Grasses (Graminoids) are an amazing family of plants, including wheat, sweetcorn / maize, bamboo, papyrus etc. We depend on them for so much of our food and other needs. Of course, for this course we are interested in types of grasses that make a good lawn. Just as there are many different families and species of grass, there are also a variety of grass types to use for lawns.
To understand about different types of grasses and how to care for them it’s useful to know a bit about biology. Notice that grasses only ever have 3 leaves, one is dying, one growing and one mature. Keeping this constant cycle of leaves growing and replacing themselves is the aim of good lawn culture. Although you can’t make an individual grass plant produce more leaves (and therefore thicken up a lawn), there are several ways that grasses can thicken up. Some grasses can produce new daughter plants either by creating stolons, or overground stems which then create a completely new plant. Or by creating rhizomes, or underground stems, which will similarly create a new plant. Grasses such as fescues can spread in this way and steadily thicken up a lawn. This is also a good way to protect against stress such as drought and to recover afterwards. On the other hand, some plants can’t spread in this way, e.g. perennial ryegrasses. These plants thicken up by producing new shoots from the same growth point (or crown), these are called tillers.
Although there are lots of different types of grasses, only a few species are suitable for creating good lawns in our climate. Even with those, only some special varieties are worthy of use for lawn creation. These special varieties or cultivars (cultivated varieties) are bred for the purpose and exhibit special tolerance to common diseases, wear well and have visual characteristics which we enjoy.
We choose varieties based on special characteristics they have proven in trial, such as disease resistance, greenness, fineness of leaf, tolerance to drought, etc. As a member of the BSPB (British Society of Plant Breeders) Westland works in conjunction with the STRI (Sports Turf Research Institute) to continually test and compare new grass varieties. For lawn use, varieties are measures for their shoot density (how thick a lawn they create), fineness of leaf, slow regrowth, visual merit, resistance to red thread disease, cleanness of cut, winter greenness and summer greenness. A good score across these parameters indicates a really good variety which will help create a great lawn.
Here we see a photo of the grass variety trials taking place in Bingley, West Yorkshire. The varieties are grown in replicated plots over several years and continually assessed for specific parameters. On this photo we can see some of the variation in greenness by autumn. These factors can vary across seasons and years, so trials have to continue for long periods.
Once we have identified good varieties, we identify good blends of varieties which will create a really good lawn..
In our trials we are continually looking at the varieties and mixtures of varieties we currently use vs potential new varieties and mixtures. We also compare our blends to the mixes of other suppliers. We look at aspects such as germination success and speed, vigour, disease resistance, greenness, winter hardiness, etc.
A common blend is a mixture of PRG and CRF (in a blend 60% PRG to 40% CRF w/w in the mixture).
We have grown some special trays showing some of our lawn mixtures and some of the other blends that are available to illustrate some of the differences….We can do all sorts of detailed studies here including comparisons of germination times and times to reach a good lawn, also studies to check on vigour of re-growth = mowing.
Here we see some of the trays of grass seed we have grown, which allow us to closely compare one with another. The differences are very clear to see here between different grass types and between good and poor mixtures.
We can work through from poor to good and then compare the best and worst – this helps understand how it is possible to score and grade different mixtures and choose the best possible mix.
Once we have decided which varieties are needed, we have to source high quality, fresh seed. For the sorts of volume that Westland uses, this is only available by having it specially grown. At Westland we source grass seed from across the world, but especially the USA and Europe. Grass grown for seed production has to be specially grown and carefully inspected and certified before it can be sent to us. Turfgrass is grown in a very similar way to wheat, and much of the same machinery is used in its cultivation, here we can see a seed drill placing the seeds.
Here we can see the fescue turf grasses in the field, and in the second year of growth. Some seed might be produced in this year, but the majority will only be harvested in the following year, so the crop takes 3 years to yield its full harvest.
Here are the immature grass heads, with yellow anthers spreading pollen in the wind.
Here we see ripening PRG grass Seed. See how the seed head on a PRG changes as it dries.
The final harvest of grass seed, where the grass has been cut down and left to dry naturally. It is then combined to gather the precious seed.
