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4 Best Soil Testing Kits for pH Acidity, Moisture and Light (2021 Review)

In this guide we’ll take a look at the best soil pH testing kits for the UK market.
I’ve compared pH accuracy, features, ease of use and cost
to give you my top recommendations.

What is the Best Soil pH Testing Kit?

In a rush? Here's my top choice...

4-in-1 Soil Test Kit (pH, Moisture, Light, Temperature)

Incredibly accurate and informative tool!

This 4-in-1 Soil Test Kit will not only let you know about soil pH, but also the temperature, light and moisture. The easy-read digital display will clearly show the readings within seconds. It requires 1 x 9V battery (not included) and will even automatically turn off after 5 mins of inactivity to save battery life.

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Everything I Recommend

IMAGE RECOMMENDED PRODUCTSPRODUCT FEATURES
  • Digital readings
  • Fast response time
  • 5 min auto-power off
  • Capsule-based tests
  • Contains 10 tests
  • Economical
  • Tests major nutrients in soil
  • Contains 350 tests
  • Ensures a quality crop
  • Acid/alkaline indicator
  • Contains 15 tests
  • Simple to use

More Detailed Soil Testing Kit Reviews

4-in-1 Soil Test Kit (pH, Moisture, Light, Temperature)

FEATURES RATING PRICE
FEATURES
  • Digital readings
  • Fast response time
  • 5 min auto-power off
OUR RATING
93
PRICE
CHECK PRICE →

4-in-1 Soil Test Kit (pH, Moisture, Light, Temperature) Review

This 4-in-1 Soil Test Kit is really useful for anyone looking for digital accuracy out in the garden.

Able to measure not only soil pH, but moisture, light and temperature levels too, it really is an all-encompassing tool.

You can get the results in seconds after inserting the probe into the soil, all displayed on an easy-to-read digital screen.

You can put that old pH colour chart printout away – you won’t be needing it anymore!

It will let you know when it’s running low on battery power, and requires 1 x 9V battery (not included).

Overall this is an incredible tool for letting you know the exact conditions of the soil and the surroundings. You’ll have everything you need at your fingertips to create the best climate for maintaining healthy plants!

Luster Leaf pH Soil Tester

FEATURES RATING PRICE
FEATURES
  • Capsule-based tests
  • Contains 10 tests
  • Economical
OUR RATING
92
PRICE
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Luster Leaf pH Soil Tester Review

This Luster Leaf pH Soil Tester is probably the quickest, easiest, and cheapest soil test kit on the market.

If you’re purely interested in the pH, and not fussed about moisture, light or temperature readings too, this simple kit is the way to go.

It comes with a handy colour chart to measure your readings. Although this doesn’t have the accuracy of pricier models, it’s perfectly fine for your weekend gardening when you just need to know which plant to bed where.

When it comes to value for money and simplicity, it’s the best soil pH testing kit around.

Professional Soil Testing Kit

FEATURES RATING PRICE
FEATURES
  • Tests major nutrients in soil
  • Contains 350 tests
  • Ensures a quality crop
OUR RATING
89
PRICE
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Professional Soil Testing Kit Review

If your soil testing needs go beyond a few simple readings, and perhaps the quality of your crop is linked to your commercial success, this professional soil testing kit is certainly worth your consideration.

Not only can this Professional Soil Testing Kit test for pH, but it also goes as far as testing for important nutrients in your soil such as nitrogen, phosphorus and potash.

All of these play a crucial role in promoting the health of your yield.

Capable of performing 350 tests, but compact enough to fit inside a tidy carry-case, this soil testing kit is suitable for those after a more scientific insight into their soil composition.

Gardener’s Mate Soil pH Testing Kit

FEATURES RATING PRICE
FEATURES
  • Acid/alkaline indicator
  • Contains 15 tests
  • Simple to use
OUR RATING
85
PRICE
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Gardener’s Mate Soil pH Testing Kit Review

The Gardener’s Mate Soil Testing Kit is another good option for your those looking for basic insight on their soil.

Although it doesn’t have all the fancy features of other kits on my list, it’s a perfectly good indicator for those who just want to know whether their soil is acid or alkaline.

The kit contains 15 tests and is straightforward to use. It may not be as accurate as some of the digital readers, but if you just want some basic information to inform your planting decisions this will certainly do the job.

Readings are taken by comparing results against a handy colour chart; however, it’ll take a little longer to get results than with some of the other kits.

Things to Know Before Buying a Soil Testing Kit

Testing the pH of your soil is the best way to know if your plants are living in their optimum conditions.

The pH levels dictate what sorts of nutrients are available in the soil; therefore, some plants may prosper in acidic (pH 1 – 6) ground, whilst others need neutral or alkaline conditions (pH 7 – 14).

One thing’s for certain – using a soil testing kit will give you a more accurate idea of what you should plant, as well as how to better care for the plants you already have. The following information will help you better understand soil conditions and how to find the best soil testing kit:

Soil pH describes the acidic or alkaline nature of your soil. This indicates what kind of nutrients your soil is likely to hold. Nutrients like iron, magnesium, calcium and potassium are important for healthy plant growth. These are more present in certain types of soil than others, and some plants prefer more or less of each nutrient.

A pH of 7 means your soil is neutral. At this point soil nutrients are at their most balanced. Anything above pH 7 is alkaline (think chalky) anything lower than 7 is acidic.

