Everything you need to know about maintaining a healthy lawn
Keeping your lawn, thick healthy and weed free is easier said than done. Lawns tend to create an ecosystem that can be affected by the weather, soil conditions, pH levels, grass varieties, introduced weeds, how your lawn is used and much more. This article provides some practical tips and tricks for maintaining a healthy lawn in New Zealand and keeping that ecosystem balanced.
Weed Control in Your Lawn
Here’s a quick guide on how to make your lawn weed free.
- Preparing to apply weed control products
- Remove any stones, leaves, toys or furniture from your lawn and give it a good raking to pull up any thatch (dead grass). This will give you a good base to work from.
- Mow your lawn 2-3 days before applying any herbicides. Keep the mower height raised a notch or two above normal. This gives time for the cut grass to 'heal' and leaves enough of the weed foliage still intact for the herbicide to act on (herbicides are absorbed through the pores on the leaves of a weed, so it’s important not to remove all of the leaves).
- See the general rules of thumb below for tips on treating new lawns or fine lawns.
- Treating for general lawn weeds:
- LawnPro Turfclean Ultra, LawnPro Turfclean, Turfclean & Green, Turfclean & Green Rapid and All-in-One have been formulated for the control of the widest range of broadleaf weeds in New Zealand lawns.
- To maintain a weed free lawn, we recommend treating your lawn regularly with a LawnPro Turfclean product (Ultra, Clean & Green, Clean & Green Rapid etc) and alternating it with LawnPro Prickle and Hydrocotyle every 3rd or 4th treatment. Treat your lawn when you first start to notice new weeds popping up, this will nip the problem in the bud and stop weeds from getting well established.
- Fertilize your lawn once every spring and then again in autumn. This will improve lawn health and create thicker swards of grass making it harder for weeds to get established. It also changes the pH level of your soil making it more alkaline and less hospitable to weeds (weeds tend to prefer more acidic soil).
- Treating for Onehunga and Prickle weeds:
- For lawns prone to Onehunga prickle weed apply LawnPro Turfclean Ultra or LawnPro Prickle and Hydrocotyle before the weed flowers and produces its prickly seeds which allow it to spread and become harder to get rid of.
- Once under control, follow the recommended process above of treating with one of the LawnPro Turfclean products as routine and alternate it with LawnPro Prickle and Hydrocotyle every 3rd or 4th treatment. Find out more about Onehunga Prickle Weed.
- Treating moss in lawns:
- In spring and autumn apply LawnPro Mossclear to kill moss and its spores. Then scarify to remove dead moss from the lawn and apply LawnPro Lawn Thickener to raise pH and thicken lawn making the area unsuitable to moss growth. View our more in-depth article on how to get rid of moss in lawns here.
- When to mow your lawn after applying a herbicide
- Hold off mowing after application for 2 weeks. If the lawn 'needs' to be mowed sooner, then raise the mower height a notch or two above normal so as not to remove the weed foliage/leaves. LawnPro herbicides take about 2 weeks to make their way down to the weed’s roots. They enter a plant via the pores in its leaves, so it’s important not to remove the leaves too early (even if they look dead), or you risk preventing the killing of the weeds at their roots.
Fertilizing & Thickening
Healthy thick swards of lawn grass are more resistant to disease and drought. Thick lawns tend to out-compete weeds for water and nutrients and reduces the need to apply weed control/ herbicides.
It’s best to fertilize your lawn mid-spring and early autumn every year when lawns are most actively growing. LawnPro has a great range of lawn fertilisers specifically designed for New Zealand grasses and climate conditions. Our most popular products are LawnPro Green & Grow, LawnPro Natural Boost and LawnPro Thickener.
There are a number of insects and grubs that like to feed on lawns. If your lawn is under attack this commonly shows up in the form of brown patches because creatures like grass grub and army worm eat the grass roots and porina caterpillar eat grass crowns.
Insects like ants and cluster flies can also breed in lawns, and then come indoors creating issues, that most people prefer to avoid.
Kiwicare’s LawnPro Protect granulesare specially designed to protect your lawn by killing pests on contact, and it also creates a protective barrier at the soil surface. If using the product as a preventative it’s best applied in late summer and autumn. However, if you spot pest activity, it’s best to treat your lawn as quickly as possible in order to limit damage.