Different grass species and varieties produce different sized seeds. So we need to know the density and seed count in order to know how to blend and pack them. This is an important part of the work we do in our Alconbury Seed Laboratory.
We compare the merits of the main species used for our multipurpose grass seed, as you can see in this table.
These are some of the top performing varieties of PRG and CRF we use in our mixes.
We also use some other species of grasses for special blends. Sheeps / Hard Fescue and also Smooth-Stalked Meadow Grass are components of our shady seed mixes.
Chewings Fescue is a very fine leaved species great for fine seed mixes. However, it doesn’t stand wear and mistreatment very well so we don’t use it in multipurpose blends.
At Westland we have our own seed germination testing laboratory and our own fully qualified seed analysts. Marie and Cherry test every batch of seed which comes into our factory and make sure it meets our exacting standards. We demand extremely high germination levels of 95% and upwards, to ensure that consumers get the best possible results.
We use a whole variety of seed coatings across our seeds business (remember that we also own Unwins and Marshalls Seeds), and have specially selected some of these for use on grass seed.
Gro-Sure grass seed is coated with a blue seed dressing. A dressing is applied as a damp powder and then dries and sticks to the seed coating. This performs a whole variety of functions such as providing micronutrients essential to seed germination, seaweed growth hormones to stimulate vigorous growth, and the blue colouring means that you can more easily see where it has been sown and it also deters birds from eating the seed. The saltiness of the coating also helps, as it makes it taste undesirable to birds.
To Gro-Sure Smart Lawn Seed, our most premium mix, we also apply a very special coating, which we call Aqua-gel. This contains a super-hydrating polymer which holds onto up to x400 its own weight in water.
The Aquagel coating helps store water in the soil immediately around the germinating seed. As the seed is watered or rain falls, the coating absorbs and holds onto water so that the germinating seed doesn’t run short and the long and complicated process of germination can proceed successfully.
To create a blend we carefully select varieties which are good at dealing with the particular problem being tackled. For example, varieties which cope better than average with shady conditions or with the wear and tear of a family lawn. Multi-purpose mixes are a good general mix of all characteristics.
In our trials we can closely examine how different seed blends look and whenever we identify a way to improve our mixes we do so. It is often surprising to see the differences between the speed of germination and especially the final appearance of the lawns produced using the seeds. What grows in the end is dependent upon what varieties and species are included, and their special characteristics and suitability for UK lawns.
The simplest situation to create a lawn is when there is bare earth, ready for seed sowing or for rolled turf to be laid. However, this is an extremely rare situation, and usually some preparation is needed.
It’s really important before you start sowing seed or putting down turf to take a good hard look at the situation and conditions. If there are particular problems then it’s always better to sort them first than to try to rescue a hopeless situation afterwards.
Good soil is a mixture of the three basic mineral elements, clay, silt and sand. When mixed together these make a substance called loam, which is great soil which holds onto moisture, drains freely, contains lots of nutrients and grows a great lawn. You can improve the soil to make it more like a perfect soil.
Sometimes, the soil contains the correct types of particles and nutrients, but has just become too compacted. In this case the missing ingredient is air. The only way to introduce this is to dig over or cultivate the soil, perhaps digging in grit / sand or added organic matter at the same time.
The close conditions around a grass seed are vitally important to focus on – fine particles which provide a steady supply of water, plus a structure which allows excess water to drain away are ideal. Gro-Sure Lawn Seeding Soil is expertly designed to provide just the right conditions for seed germination. Other components such as nutrients and soil compaction are important to consider.
There are a few key reasons why grass seed doesn’t establish properly. The leading cause inadequate watering. Watering to keep the soil moist around the seed is vital – some professional greenkeepers even put polythene sheets over newly sown areas to preserve moisture. This may be an opportunity to ask about whether the customer has the means to water the lawn – hose and sprinkler. It’s vital that the lawn gets water at this stage.
Forget to water it – expect it to die!
Some golden rules of mowing
Frequency of mowing is important to get right – the correct frequency is probably it is more often, particularly in the growing season than your customers might expect. Since weather has a huge impact on how well the grass grows, we can only give a rough guide to mowing frequency, but this chart gives a rough idea of how it changes across the year. In the end, how often isn’t really the point – its about maintaining the right height and not letting the lawn get too long to mow it in a healthy way.
