use a product that has initial knockdown quality as well as a residual property to prevent yet-to-germinate weeds. These products are generally not available to the public. You can purchase Bromoxynil-based products at your local Hardware or garden centre but, in my experience, these products are initially effective but have a relatively short control period. This means repeated applications during a broadleaf weed season that can be up to 6 months long, effectively costing you just as much, if not more in the long term. So choose an operator familiar with the need to apply a product with the two qualities – an effective knockdown and a generous residual control period.

SPRAYING TOO LATE

Waiting until September or October to clear out weeds can be a problem. Weeds such as Capeweed, Clover, Cudweed and Flatweed can spread out not just as individual plants but as a ‘team’ to really choke out a lawn. Removing these late in the season can leave sparse, pitted areas that require work such as top dressing and repeated fertiliser applications through Spring and early Summer to encourage lawn growth back into these areas.
Prickly weeds such as the dreaded Bindii/Jo-Jo will set a nasty flower (prickle) in mid-Winter that should as a general rule be sprayed out before mid-Spring. Do not let it seed at all. Yes, you can kill it anytime but spraying out Bindii/Jo-Jo in October/November will just release the prickle from the dying plant, leaving it to roll/blow around your lawn until it gets picked up on your feet, your kids’ feet, the pets or finally the lawnmower.

FREQUENTLY ASKED QUESTIONS

What if it rains after you’ve sprayed my lawn?
Spraying leaf-absorbed products during rain and wind can be tricky. In my experience the wind is a bigger foe than the rain. As far as rain goes, there are extremely effective surfactant/sticking agents around to bind products to weed leaves and dry the product quickly when rain is imminent. I find products that are properly blended with the correct sticking agents are effective even when it rains within an hour after application of the herbicide. Wind however is difficult to counter. You can use shrouded booms but these are a little risky as it is hard to keep an eye on the performance of nozzles (eg streaking, poorly functioning tips). Generally I just don’t take the truck out. I prefer to see my golf ball hit the trees than my herbicide.

How long do I need to stay off the lawn after you’ve sprayed for broadleaf weeds? Do I need to keep pets off the lawn? Are the herbicides safe?
Herbicides now undergo stringent pre-release tests to ensure they are safe for people and the environment, and all licensed operators are fully versed on herbicide schedules, their proper handling, application and storage.
My choice of broadleaf herbicide is a Schedule 5 (least offensive), which means it is only slightly toxic. It will not affect pets, and you can walk on lawns as soon as the product has dried. Recently Schedule 5 pre-emergent Wintergrass and Crabgrass products have also become available.
Herbicide application is based around the hit and stick method. This means the herbicide is applied in a mist, and sticks to weed leaves so it can be absorbed by them. This allows for maximum take-up of the herbicide and prevents run-off and leaching into the water table.

SUMMING UP

Weed control is all about using the right product at the correct rate at the right time, in weather conditions favourable for the performance of the product. It is also about persistence.
When I have been spraying a property for 4-5 consecutive years, the weed seedbed is so heavily reduced that spraying is purely a maintenance issue; a bit like getting the car serviced. Without large weeds taking hold each year, your lawn is free to establish fully throughout the year.
Of course, some garden conditions can favour weed development. For example, shaded, worn or waterlogged areas are prime sites for strong broadleaf weed development, and these need to be managed in conjunction with your spraying programme.

If I have heard it once over the past twenty years I have heard it a thousand times.
My answer is “Of course I can but is it really a big enough problem to warrant spraying?”

Every hot season will see some Beetle go from its larval stages to adulthood and yes you will see some, but are they swarming enough to do any damage?

For some reason I hardly ever hear people asking me to spray out their Armyworm, Webworm, Cutworm or Spider Mite. These are seldom seen in the home lawn but their damage is a lot more dramatic than our old friend, the African Black Beetle.

If you observe 50 –100 beetles wandering across your lawn don’t panic. It’s time to panic only when there is more beetle than lawn visible. This is an extremely rare occurrence.

