Lawn Fertiliser Buying Guide

Lawn Fertiliser Buying Guide

Choose the right fertiliser for you, your lawn, your family and your life style.

The best choice for you

Lawnsmith® lawn fertilisers are blended to give the lawn the correct amount of nutrients over a period of time. The following programmes progressively increase the fertility levels:

Basic - One Feed per Annum: If you're a busy person or reluctant gardener you can get a year’s feeding done in one go with Extra-LONG 5 to 6 month very slow release lawn feed. It will provide an essential level of nutrients to keep your lawn in good shape from Spring into Autumn

Traditional - Two Feeds per Annum: This is for hobby gardeners where a little more involvement may be desired or where use is heavy. Once again use the Extra-LONG very slow release lawn feed in spring plus an Autumn feed at the back end to maintain colour and health and promote lawn repair from the summers activities.

Flexible - Three or more Feeds per Annum: For the keen gardener or lawn enthusiast, you can exert much more control over the lawn by using 3 month slow release fertilisers and liquid fertiliser. Use the appropriate Spring & Summer feed in spring, and in summer, if conditions warrant it, either repeat the application or use Solugreen liquid feed every 4 to 6 weeks. Finish the year with an Autumn feed.

Though the nutrient levels do change between programmes, whichever way you go, any lawn feed is far better than no lawn feed!

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Common Q&A's


Is the fertiliser safe for children, dogs and cats?

Unlike grass ‘weed and feed’ products, Lawnsmith® Granular Fertilisers do not contain pesticides or weed killers. Though the bag of bulk material should be stored safely away from children and pets, the lawn may be used by children, wildlife, dogs and cats immediately after application.

If you wish to feed and kill moss at the same time then Winter Green Fertiliser is safe but can stain feet up to 72 hours after application.

If our Soluble Fertiliser or Green-up Ferrous Sulphate is used then the lawn is safe once dry. This would take just a few hours in the warmer months. Ferrous sulphate may stain feet within the first 24 hours of application.

For weed killer we suggest you use one of our liquid products as the manufacturer’s recommendations are that once dry they are safe.

A few pets have some peculiar idiosyncrasies, therefore, if you feel your pet may consume or is sensitive to these products then keep them off or don’t use the product.


Lawn products where pets graze or forage (rabbits, hens, ducks etc)

There is minimal risk if applying fertiliser in a mini granule form (all Lawnsmith® Granular Fertilisers) and therefore most pets can be allowed on the lawn immediately after application. However, those that forage down at soil level e.g. ducks and hens (and possibly rabbits and guinea pigs) are perhaps better kept off until the fertiliser has dissolved into the soil completely. This can be speeded by watering in.

With weed killer we refer you to the manufacturer’s recommendations, which may be similar to our recommendations for applying Soluble Fertiliser or Green-up Ferrous Sulphate. That is to allow 3 mowings before allowing grazing/foraging pets on the lawn. Ferrous sulphate may stain feet within the first 24 hours of application.

Finally, there are a great number of creatures under the banner 'pets' AND a large number of pets with some peculiar idiosyncrasies, therefore, if you feel your pet may consume or is sensitive to these products then keep them off or don’t use the product.


When can I apply fertiliser to the grass?

If conditions are right, which means the grass is growing and there is moisture in the soil then it is best to apply Lawnsmith® Fertilisers straight after mowing. You can also apply before or after rain.

Feeding AND Weeding

If using a weed killer concentrate on the whole lawn apply one to two weeks after applying fertiliser. If spot treating then apply when the weeds are ready.

Feeding AND Seeding

The fertiliser will help establish new grass faster so apply the feed on the same day or within a week of seeding. If over seeding do not feed before seeding otherwise your existing lawn will outgrow the new grass.

Feeding AND Moss Treatments

Feed after you've completed all moss treatment, raking and over seeding

Feeding AND Scarifying

Feed after and if over seeding then feed at the same time as seeding

Feeding AND Turfing

Apply just prior to laying


Do I need to water in the lawn feed?

Lawnsmith® Extra-LONG, Spring & Summer and Autumn fertilisers have a high safety margin and will not burn or scorch if applied when moisture is present in the surface soil. This means not having to worry about rain, weather forecasts or watering in! If the ground is dry or hard or the grass has stopped growing because it is dry then DO NOT apply.


Will the fertiliser stain my path or patio?

The only products that will cause staining on hard surfaces are Green-up Ferrous Sulphate and Winter Green Fertiliser. All of our other fertilisers are safe on hard surfaces and will not cause staining.


