Growing A Lawn From Seed In NZ

How To Grow Grass From Seed

This series of articles explains each of the steps involved with preparing the soil ready for seeding, and then how to seed the lawn correctly. You will become an expert in growing grass from seed!

Selecting The Right Variety Of Lawn

The choice of lawn depends on your climate, how much wear your lawn will get, and what look you are wanting to achieve. The Plant Company generally starts with how much wear the lawn will get when recommending a variety. That is, will the lawn have kids and dogs playing on it constantly? If the answer is yes, then Amenity Rye is the best option as other varieties will struggle and end up patchy. This variety is the same as used in most sports turfs around NZ. For limited wear lawns, Tall Fescue or Kikuyu also become options. Fine Fescue lawns do not cope with wear at all.

Climate is the next consideration for choosing a variety. If you live in a coastal are or need a tough grass, then Kikuyu is a great option. However, Kikuyu may go dormant during winter so is not the best option for cooler regions or areas that have a lot of frost. Generally, The Plant Company does not recommend Kikuyu for the South Island. Tall Fescue and Amenity Rye will grow in most environments, including cool climates, but may go dormant (i.e., brown off) during summer if not watered. Fine Fescue is not suited to coastal areas but will grow well in most other climates.

The final consideration is the look you are after. If wear and climate are not an issue, then the most aesthetic lawns will be achieved with either the Fine Fescue or Tall Fescue varieties. Specifics around growing each variety are covered in subsequent sections. Amenity Rye and Kikuyu lawns are still aesthetic but not to the level of the Fescues.

Warning! There is a lot of cheap seed available from different stores and often that seed produces highly variable and often disappointing results. The Plant Company only uses certified seed with greater than 99% germination. Establishing a lawn takes a lot of effort and for most people they don’t have time to do it once, let alone twice. Therefore always buy quality lawn seed.

Growing The Perfect Lawn

The key to a fantastic lawn is all about the preparation before seeding, choosing the right variety, and then looking after the lawn once it has germinated. Each situation tends to be slightly different which is why The Plant Company has put considerable effort into producing articles that detail every step of the process. We want our customers to grow lawns they will be proud of and their neighbours envy. Please refer to our articles Selecting The Right Lawn Variety, Preparing The Soil For A New Lawn, How To Seed A Lawn, and Lawn Weed Control if you are starting a new lawn. If you simply want to tidy up what you’ve got, the article How To Pimp My Lawn would be a great place to start. Enjoy!

How Deep Do I Sow Lawn Seed?

Grass seed typically germinates within the top 10mm of soil. As the planting depth increases, however, the chances of getting the seedlings to emerge starts reducing. Lawn Seed will strike even if applied to the soil surface provided it does not dry out. Therefore, when seeding an area, The Plant Company recommends only a gentle raking. Some seed will be mixed with the soil and some will be exposed on the soil surface after this task is complete. This is normal.

How Do I Know If My Soil Is Too Compacted For Seed To Germinate?

Checking to see if the soil is too compacted for lawn seed to germinate is essential for establishing a lawn successfully. The test involves taking a garden fork, holding it at waist height, and then dropping it. If it digs in, the soil is fine to seed as compaction is not evident. If, however, the fork falls over, the ground is too compacted and needs to be worked up to get the seed to strike and take root. This test is vital for lawn success and should be repeated across the area to be sown. It is also a good indicator of whether an established lawn needs to be aerated. NB: a dry lawn can be hard and give misleading results. The lawn should therefore be moistened several hours before doing this test.

How Long Before My Lawn Appears

The time for a new lawn to appear depends on the temperature. During summer, a green tinge will be evident after just a few days. A lawn sown in winter can take three weeks to be at the same level. The Plant Company advises sowing lawns anytime from mid-spring until mid-autumn to coincide with the warmer temperatures. Please also note, that the faster a lawn establishes, the less weed pressure there is likely to be. See our articles on Preparing The Soil For A New Lawn and How To Seed A Lawn for great information on getting a lawn underway.

How Much Lawn Seed Do I Need?

The answer to this question depends on the variety, whether you are seeding a new lawn or over-sowing an area, and the time of year. The Plant Company has detailed information about seeding rates for Amenity Rye, Tall Fescue, Kikuyu, and Fine Fescue lawns for seeding both tilled areas and for over-sowing. A buffer of 10% is included for seeding tilled areas and 15% for over-sowing within those recommendations. If you plan to seed during cooler times of the year, The Plant Company recommends allowing an additional 10% buffer. See our articles on Preparing The Soil For A New Lawn and How To Seed A Lawn for great information on getting a lawn underway.