Getting a neat edge to the lawn improves the appearance markedly – use a half moon to create the edge and a pair of lawn edging shears to maintain it.
75% of people with a lawn never feed it. The result of not feeding the lawn is that grass simply doesn’t get the nutrition it needs, it yellows and thins, it starts to be outcompeted by weeds which can grow better in low nutrient conditions (such as clovers, see above). Diseases starts to take hold, such as red thread disease, the lawn becomes weaker and the composition changes from faster growing quality grasses to tougher, weedier grasses. The appearance deteriorates as the number of plants that can be supported per unit area decreases, and the lawn starts to become more difficult to manage.
Getting the right type of feed is one part of the job – applying it according to the instructions is also necessary. Here we see an example of where a lawn feed hasn’t been applied to the whole lawn thinly and evenly. The product has been over-applied in stripes but completely missed from large parts of the lawn, creating a very uneven result. This consumer is very lucky not to have scorched the lawn.
The nutrients that a lawn feed supplies are essential for the proper functioning of the plant. For example, nitrogen is an essential building block of protein, which itself builds the structures of the plant, including leaves and leaf structures. Without enough nitrogen therefore, the plant just doesn’t have the resources to grow well and yellows as the number of photosynthesising structures reduce. Reduced amounts of P and K mean that the plant can’t transfer energy and resources around the plant well, so performance drops and growth slows down. NPK are like the petrol, the oil and the water for a car, keeping all the various chemical processes running at a highly efficient rate.
Knowing if your soil has enough nutrients in it, or has the right conditions for good grass growth is sometimes quite difficult. The ultimate test is to get a soil analysis done, which will tell you about all of these aspects. In the absence of this it’s worth measuring the pH (DIY kits are inexpensive and are probably sold in your garden centre). It’s also a good idea to understand how long the lawn has been down and whether it was fed or not. Lastly, it’s vital to get a good look at the lawn itself. A nutrient poor lawn will be fairly obvious once you understand what to look for. The presence of lots of weeds, especially members of the clover family helps tell you that the lawn needs more food, especially nitrogen. Clover plants can make their own nitrogen in special root nodules, so can then outcompete neighbouring grasses which can’t access any more nitrogen.
The nutrients in a given soil will gradually be released to plants as the soil weathers, which is the normal process of nutrient release. However the chemistry, structure and biological activity of the soil will all change how much nutrient is released and when. Additionally, many nutrients can be in the soil, but locked away in forms that are unavailable to plants. Phosphorus is commonly very rich in soils, but not easily available to plants. Some nutrients are also more soluble than others. Nitrogen compounds, for example are generally very soluble and tend to get washed away out of the soil by rainfall and irrigation. These nutrients are then completely lost to the plants. The biggest source of loss of nutrients is the fact that in order to grow, grass takes up nutrients. As we mow our lawn we chop off large amounts of these leaves and so the nutrients are taken away from the lawn, rather than returned to the soil as the leaves die and decay, which would be the natural process. This export of large amounts of nutrients as we mow the lawn is the main reason why lawns need to be fed.
Work through the product NPK’s, explaining that the high nitrogen classic FWM is for occasional (2x per year) use and must be left minimum 6 weeks between uses. It provides lots of nitrogen for a lovely green lawn. However, due to the high nitrogen it must be watered in within 48 hours, and if over-applied can scorch. Aftercut 3 Day Green is a low NPK 3-1-3, and therefore it’s much less likely to scorch, so doesn’t need watering in. It can be applied every 3-4 weeks, which gives a regular steady supply of nutrient for the lawn. This is similar to how a professional would feed their turf. Aftercut Autumn All in One is different – it has a high K formula, which helps toughen up the lawn for winter weather and wear. Therefore, the same nutrients are needed, just in different amounts as the year progresses.
One of the problems gardeners often have is that over time the lawn thins out and yellows and nutrients reduce, the soil can’t support so much grass growth and the plants gradually die. Feeding the plants which are left will help a lot, but it is also important to fill the gaps and thin areas so that the lawn really thickens up. Over-seeding with lawn seed is a great way to do this, but we have also developed a product called Aftercut Lawn Thickener to feed and seed all in one treatment.