Water repellence

Generally repellence is often misdiagnosed as beetle damage. Beetle damage (on the extremely rare times it occurs) will leave the top growth weak enough to pull out with just a thumb and forefinger. Also remember the circular desperate-looking fungal patches that can come with Spring Dead Spot fungus, or later in the season with Brown patch (Rhizoctonia).

So my strategy is to embark on a two or three-visit programme to re-wet your soil via a quality wetting product.

Wetting agents

“But I have tried a wetting agent before,” I hear you say.
Wetting agents are measured on how quickly they get water moving through the soil profile and how many times they will re-wet after the soil/sand has partially dried out.

Generally off-the-shelf wetting agents have limited effect. The commercial grade wetting agents vastly out-perform the wetters you are able to buy from your local garden centres.

The commercial operator pays for the privilege of using cutting-edge technology and a portion of that cost is passed on to you, the consumer.
In this cost is also the guarantee of having the product(s) applied correctly, giving the product every opportunity to do its job properly, and giving you, the consumer, value for money and more spare time.

In summing up, if you think you have a problem with beetles, make sure you look beyond the surface and ask yourself:
Is your soil wetting up during irrigation/rainfall?
Is your cutting regime (height, cutting interval) consistent?
Are you supplying adequate nutrients on a regular basis?

Many things can damage a lawn surface but extremely rarely will it be the beetle.

Control & Management

The key to controlling Wintergrass lies in its management using both chemical and cultural practices. Good cultural practices means keeping the lawn well maintained by regular mowing and fertilising, and not allowing bare patches to develop which will offer an ideal seed bed for Wintergrass germination.
Light infestations of seedlings may be easily hand weeded as Wintergrass has a very shallow root system.

Chemical Management

There are two main ways of approaching the management of winter grass with chemicals… pre-emergent control, which means spraying the lawn before the weeds emerge, or selective post-emergent control once the weeds have already germinated.

I prefer to use pre-emergent control for Wintergrass. A common saying is “One year of seeds brings seven years of weeds!” This might sound like an “old wives tale” but in fact, it’s true. Dealing with weeds before they have the chance to seed is the most efficient and effective way to have a healthy lawn. The use of a residual pre-emergent application can also eliminate the need for multiple post-emergent herbicide applications.

Common questions or concerns I hear about using a pre-emergent spray on Wintergrass include the following:

“It is February/March and I don’t have any Wintergrass. It seems a bit silly and a waste of money to spray nothing.”

Some lawns do not have a Wintergrass problem. This may be due to an extremely strong lawn that covers all areas well, with no weak spots. It could be due to good hygiene since the lawn was established, with minimal shade, cool, damp or worn areas. These people are lucky and should hold on to their money and spend it on anything else in the garden!!

However once a lawn situation shows a susceptibility to Poa (Wintergrass) it is a safe bet that it will re-appear yearly (as an annual grass does) and strengthen its hold in your lawn each year.

“Why shouldn’t we just wait until it is all up for the year and kill it then”?

Preventing seed production and plant reproduction are the compelling reasons for pre-emergent weed control strategies, as mentioned above. Wintergrass has an extended germination period that lasts from early Autumn right through Winter and into Spring. A pre-emergent product applied in Autumn kills seed roots and shoots before they emerge through the soil and set a seed head.

Removing Wintergrass (and some weed/grass species) after it has germinated and established still leaves the problem of its root mass underground. The Wintergrass plant (a monocot) has a thick fibrous root system, with the roots running deeper than its height on the surface. If mechanically removed, the roots hold onto soil, leaving pocks/divots in the lawn surface. If controlled with chemicals, the root mass rots underground but remains in the soil, leaving bare areas above which detract from the look of your lawn, and which provide an excellent place for more weeds to take hold.

“I have sprayed pre-emergent this year and had a good result with just a few plants breaking through. So does that mean I’ve won the war against weeds? I won’t have to spray anymore?”

It needs to be noted that a successful season’s control doesn’t mean you have won the war against that weed in that situation. Shaded, worn, sparse and damp areas are prone to annual attacks of weeds (in this case Wintergrass) year in, year out. Vigilance and organisation go a long way towards effective weed control. In areas proven to be a problem, I recommend yearly or twice-yearly control, as do the manufacturers of the various products.