How To Get A Lawn Level?

You’ve got an area worked up and it has a few humps and hollows despite all your best efforts. How do we then get it consistently level before seeding? The first step is to rake it until it looks level. If you have worked it deeply (i.e., greater than 20 cm deep) you’ll need to let it settle for a few days. The best way to speed up the settling process is to water it thoroughly and let the weight of the water act like natural compaction. After it has settled, rake it again, then use a straight piece of timber, about 2-3 m long, and run that across the soil surface like a screed. Keep doing this until you are happy with the levels. This does take some patience but is worth the effort as you will generally be looking at that lawn every day.

If you have a large lawn, you might want to consider using a quad-bike with three old tyres towed behind it. You need to have a bit of speed on so the tyres deflect the high spots rather than riding over them and gouging deeper hollows. You will be surprised at how effective that method is. Do not use a heavier vehicle as this will cause compaction and subsequent germination issues.

The final step is to saturate the soil with a sprinkler and look for any pooling or settling areas. Those are the low spots that need to be addressed with more soil and further levelling. Do not roll the lawn before seeding as this can cause compaction issues. The Plant Company recommends you read the articles, Selecting The Right Lawn Variety, Preparing The Soil For A New Lawn, and How To Seed A Lawn, as the next steps.

How to Grow A Highly Aesthetic Lawn

Tall Fescue and Fine Fescue are regarded as the most aesthetic lawn varieties due to their fine leaves and soft appearance. Fine Fescue has a very fine leaf blade and when grown well, produces turf that everyone will admire. See the article, Growing A Fine Fescue Lawn, for details on how to grow this lawn type well. However, Fine Fescue Lawns are also the most challenging to grow and will fail if they experience wear (dogs and children playing generally) and are not looked after with regards to spraying, fertilising, and watering.

Tall Fescue has a wider leaf blade than the Fine Fescue and also produces a highly aesthetic lawn. In this instance, however, it will cope with slightly more wear than Fine Fescue Lawns. Careful attention to the inputs is also required and this is covered in the article, Growing A Tall Fescue Lawn. Please see the article, Selecting The Right Lawn Variety to determine which variety to use if you are unsure.

The final part to growing a highly aesthetic lawn is to not mow it too low as this will allow weeds to establish and takes away from the lush appeal that makes a lawn stand out. The most aesthetic lawns are generally mown twice per week with a little and often philosophy. Lawn mowing is covered in the article, Mowing A New Lawn.

How To Growing A Hard Wearing Lawn

The Plant Company's choice of varieties for a hard-wearing lawn is Amenity Rye. It forms a lush and dense sward that can cope with a lot of foot traffic and is easy to grow. This turf type is typically used on sports fields across NZ and is perfect where kids and pets will be on the lawn often. Please see the article, Selecting The Right Lawn Variety to determine which variety to use if you are unsure.

To grow an Amenity Rye lawn well, let’s assume you have followed the instructions given in the sections, Preparing The Soil For A New Lawn and How To Seed A Lawn, and now you have a newly struck lawn. After the lawn has been actively growing for 3-5 weeks, put on the broadleaf herbicide, Turfix, and follow the label instructions. It is vital that over-spraying is avoided and label rates are followed to avoid injuring the young seedlings. This needs to be repeated in spring, summer, and autumn for good control of broadleaf weeds. Keep an eye out for grass weeds such as Paspalum and manually remove any of these seedlings as soon as they show. Just use a screwdriver to ease them out and drop a little more seed into the hole if the grass is a bit “thin” in that area. If you followed the recommendations in the article, Preparing The Soil For A New Lawn, there should be few, if any.

Fertiliser is essential for growing a lush Amenity Rye lawn. Therefore, fertiliser for established lawns should be applied during spring, summer, and autumn at low rates to keep the lawn growing actively. DO NOT use urea or any ammonium based fertilisers as they are a common cause of “burning” in lawns.

Amenity Rye lawns benefit immensely from being watered during dry periods. If the lawn is left to dry out, it will start to open up and allow weeds to appear. Remember, the goal is to produce a lush lawn as quickly as possible to suppress weeds. Anything that can help the grass grow will help towards achieving a better lawn overall. Please refer to the articles: Rolling The New Lawn and Mowing The New Lawn for more advice.