Autumn lawn feeds contain NP and K since all plants needs these key nutrients for healthy growth. However, they are higher potash to encourage ripening of foliage which helps grass withstand winter weather. Since grass grows much more slowly in autumn and winter it can wear more heavily as pets, people and machinery travel across it. This can create big problems in getting the lawn back to good health in spring. These treatments can’t prevent a lawn which is abused from being damaged, but they will help reduce the damage and give the lawn a flying start in spring when the weather improves and growth starts again.
Basics – before just selling any lawn food, it’s important to know a bit about the lawn – feeding just can’t fix every problem. Knowing a bit about the state of the lawn will help identify the right product for that lawn and for that person. A very bad lawn with large brown or bare areas isn’t just going to get fixed by adding some plant food. A lawn in this state needs to be re-established and re-sown or re-laid.
A good lawn needs to be fed to maintain the high quality and rate of grass growth. A product like Aftercut will help keep the nutrient levels high, the grass green and growing and the weeds and moss out.
A lawn in need of help needs a more considered approach – patches might need some seed sowing, weeds might need destroying, etc. We will look at the various products and methods that might help fix these problems shortly.
Scarifying is the process of removing the dead and decaying material from the lawn, helping to remove thatch which can build up over time and reduce the vigour and appearance of the lawn. Raking out thatch with a lawn rake is effective, but a lot of work, especially if the lawn is big. It is also possible to hire out or buy scarifying machines which do a very quick and effective job, although the results can be very scary. In professional situations such as golf courses scarification is a regular part of the routine to maintain the health of the sward, but they need big machinery
Thatch is the undecomposed remains of the lawn grasses. All lawns will contain some thatch, since it is a normal part of the cycling of nutrients back to the soil from the grass. However, sometimes if the process of breakdown is slowed or stopped for some reason, this dead grass matter will build up and up. It separates the grass plants from the soil, makes the lawn spongy and can be a reservoir for lawn diseases and pests. It will then impact the vigour of the grass growth.
The key tools for tackling a thatch problem are shown here. Removing the thatch is only the first part, however you do it. Once the thatch is removed it helps to put down some lawn and Turf Dressing to even out any small bumps and hollows. A gentle feed with something like Aftercut 3 Day Green will help perk up the grass that is left and get it growing stronger now it has been released from the thatch smothering it. Adding more grass seed will also be a great idea – to put lots of vigorous new life back into the lawn.
Aerating the soil can be done most simply with a garden fork, but this can be really hard work and isn’t necessary most effective, particularly in very wet soils. Also, this tends to just squeeze the soil around the newly made holes slightly more tightly. A better solution is to use a hollow tine aerator, which removes small plugs of soil. Alternatively, you can hire a machine to do this job. It’s scary but very effective!
The tools you need for aerating are an aerator, then something to fill the holes with, to prevent them closing up again and to maintain the newly created drainage channels. Sharp sand is perfect for this. Grit isn’t such as good idea as this can damage the mower blades. Adding more lawn and turf dressing to even out the surface again and also adding grass seed will help the lawn recover well from its rejuvination.
Top-dressing is about adding some specially formulated fine soil (usually it is very sandy and free-draining) to the surface of the lawn. This helps fill in any little hollows and gets good soil around the base of the grass plants again. Here we see top-dressing being applied when a newly turfed lawn has been layed – which helps fill in the cracks between rolls and knits in the grass.
For top-dressing, the key tools are some lawn and turn dressing and a way to distribute the material evenly over the lawn, such as a stiff broom. Adding lawn seed with top-dressing is a great idea to improve the results.
This is a simple process that we’ve already mentioned several times. It’s as simple as spreading more grass seed over the whole lawn, paying particular attention to thin or bare patches. Since 25% of the grass in a lawn dies every year it’s a really effective way to keep a lawn looking great. Treating the whole lawn will help ensure that and differences between the appearance of the established and newly grown grass are reduced.
The obvious tool for this job is quality lawn seed, but adding seed together with some lawn and turf dressing will help establishment and will also help distribute the seed evenly over the lawn by bulking it out.
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