Ideal Lawn Care for Weed Grasses?
Weed grasses can be tough to manage in domestic lawns. Minimising their opportunity to thrive, rather than complete eradication should be a realistic objective when working with a lawn care service rather than unrealistic complete eradication. Read on for our top tips for the control of weed grasses in your lawn
Weed Grass in Lawns - Our Top Tips for Control
Have you noticed different types of grasses within your lawn recently? With the welcome return of good growing conditions comes the seasonal burst of annual meadow grass (Poa Annua) along with other seasonal shallow-rooting meadow grasses. These grasses can lead to a lawn appearing patchy and discoloured with several grass types present. The management of weed grasses is an ongoing battle for greenkeepers and grounds teams. In the absence of a chemical control that will differentiate between difference types of grass - management is the key word.
Where are these Weed Grasses coming from?
As with many seeds, weed grasses can be spread by birds, and can lie dormant in the soil for a number of years. Even turf growers will not guarantee against some annual meadow grass - it can be that invasive. Cheaper top soils and top dressing may contain seeds if not sterilised.
Poa (as known in short) is a very different grass as it has a very short lifecycle. This plant is shallow rooting; it knows its days are numbered should we get a dry spell so it works to produce seed heads quickly at the first sign of drought stress, allowing this weed grass to spread further.
Unfortunately, the entry point of weed grasses cannot be stopped but as ever with any other weed or moss, maintaining a dense grass cover through regular lawn treatment and occasional lawn renovation will make your lawn less susceptible and easier to manage.
Weed grasses are common across far more intensity managed turf areas (such as golf greens) than lawns. Unfortunately embracing a level of this in your lawn is something you may have to do - but we can still tip the balance in our favour!
Our Five Top Tips for the Control of Coarse Grasses
1 - Regular Mowing
Mowing more frequently at a height of 25-35mm will complete a dual job of helping the desirable grasses in your lawn to thicken and thrive and allow you to mow out a number of the seed heads being produced. Be aware that many weed grasses are smart to this and will flower at increasingly low heights of cut. Don’t let the perfect be the enemy of the good with dropping your height of cut too low. Consider brushing your lawn prior to cutting in order to cut out more of these seed heads.
2 - Verticutting / Light Summer Scarifying
We typically advise against the scarifying of lawns through summer months, but this depends on the severity of the work. Many domestic lawn rake type machines can be useful tools in combatting meadow grasses to mechanically (or manually via a rake) remove or weaken them. This light thatch removal will aid desirable grasses. As our friend Robbie Lynn at Premier Lawns shows in this video, he has a few methods of digging out, or teasing out weed grasses during the summer months, including Lawn Scarification. It is important that too much material isn't removed through summer months as this also acts to keep evaporation rates from the soil low and your grass green through summer. Again, this is about management rather than perfection.
3 - Fertiliser Inputs
By not feeding your lawn or not using enough fertiliser through ad-hoc, irregular application, the desired rye and fescue grasses in your lawn are not going to be able to thrive. With this, weed grasses will be able to compete in thin or weak areas of your lawn.
Shallow rooting weed grasses also benefit from too much fertiliser. By applying too much fertiliser, or using quick release products and at the wrong time of year, you will be encouraging everything to grow too much and give yourself a great deal of mowing! Weed grasses thrive off over applications. The best feeds to be applying to lawns contain slow-release food sources, which are part of a calculated plan, rather than ad-hoc applications. Our lawns thrive off a fertiliser input of 110-130kg of Nitrogen per Hectare per year - that’s 110-130g over 100m2 of Nitrogen. Over many years we have found that this is the ideal place to be in terms of fertiliser input to gain the best return from a lawn treatment service.
This is applied in a range of slow release, compound, semi-organic and organic forms to provide nutrition for lawns when it needs it, not more or no less to avoid excessive meadow grasses and disease, such as Red Thread Disease.
4 - Aeration and Scarification
We need to promote better growing conditions for the rye and fescue grasses that we wish to promote for an attractive lawn - there could be a number of reasons as to why this isn't successful for a number of reasons - for example a leatherjacket infestation or it could be excessive shade. Lawn Renovation is a process of:
- - Scarifying the lawn aggressively - thereby clearing out a great deal of shallow rooting grasses, thatch and moss
- - Mowing the lawn as a lower-than-normal height, hoovering out debris
- - Aerating the lawn - creating better soil conditions for desirable grasses
- - Overseeding the lawn, improving the percentage of desirable grasses.
This mechanical work will help to reduce weed grasses, while providing wide ranging benefits to your lawn. It's the ideal course of action for your lawn in many cases.
5 - Manual Removal
As we recommend with difficult to control weeds such as Speedwell and has been seen from Robbie at Premier Lawns, taking a knife to areas of turf is a good option when just an isolated area. It is important that the whole of the plant is removed, and maybe more applicable to rough stalked meadow grass as annual meadow grass will have already dropped seeds. Much like hand weeding borders, this is unfortunately the sure proof way of removing the current crop of annual meadow grass.
Weed Grasses - Our Thoughts
Weed grasses unfortunately cannot be eradicated. Poa will grow at very low heights of cut and in nearly all soils when conditions allow - even on golf and bowling greens. Rather than seek unrealistic complete control, we should look to manage and embrace annual meadow grass in particular. This should be through caring for our lawns with a sustainable fertiliser programme in combination with mechanical / manual work for the best possible lawn health. Our efforts targeting weed grasses should be sustainable as they are here to stay!
If the desirable grasses in your lawn need a lift, or if the volume of weed grasses demand more aggressive work, you can speak to us on 01827 826123 for more information on how we can help, or complete our contact form.