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best-slow-release-fertilizer

The UK's bestSlow Release Fertilisers2022 Review

Updated: March 21, 2022

Written by:

In this guide we’ll take a look at the best slow release fertilisers.
We’ve compared ingredients, ease of application, results and cost
to give you our top recommendations.

What is the Best Slow Release Fertiliser?

IMAGE RECOMMENDED PRODUCTSPRODUCT FEATURES
best-slow-release-fertilisers Jobe’s Houseplant Food Spikes Fertiliser
Top Pick
Jobe’s Houseplant Food Spikes Fertiliser
  • Best fertiliser for houseplants
  • Very easy to use
  • Great value for money
best-slow-release-fertilisers Incredibloom Plant Fertiliser Controlled Slow Release
Incredibloom Plant Fertiliser Controlled Slow Release
  • Best fertiliser for flowers
  • Released over 7 months
  • Double nitrogen content
best-slow-release-fertilisers Osmocote 50 Slow Release Fertiliser
Osmocote 50 Slow Release Fertiliser
  • Best for hanging plants
  • Release nutrients over 5-6 months
  • No waste
best-slow-release-fertilisers Thompson & Morgan Slow Release Fertiliser
Thompson & Morgan Slow Release Fertiliser
  • Best fertiliser for veggies
  • Double nitrogen technology
  • 400% more blooms
best-slow-release-fertilisers URPril™ Slow Release Nitrogen Fertiliser
URPril™ Slow Release Nitrogen Fertiliser
  • Best slow release fertiliser
  • 46% nitrogen content
  • Wide coverage

More Detailed Slow Release Fertiliser Reviews

B00YZ9SJ32
0073035250016
Best fertiliser for houseplants, Very easy to use, Great value for money,

Jobe’s Houseplant Food Spikes Fertiliser

best-slow-release-fertilisers Jobe’s Houseplant Food Spikes Fertiliser
FEATURES RATING PRICE
FEATURES
  • Best fertiliser for houseplants
  • Very easy to use
  • Great value for money
RATING
98
PRICE
Save 25% on Amazon

Jobe’s Houseplant Food Spikes Fertiliser Review

The Jobe’s Houseplant Food Spikes Fertiliser is the best organic slow release fertiliser and fantastic value for money. Suitable for indoor use, this fertiliser contains all the nutrients your precious houseplants need to thrive.

With the perfect balance of nitrogen, phosphorus and potassium, at 13-4-5, this fertiliser will have your house plants looking beautiful in no time at all. It’s exceptionally easy to use, simply insert the food spikes into the soil around your plant. The spikes will provide a continuous supply of nutrients down to the roots.

If you’re looking for the best slow release fertiliser for houseplants, the Jobe’s Houseplant Food Spikes are the ones for you!

Save 25% on Amazon
B0158IVK6Q
5055550478460
Best fertiliser for flowers, Released over 7 months, Double nitrogen content,

Incredibloom Plant Fertiliser Controlled Slow Release

best-slow-release-fertilisers Incredibloom Plant Fertiliser Controlled Slow Release
FEATURES RATING PRICE
FEATURES
  • Best fertiliser for flowers
  • Released over 7 months
  • Double nitrogen content
RATING
95
PRICE
Check Price on Amazon

Incredibloom Plant Fertiliser Controlled Slow Release Review

The Incredibloom Plant Fertiliser is the best slow release fertiliser for flowers, allowing you to grow up to 4 times more flowers than you would without. Enjoy healthy and vigorous green foliage that’ll make your garden the envy of your neighbours!

This fertiliser is easy to use, producing results in just a single application. The fertiliser is released over 7 months, with the unique double nitrogen technology helping your flowers to thrive. It has the perfect NPK balance of 14-5-19.

If you’re looking for the best value slow release fertiliser for flowers, you can’t go wrong with the Incredibloom Plant Fertiliser.

Check Price on Amazon
B07G9F3HHC
Best for hanging plants, Release nutrients over 5-6 months, No waste,

Osmocote 50 Slow Release Fertiliser

best-slow-release-fertilisers Osmocote 50 Slow Release Fertiliser
FEATURES RATING PRICE
FEATURES
  • Best for hanging plants
  • Release nutrients over 5-6 months
  • No waste
RATING
93
PRICE
Check Price on Amazon

Osmocote 50 Slow Release Fertiliser Review

The Osmocote 50 Slow Release Fertiliser is the best slow release fertiliser for hanging plant baskets. This fertiliser is sold in individual tablets which makes it great value for money and ensures there’s no waste.

These tablets work straight down to the roots and contain a range of ingredients that your plants will love. They release essential nutrients slowly over 5-6 months to help your hanging plants thrive.

If you’re looking for the best slow release fertiliser for hanging plant baskets, the Osmocote 50 Slow Release Fertiliser is our top recommendation.

