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Which Fertiliser Should I Use?


Liquid fertiliser from a watering can - Boston Seeds 

Your lawn is the only plant in your garden that is cut down over twenty times per year. If you collected all the grass clippings over a season, you’d see just how much plant material is removed! These leaves that we clip without thinking are the result of the plant photosynthesising and removing nutrients from the soil. 

Your lawn is also the only plant in your garden that is walked on, played on and generally subjected to a lot of abuse. Using the right fertiliser at the right time can help replace the lost nutrients, keep weeds and moss at bay and help your lawn recover.

Which fertiliser is best for all plants?

The best fertiliser for lawns and plants will change throughout the year. It’s important to make fertilising part of a seasonal process as ratios of each nutrient required change seasonally. You’ll also find additional benefits in many of Boston Seeds fertilisers with weed killer and moss destroying properties.

Whatever fertiliser you do choose, we recommend using a seed spreader to ensure even coverage. 

Best fertiliser for early spring

When choosing spring lawn feed, choose a fertiliser with high nitrogen levels as it encourages new growth.

BS Spring & Summer Lawn Fertiliser has a higher nitrogen content which encourages leaf and shoot growth, making it the perfect spring lawn feed. It’s best used from March-September and will steadily release nutrients over a 6-8 week period.

Best fertiliser for grass in summer

A spring-summer lawn fertiliser mix like the BS Premium Spring & Summer Lawn Fertiliser offers the perfect extra boost in hotter months. Containing NPK at a ratio of 12.5.5, along with 1% MgO, 2% Fe and Seaweed, it’s a premium fertiliser for lawn and turf areas that will keep it looking luscious and green. 

Best fertiliser for grass in autumn and winter

At the end of each growing season, we recommend using BS Autumn & Winter Lawn Fertiliser, which has been specially formulated to provide nutrients throughout this period. The addition of iron and magnesium helps protect against turf diseases and gives the grass a rich green colour.

For year-round granular lawn fertiliser coverage, the BS Year Round Lawn Fertiliser Package is a great choice. This bulk grass fertiliser package includes enough of each type of fertiliser to provide enough applications throughout the year. It’s a popular choice for amateur and professional gardeners alike.

Best slow-release fertiliser

Slow-release formulas are the best lawn fertiliser choice for low-maintenance gardening.  One of the risks when applying fertiliser is “fertiliser burn” which can result in leaves and plants withering and browning. In lawns, the most common symptoms are streaks of yellow, brown or white grass.

This is why many prefer to use a slow-release fertiliser, like BS Slow Release Lawn Fertiliser, which releases nutrients over a period of six months. It minimises the chance of over fertilising your lawn and you don’t have to worry about forgetting to top it up every few weeks.

Best fertiliser for new grass seed

When you’re sowing new grass seed, you want to make sure that your grass has everything it needs. That’s why we recommend using a fertiliser before sowing lawn seeds to help encourage even growth leading to a quicker, denser coverage.

The BS Pre-Seeding Lawn and Sportsfield Fertiliser has been specifically formulated to improve the establishment of grass seed quickly and create the ultimate luscious grass. 

Best fertiliser for horse paddocks

It’s important to find the right equine fertiliser for your paddock because it’s an essential grazing source for your hoses. Our KissMyGrass horse paddock fertiliser range is developed with a free-flowing formulation for accurate application of balanced nutrients. 

Our Maintainer Paddock Fertiliser actively encourages regrowth so it can continue to be a valuable spot for grazing throughout the year. For non-ryegrass swards, we also offer Sustain Paddock Fertiliser, which is suitable for autumnal applications.

Best pet-friendly lawn fertiliser

If you have animals, it’s important to consider pet friendly lawn care. If you find any clumps of fertiliser, make sure you break them up with a tool like a trowel. If left unbroken, it may look like something unusual that they want to explore and possibly eat! Using a seed spreader should stop any fertiliser clumps but make sure to double check your lawn after application.

You can also look at the ingredients, seaweed based fertiliser for lawns are generally pet safe. If you’re not sure which product is best get in touch with us and we’ll be happy to help.

How long after fertilising a lawn is it safe for pets?

You’ll find specific safety advice on your fertiliser bag but a general rule would be to keep animals off your lawn for at least 24 hours. This gives the fertiliser time to absorb into the ground fully. You should closely follow the instructions specific to your fertiliser though. 

Best moss killer for lawns

While moss looks wonderful in woodlands, it isn’t a welcome lawn addition. Moss on lawns is damaging because, like weeds, they steal precious nutrients from your grass.

Moss is generally a sign of an underlying problem with your lawn, such as poor drainage or overly acidic soil. The right fertiliser can dramatically improve the health of your lawn, keep moss at bay and leave your lawn looking verdant.

When deciding when to apply moss killer, it’s best to do it as soon as possible. For mild problems we recommend the all inclusive BS Lawn Feed and Weed Plus Moss Killer. It will provide nutrients over 6-8 weeks and leave your grass with a beautiful dark green finish and no moss in sight. If your moss problem is already more severe, the BS Lawn Revivor and Moss Destroyer is a very fast acting fertiliser and our most powerful moss control product.

Which is better, liquid or granular lawn fertiliser?

Granular fertilisers release nutrients over a period of time, generally 6-8 weeks, to ensure a slow and steady supply of nutrients. Liquid fertiliser is much quicker, often working in only 2-4 weeks. 

Granular fertiliser can either be applied by hand or with a lawn fertiliser spreader for a quicker, more even finish. Liquid fertiliser is mostly mixed with water and applied with a watering can or sprayer, which can make it difficult to evenly apply over large areas.

In general, we recommend granular fertilisers as they feed the plant directly at the root whereas liquid fertilisers rely on the plant absorbing nutrients through the leaves. This means liquid fertilisers are not useful for preparing soil pre-seeding or for new shoots which don’t have full leaves yet.

What do fertilisers contain?

There are three primary nutrients in the majority of fertilisers

Nitrogen (N) Plants cannot absorb nitrogen from the air, so this nutrient must be absorbed from the soil. It forms part of the chlorophyll, the green colour, and so it is essential for photosynthesis.

Phosphorous (P) This assists in grass growth and encourages rooting, but excessive use can lead to a build-up of thatch.

Potassium (K) This controls the stomata and therefore water loss within the plant and can affect the drought tolerance of your lawn.

Secondary nutrients are in less demand and are rarely included in lawn feed due to the cost, however, they are still essential for a healthy lawn. Magnesium (Mg) is associated with photosynthesis and chlorophyll, and seaweed (containing iron, boron and zinc) provides the trace elements missing from soil.


Have a question about choosing the right fertiliser for your lawn? Get in touch either by email, phone or contact form and one of our experts will help you figure which fertiliser is the one for you.