How To Prepare The Site For Over-Sowing A Lawn

This article deals with over-sowing a lawn where the soil has not been worked up or only minimally tilled. If you are planning on working up the soil, please refer to our article on Preparing The Soil For A New Lawn. If poor drainage or constant ponding present as problems, this will need to be resolved to achieve a successful lawn and must be addressed first. See our article on Lawn Drainage for more information on this subject. The first step is to kill any weeds and the old lawn using glyphosate and to remove large plant residues. The Plant Company recommends adding Wetcit in with the glyphosate to give it an extra boost and broaden the range of weeds controlled. Any weeds such as clover will not be controlled with glyphosate so it may be necessary to use a contact herbicide that targets the problem weed(s). Do not use Turfix or other lawn herbicides during this preparation phase as they can negatively affect the seedlings as they germinate. For small areas of problem weeds, boiling water can be another option for control.

If it is an old lawn being replaced, The Plant Company recommends mowing the lawn at a very low level 2-3 days after spraying. We do this to help expose as much soil as possible rather than being covered over with vegetative material. You don’t need to chip away the old lawn unless the soil is compacted.

If the soil is heavily compacted, over-sowing will give a poor result. To assess compaction, take a garden fork, hold it at waist height and drop it. If it digs in, the soil is fine for over-sowing. If, however, the fork falls over, the ground is too compacted and needs to be worked up to get the seed to strike and establish. This test is vital for lawn success and should be undertaken across the site. NB: a dry lawn can be hard and give misleading results. The lawn should therefore be moistened several hours before doing this test.

While the lawn can now be sown, The Plant Company highly recommends a little more effort to minimise weed problems down the track. This is particularly important where Couch and Paspalum could be problems. This process involves watering the lawn and getting the weeds to germinate so they can be sprayed with glyphosate. Do this for three weeks with spraying every week is the recommendation. It also gives the opportunity for more levelling to be undertaken. The last spray of glyphosate is the day before you intend to sow. Now you are ready to sow the lawn!

How To Prepare The Soil For Sowing A Lawn

This article deals with seeding a new lawn into worked up soil, or where a 10 cm layer of soil has been applied over an old sward. If you are planning on over-sowing and not working up the soil, please refer to our article on Preparing The Lawn For Over-Sowing. If poor drainage or constant ponding presents as a problem, this will need to be resolved to achieve a successful lawn and must be addressed first. See our article on Lawn Drainage for more information on this subject.

The first step is to kill any weeds using glyphosate and to remove large plant residues. Do this even if you plan on working up the soil and before adding any more topsoil. The Plant Company recommends adding Wetcit in with the glyphosate to give it an extra boost and broaden the range of weeds controlled. Any weeds such as clover will not be controlled with the glyphosate so it may be necessary to use a contact herbicide that deals with the particular weed issue. Do not use Turfix or other lawn herbicides during this preparation phase as they can negatively affect the seedlings as they germinate. For small areas of problem weeds, boiling water can be another option for control.

The next step is to work up the soil to a fine tilth and rake it free of debris and rocks. If the soil is heavily compacted you might need to dig a little deeper but otherwise, we are only focussed on working up the top 10 cm. On sandy soils you might want to incorporate compost which will assist with moisture retention and help stimulate biological activity. Compost is less important on other soil types but can be added if desired. It will help to produce a better result. Tip: If the soil is hard, consider soaking it 24-hours before working it up.

After raking, and to achieve a more level surface, The Plant Company often recommends using a 2m long board to screed the area, much like levelling out concrete. Do not use a roller to level out the lawn as this will create compaction and hinder seed germination.

We now undertake a simple compaction test before progressing any further. That is, take a garden fork, hold it at waist height and drop it. If it digs in, the soil is fine to seed. If, however, the fork falls over, the ground is too compacted and needs to be worked up again to get the seed to strike and take root. This test is vital for lawn success.

While the lawn can now be sown, The Plant Company highly recommends a little more effort to minimise weed problems down the track. This is particularly important where Couch and Paspalum could be problems. This process involves watering the lawn and getting the weeds to germinate so they can be sprayed with glyphosate. Do this for three weeks with spraying every week is the recommendation. It also gives the opportunity for more levelling to be undertaken. The last spray of glyphosate is the day before you intend to sow. Now you are ready to sow the lawn!

How To Seed A Lawn

Having established a seedbed that is now ready to receive seed, the next challenge is how to get the seed on. The Plant Company prefers to keep this simple without the need for spreading equipment unless you have a very large area to seed.

Mix lawn seed and new lawn fertiliser (or soil) in equal quantities in a bucket. Usually, half of the seed will be used during the first application. Walk back and forth across the area scattering the mix as you go. It is important to meter out the mix so it covers the entire area. Now mix the remaining lawn seed and new lawn fertiliser together and walk across the area at right angles to the first pass. The blue colour of the new lawn fertiliser is a great indicator for where the seed is landing. You should see a consistent application of lawn seed and new lawn fertiliser on the ground when finished.