If it is a fungal disease, it’s best to treat as soon as possible with LawnPro Fungus Control then follow up with LawnPro Mossclear to kill any fungal spores.
Wet lawns are most susceptible to disease. If your lawn frequently floods, or is frequently soggy work on improving your drainage. You can do this by forking the ground to reduce soil compaction, levelling out any hollows where water collects and applying gypsum to your soil.
Lush green healthy lawns need water for growth. However, the water is taken up by roots and not leaves; wet leaves promote disease and shallow water evaporates off before roots can absorb it. When required water should be applied so that it seeps deep where deep rooting grasses can reach it and it will not evaporate off.
When required, water lawns thoroughly in the morning or in the late afternoons/early evening. In very hot conditions, water late in the day once the sun has gone down.
It is better to water thoroughly once, rather than several times lightly. The easiest way to do this is to set up a sprinkler on your lawn and move it to a new area every 15 to 20 minutes. While this might feel like you’re using a lot of water, you only need to water your lawn like this once or twice a week. It’s also more environmentally friendly than doing daily superficial waterings where the water rarely makes its way down to the roots and there is a lot of wastage.
Giving the lawn a good mow, can make your garden look remarkably neater and more put together… And if you have a thick lush lawn - it can give you those much-desired lawn stripes that will drive your mates green with envy. But, did you know that mowing at the wrong height or with blunt blades can damage the health of your lawn? If you’re going to put the hard work in to get a great lawn, don’t let mowing be the thing that lets you down.
The best blade height for your mower
- For fine browntop/fescue lawns - mow at 20 mm.
- For ryegrass lawns - mow at 30-35 mm.
- Never mow off more than 1/3 of the height of the grass.
- When preparing to treat your lawn with herbicide, 2 to 3 days before treatment, mow your lawn but set the mower height a notch or two above normal.
- Raise the mower height a notch higher than normal for the final cut of the year in autumn/winter.
Mulching lawns (leaving the clippings) is not recommended; the dead grass becomes a place for disease spores and weed seeds to survive and although the mulch will supress some weeds it will also supress grasses. So, collect clippings when mowing and dispose of them in your compost or green waste bin.
Ensure your lawn mower blades are sharp and clean. Blunt lawnmower blades damage the grass leaves leaving ragged edges that will brown off and are more susceptible to disease.
Some general rules of thumb for lawn management
- Fine lawn grasses are more susceptible to chemical burning from herbicides. If you have a fine lawn and treat it with a herbicide, you may see some of the lawn turning brown as the lawn goes into shock, but it will generally bounce back to full health in a few weeks (assuming you’ve carefully followed the instructions and haven’t applied at too strong a rate). If you’re worried about treating a fine lawn, we recommend applying your herbicide at a slightly diluted rate for example at ¾ strength.
- Selective herbicides for lawn, kill weeds, but not lawn grasses. That being said if you have cotula, dichondra or buffalo grasses or lawns where clover is being encouraged check the packaging before applying the herbicide to make sure it’s safe for these particular lawns.
- If you have a new lawn less than 2 to 3 months old, it’s best to manually pull out any weeds making sure you capture as much of the roots as possible until your lawn is established enough to handle being treated with chemicals. For lawns that are 2 to 6 months old, it’s best to use herbicide at half rate as the new grass is still sensitive.
- Avoid treating your lawn with chemicals on particularly hot days, or when the UV levels are high as this can cause burning and damage to your lawn. It’s best to wait until a cooler part of the day such as early morning or late afternoon when your lawn is not so stressed.
- Do not apply chemicals to your lawn if the temperature is below 10°C or above 30°C.
- Avoid treating your lawn during periods of extreme stress, e.g. during a drought as this can lead to damage.
- It’s best to apply weed control products / herbicides in spring and autumn as they are most effective when lawns and weeds are actively growing.
- Do not apply products to your lawn if you are expecting rain in the next two hours, or if your lawn is wet and soggy. LawnPro products need approximately 2 hours to dry and stick to your lawn in order to be effective. The addition of water during this time will reduce their effectiveness.
- The sooner you deal with weeds, the better. It’s also significantly easier do regular treatments to maintain a weed free lawn than it is to treat a lawn where the weeds have gone to seed and are spreading out of control.