Check Price on Amazon
B07BBRWTND
5057554006755
Best fertiliser for veggies, Double nitrogen technology, 400% more blooms,

Thompson & Morgan Slow Release Fertiliser

best-slow-release-fertilisers Thompson & Morgan Slow Release Fertiliser
FEATURES RATING PRICE
FEATURES
  • Best fertiliser for veggies
  • Double nitrogen technology
  • 400% more blooms
RATING
91
PRICE
Check Price on Amazon

Thompson & Morgan Slow Release Fertiliser Review

The Thompson & Morgan Slow Release Fertiliser is the best slow release fertiliser for vegetables. This multi purpose fertiliser will give you up to 400% more blooms and up to 400% more fruit and veggies!

Containing the perfect balance of plant nutrients for crop health, this fertiliser will boost all edible crops for the entire season with just one application. It comes in a 750g tub with unique double nitrogen technology to get your fruit and veggies feeling tip top. The nutrients are released over 3 months.

If you’re looking for the best slow release fertiliser for fruit and veggies, the Thompson & Morgan Slow Release Fertiliser is our top recommendation!

Check Price on Amazon
B079QCWJH8
Best slow release fertiliser, 46% nitrogen content, Wide coverage,

URPril™ Slow Release Nitrogen Fertiliser

best-slow-release-fertilisers URPril™ Slow Release Nitrogen Fertiliser
FEATURES RATING PRICE
FEATURES
  • Best slow release fertiliser
  • 46% nitrogen content
  • Wide coverage
RATING
88
PRICE
Check Price on Amazon

URPril™ Slow Release Nitrogen Fertiliser Review

The URPril Slow Release Nitrogen Fertiliser is the best slow release fertiliser for lawns on the market. This fertiliser is very versatile, soluble in water and suitable for use as an agricultural, forestry and general grass fertiliser.

This fertiliser has a wide coverage, with 1kg fertilising an area of 200sqm. It can be applied as either a solid top dressing or a solution, and it’s made up of 46% nitrogen. It’ll give your garden the boost it needs.

If you’re looking for the best slow release lawn fertiliser on the market, the URPril Slow Release Nitrogen Fertiliser is our top recommendation!

Check Price on Amazon

How to Choose the Best Slow Release Fertiliser

A slow release fertiliser is a great purchase if you want to give your plants an extra boost of nutrients. This is especially important if you’re growing produce to eat or you pride yourself on your brightly coloured flowers. Fertiliser will give your plants a helping hand.

Slow release fertiliser is the easiest to use, helping to nourish your plants over the course of a few months. Not sure what to look for when it comes to the best slow-release fertiliser? Check out this buyer’s guide.

Ingredients

The important thing to look at in your fertiliser are the N/P/K numbers. These refer to the amount of nitrogen, phosphate and potassium present. Spring fertilisers contain more nitrogen to encourage growth, while winter fertilisers have higher levels of phosphate and potassium.

Ease of Application

Slow-release fertilisers tend to be the easiest to apply as they normally only need one application and this should see your plants through a few months. Spikes or tablets are the easiest, as these can simply be placed in the soil surrounding your plant and left to do their job.

Results

Although slow-release fertilisers release their nutrients slowly, you should see results relatively quickly. Providing you use the right fertiliser for the season, your plants should be looking and feeling healthier within a few weeks. If you’re after immediate results, you’ll need to look for fast-acting fertiliser.

Slow Release Fertiliser FAQs

What is a slow-release fertiliser and how does it work?

Slow-release fertilisers need just one application and will feed your plants for a few months. The fertiliser enters the soil and is slowly broken down, with the nutrients absorbed by the plant. The nutrients aren’t immediately available, but your plant will enjoy the perfect balance of nutrients from spring until autumn.

How to use slow-release fertiliser?

The best time to use slow-release fertiliser is in the spring when the soil is warmer. This will help your plants to thrive in the summer months.

Slow-release fertilisers come in a range of types, but they are most commonly in granular form. These can be applied dry by hand, then mixed and watered into the soil. Follow the manufacturer’s instructions when it comes to the amount of fertiliser to use on each area. Put on gloves before you touch the fertiliser.

If your fertiliser is soluble, dissolve it in the correct amount of water then apply using a watering can. For larger lawns, a knapsack sprayer will be more comfortable.

Drip feed or spike fertilisers can simply be inserted into the soil surrounding your plants.

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About Your Guide

  • Clive Harris

    Clive Harris is the creator of DIY Garden and a professional landscape gardening consultant with over 6 years experience. In his spare time he enjoys testing the latest gardening equipment and sharing his experiences here on the site. And of course, he absolutely loves his garden and spends many happy hours outside each week growing, mowing, and having fun with his three kids.
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