For a large lawn, The Plant Company recommends a seed spreader is used which can be sourced from a local Hire Centre. Alternatively, break the area into sections and meter out the seed accordingly. We would generally spend more money on seed than hiring equipment, but this depends on the size of the area.

Complete the process by gently running a rake across the soil surface. Do this even if you are over-sowing an area. If all your preparation has been done according to the advice in The Plant Company articles, this will be a quick and easy job without the need to move earth around. Please refer to the articles Preparing The Soil For A New Lawn or Preparing The Lawn For Over-Sowing if you are still in the early stage of getting a lawn underway.

Lastly, start to water the newly seeded areas shortly after sowing. This helps bind the seed to the soil and is important for germination to begin. Even if the soil appears moist, The Plant Company advises a light irrigation. Gentle watering should be at least daily thereafter until a green tinge appears across the entire area.

Remember, seed is cheap relative to the cost of rework and associated angst if you get it wrong. The sowing recommendations provided by The Plant Company already have buffers of 10% included so please use all the seed unless you have deliberately over-ordered.

Lawn Seed Quality

There is a lot of cheap lawn seed available from different retailers and often that seed will give highly variable results. The Plant Company has seen first-hand the disasters created with cheap seed. Patchy lawns through poor germination, mixed lawn species, and seed full of weed seeds are the common issues with cheap seed.

The Plant Company only uses certified seed with greater than 99% germination. Establishing a lawn takes a lot of effort and we want our customers to get it right the first time. Therefore, The Plant Company cannot emphasise enough the importance of buying quality lawn seed.

Managing Birds In A Newly Sown Lawn

The reality is that it would take a massive bird infestation to have any effect on a newly seeded lawn. That said, birds will be more of an issue for an over-sown lawn or where the seed has not been mixed into the soil. The simple solution is to offer the birds an alternative food source. The birds are only going for the lawn seed because it is an easy meal. By that logic, The Plant Company recommends giving them an easier meal by deliberately putting out seed each day or some slices of bread. This only needs to happen for 7-10 days while your lawn strikes.

The recommended sowing rates provided by The Plant Company for lawn seed include a 10% allowance for loss to birds. That loss rate is increased to 15% for rates recommended for over-sowing. Actual seed losses to birds are generally less than 5%.

Should I Over-Sow Or Work Up My Lawn For Planting?

The decision to over-sow or work up a lawn is mostly about risk and the effort you want to put into establishing a lawn. Over-sowing is a much riskier option as you are relying on seed to strike with minimal soil around it. The seed is therefore vulnerable to drying out, being eaten by birds, and can result in bare patches that need to be reseeded later. That said, by getting a few basics right, this is often a viable and cost-effective option for establishing a lawn. Please refer to the article, Preparing The Lawn For Over-Sowing, for more specific details on how to go about it.

Working up an area for seeding is an almost fool proof way of establishing a great lawn. It allows the lawn area to be levelled and the lawn to establish more quickly. This process does require considerably more effort but is often hugely rewarding both from an aesthetic perspective. The article, Preparing The Soil For A New Lawn is a great place to start if you are considering this.

Should I Use Ready Lawn Or Sow Seed?

The answer depends on your budget, whether you have the time to prepare and sow a lawn, and how quickly you expect a result. Ready lawn costs about $11 per square metre plus freight for a standard variety. Based on a small, 10m x 8 m lawn, that is a cost of at least $950 plus installation. The same seed for that area will cost about $45 plus preparation costs. There is still basic soil preparation required before laying ready lawn such as levelling and spraying out the old lawn. The final consideration relates to your patience. Ready lawn is instantaneous and the same result would take 12-20 weeks to be achieved through seeding.

The Plant Company recommends you read the articles, Selecting The Right Lawn Variety, Preparing The Soil For A New Lawn, and How To Seed A Lawn, as you ponder the decision about seeding or using instant lawn.

When Is The Best Time To Sow A Lawn?

Mid-spring through until mid-autumn is regarded as the best time to sow lawn seed. In warm climates seeding can occur through winter but the rate of establishment will be slower and more seedlings may be lost to diseases which tend to prevail in cold and wet conditions. Seeding in colder times can also result in more weed problems as the lawn takes longer to establish. The Plant Company recommends a minimum soil temperature of 15 degrees Celsius for Kikuyu and 10 degrees Celsius for all other varieties.

Sowing a lawn in summer is fine provided the area can be watered regularly. See The Plant Company articles on Preparing The Soil For A New Lawn and How To Seed A Lawn for great information on getting a lawn underway.