In my experience the best results are achieved by spraying twice yearly for a period of not less than three years. In most cases you can then revert to a yearly application of the product to give satisfactory control. However there are exceptions to this, some clients have enormous Wintergrass problems and twice yearly applications are a must for prolonged control.

“What if I don’t spray at all? Will the Wintergrass die off in the Summer?”

Yes it will. In most cases a prolonged period of 33-35oC will burn the canopy off what is a cool season grass. Unfortunately there are also exceptions to this. Some Wintergrass will persist throughout an entire year, benefiting from reticulation systems being on throughout watering season. Then the problem becomes lawn-threatening as the new germination year plants mix with the older last year plants. The multiplication of plants can lead to dinner plate-sized weeds which choke out the lawn, especially through the cooler months.

“I didn’t use a pre-emergent spray and now its mid-Winter and things are a real mess, Wintergrass everywhere. Is there anything you can do?”

Yes, we can remove mature Wintergrass with a post-emergent product. Unlike the pre-emergent products which offer residual control, post-emergent control is best done during late-Spring when ALL plants are up for the germination year. If post-emergent control is done for the first time, then pre-emergent control is recommended the following Autumn as seeds have set and plants will re-emerge the following year, even though the active population has been cleared out for this year.

Post-emergent removal in the Spring is effective, but can leave the lawn surface with numerous bare patches, pitting and poor turf uniformity as discussed above. Lawn renovation and top-dressing is then often necessary to provide an even lawn surface again.

Mowing mistakes can result in discolored lawn tips, brown spots, and even severe damage to the lawn. Common mistakes are mowing too infrequently and cutting grass too short. Here are some tips on proper mowing technique:

Avoid Scalping

Letting grass grow tall and then removing more than 1/2 the leaf blade is called scalping and can damage the lawn. Mowing grass extremely low can also damage the lawn by cutting into the crown of the plants.

Sharpen Blades

Make sure your mower blades are sharp in order to cut cleanly. Dull blades can shred grass and cause discoloration at the tips because frayed grass blades lose moisture easily. Sharpen/replace the blades of rotary mowers several times each growing season. Reel type mowers usually only require sharpening once a year, but adjust them to ensure they cut cleanly. Some grass species have tough blades, which causes blades to wear quickly.

Be Gentle with Damaged Grass

Raise the mower height a notch or two when mowing a lawn that’s recovering from drought, insect damage or disease.

Don’t Cut Wet or Wilted Grass

Avoid cutting wet grass, which can cause brown spots because clippings clump together and smother your lawn. Cutting wilted grass, particularly during the hottest part of the day, can also cause severe damage to your lawn.

Know When to Mow

The best guide for mowing frequency is the growth of your grass. Plan to cut less than one-third of the grass blade in one mowing. Keep in mind that certain grasses require close mowing to stay healthy. Allowing these grasses to grow too high will promote thatch development.

So You Miss a Mowing?

During periods of rapid growth, lawns may require mowing as frequently as weekly. Sometimes we just don’t have time to mow as often as we’d like. If your grass has grown too high, reset your mower to a higher cutting level. A week later, reset the mower to cut at the normal height and mow your grass again.

Mowing Height

Select the proper mowing height for your lawn. Measure the grass plants after mowing a very small area, then adjust your mower as necessary. Always mow your lawn at the recommended cutting height.
A thriving warm-season grass will tolerate lower cutting heights with greater frequency during warmer months, as leaf production is prolific during October to April, but cutting heights should be raised in cooler months to aid photosynthesis.

Mowing After We Have Sprayed

To ensure the effectiveness of the application and to minimise exposure, the lawn should not be mowed for at least 24 hours following the application or until it has been watered, or it has rained and dried.

Don’t forget your garden watering roster

To find out your watering days, simply take the last digit of your house or lot number and apply it to the table below.

Experts agree these rosters will provide more than enough water to maintain a waterwise garden.

For more tips on how to be waterwise, visit waterwisewaysforwa.com.au or call the Waterwise Infoline on 131039.