What is the best feed when seeding?

  1. To get the seed to germinate
  2. To get it to grow and become a lawn as quickly as possible so it can be used

Both require warmth and water but the first is down to how well you've planted your seed and the second is down to nutrition. Getting strong roots is half the battle which requires phosphate and nitrogen and getting healthy leaves requires potassium and nitrogen. Therefore adding the right fertiliser is very beneficial.

For over seeding

For existing lawns when over seeding use one of our seasonal fertilisers - the 'sandy soil' variety in spring and summer will give you a better nutrient balance even if you have clay soil. You can use 'starter' or a 'seasonal fertiliser' for patching small areas.

For new lawns

Use our Starter fertiliser. Then start feeding as a mature lawn after about 3-4 months according to one of the three programmes outlined in the Fertiliser Buying Guide.

When to apply

For convenience apply the seed and fertiliser on the same day though it is usually better to apply the fertiliser once the seed has germinated. Never feed before seeding.


When can I use liquid feed?

Fertiliser that is sprayed as a liquid is traditionally used to top up the nutrients in the lawn. A bit like you having an apple or a Kit-Kat between main meal, though some people do use liquid fertilisers as a regular monthly feed with good results.

It is not ideal as the first or last feed of the year due to its limited range of nutrients but is excellent from late spring to early autumn. Use a granular feed to start and finish the lawn year.

Finally, because liquid feeds are taken up by the leaves of the grass you are best spraying mature grasses (at least 3 months old preferably 6 months) that are in good condition i.e. plenty of soil moisture and NOT straight after scarifying.


How do I apply lawn fertiliser?

Granular products can be applied by hand (for small lawns or awkward areas) or spreader. Because Lawnsmith® granular fertilisers don't contain pesticides you can use a rotary or broadcast spreader which is faster and gives a more even distribution compared to a drop spreader.

Soluble Fertilisers can be applied by watering can (best with our Sprinkle Bar) for lawns up to 200m2 or by knapsack sprayer. A knapsack will always be quicker and easier.


What's your soil; clay, sandy, chalk or loam?

To determine an optimum programme for your lawn we need to establish soil type. This is because different soils hold and release water, air and nutrients differently. A clay soil holds nutrients better than a sandy soil therefore a sandy soil will need a slightly stronger mix of nutrients than a clay one. This also means a slightly reduced cost for clay soil fertilisers.

Chalk soils lock up nutrients due to the high pH so you need to use fertiliser with more umph which are the ones for sandy soils.

Loam soils are that in between bit. You can use whichever fertiliser you like and which ever your lawn prefers.

When selecting a fertiliser for over seeding where young grass development is more important always select the sandy soil option.

For liquid, autumn and winter feeding we stay with the more traditional nutrient mix so that your lawn will end the year with the correct nutrients it requires on an annual basis.

Testing for clay or sandy soil?

You can often tell just by looking at your soil:

If it’s light coloured possible with a hint of yellow, orange or red then it’s very likely you have a sandy soil. If it’s dark brown or grey to black it is a rich soil (often called loam) or clay based soil.

If you can’t tell then take a small sample of soil from your garden. If you think the soil in your lawn is different from the rest of the garden then use a spade to lift a small area of lawn turf and take a golf ball size bit of soil from about 2” down.

The soil needs to have some moisture in it for these tests so do these tests after some rain.

Test 1:

Squeeze the soil in the palm of your hand; if it forms a sausage shape and stays together when you open your hand its clay based soil. If it crumbles into a few pieces then a sandy base is more likely.

Test 2:

Take a pea sized bit of soil and smear it between your fingers. If it feels smooth and silky it has a clay base. If it feels finely ‘gritty’ then it has a sand base. Hopefully the results from your two tests give the same answer!


My spreader isn't in your 'Spreader Setting's' list

Because there are so many different spreaders on the market it is impossible for use to provide settings for all spreaders. Therefore you're going to have to calibrate your spreader to our fertiliser so watch the video.


What is turf hardening?

Some fertiliser elements, normally iron and potassium, actually harden the grass (sometimes called winterizing) and help protect the delicate grass membranes from the cold and occasional winter diseases. Therefore, all autumn and winter fertilisers should contain higher proportions of one or both for a reliable green winter lawn.


How long will it keep?

If kept cool dark and dry our fertilisers will keep for at least a year with minimum loss of effectiveness.