Alkaline Soil

A pH above 7 means the soil is alkaline. At this point phosphorous, iron and manganese levels are lowered. This can lead to poor plant growth, but on the plus side it reduces club-root disease in brassicas (greenery such as cabbage). There’s always a bright side!

Alkaline is the most difficult type of soil to change, so you’re best off choosing plants that like alkaline soil.

If you desperately want to the change your alkaline soil conditions then you’re in for a struggle with Mother Nature. Use acidifying sulphur agents or buy pine needle compost. Keep digging it in and mulch thickly with ‘organic matter’ (that’s horse/ chicken /farmyard poo to most of us). You’ll need to make these improvements every year because the soil will revert back to its comfort zone.

Acidic Soil

A pH below 7 points to acid soil. That sounds bad but it’s actually beneficial in small amounts. It depends how acidic it is.

A pH of 3 – 5 is very acidic. There’s going to be a lack of copper, calcium and magnesium. Bacteria is unable to break down plants and organic matter when the pH is below 4.7, meaning no goodness gets into the soil. Nutrients are used up quickly with no replenishment.

Or perhaps you’ve got an acid pH of 5 – 6. That’s not so bad. You’ll be a master of rhododendrons who love acidic conditions. You’ll still have some of the issues above but not to such an extent.

A pH of 6 – 7 is the least acidic and good for growing. Just about everything will thrive in this soil because the nutrients are plentiful. It’s Club Tropicana for worms.

If your soil is very acidic you can dig in lime. This will help balance out your pH, but you’ll have to keep doing it each year.

Neutral Soil

A pH of 7.0 is considered neutral. Plant whatever you like.

This topic is going to cause some debate…

An overly acidic or alkaline soil pH can mean your garden doesn’t have enough of the nutrients your plants require. Is this a problem? It depends on your gardening personality.

There are two main types of gardener as I see it:

Type 1 – tests the soil, improves it if necessary and chooses plants based on their scientific data. Manure is delivered on a tail-gated lorry each year. They grow rather enormous carrots and blue hydrangeas. When asked what type of soil they have reply with ‘Mildly alkaline but nearing neutral in some borders.’

Type 2 – buy plants they love, and hope for the best. They follow the ethos that plants have managed for thousands of years without interference so it’s worth taking a chance. They like daisies in the lawn. When asked what type of soil they have reply with ‘brown’, ‘clay-y’, or ‘dry’.

Obviously soil pH is going to matter more to a type 1 gardener than a type 2.

If you’ve been having problems in your garden, unable to grow the types of plants that you’re longing for, it’s a good time to get a soil testing kit and find out what’s going on in the dirt. It’s possible that this simple test will suddenly reveal all of the answers about why certain plants are thriving and others aren’t!

You’ve got a few options to help identify the pH of you soil:

Use a Soil Testing Kit

The most straight forward option in my opinion: buy a soil testing kit. These are simple to use, with a range of prices and ‘sophistication’ levels to suit all budgets and expectations.

If you only want to know about the pH, you can buy tests solely for this purpose – they might be ‘one use’, but you normally get at least 10 in a pack. As a result, you can test several areas in the garden.

Otherwise, you can buy a digital tester which will allow you to check data about your soil to you heart’s content. These readers will often not only check pH levels, but moisture, light and temperature as well.

Use a Professional Service

Alternatively, you can send a sample of soil off to places such as the RHS for scientific analysis.

This will give you a very accurate reading, but you might have to wait a long time to find out the results. Plus, you’ll have to send off several different samples if you’re hoping to test various areas in your garden.

Ultimately, this can add up to be quite a costly process – it is around £30 to have one sample analysed.

Take a Peek at Your Neighbour’s Garden

Not a particularly scientific method, but a fairly harmless place to start getting an idea about the soil pH in your area.

Perhaps the cheapest way to identify your soil pH is by taking a look in your neighbour’s garden. If they have marvellous camellias and rhododendrons in the ground, the soil is acidic. Stunning clematis, cherry and yew mean it’s likely to be alkaline.

DIY Soil Testing

If you want to take matters into your own hands, you could give these two DIY methods a go:

The Vinegar and Baking Soda Method

You’ll need:

  • Soil
  • Baking soda
  • Vinegar
  1. Scoop up a good handful of soil from the growing areas of your garden. Separate this into two cups. Add vinegar to one cup of soil. If it fizzes it’s alkaline.
  2. Add some water to your other cup of soil so it’s tacky and muddy but not drowned. Add half a cup of baking soda. If it fizzes, your soil is acidic.

No reaction means you’ve got a pH of 6.5 -7, the most versatile type of soil.

The Hydrangea Method:

You’ll need:

  • A mophead or lacecap hydrangea, but not a white one.

Hydrangeas act almost as a unique form of litmus paper.

Most varieties of hydrangea will bloom blue in acidic soil and bloom pink in alkaline. A white variety will stay white (which is why it’s no good using one of these for this test)!

If you desperately want the blue type, grow your hydrangea in ericaceous compost. This is easily found online or in garden centres. You should also water it with rain water because hard tap water can turn blue flowers pink!

blue-hydrangea

As previously mentioned, a soil testing kit is probably the most straight forward way to discover the conditions of the soil in your garden.

They offer a cheap, easy and quick way to find out what pH you’re working with.

Digital Testing Kits

If you get a digital testing kit, you’ll get a unit which has a digital display attached to a probe. The probe is inserted into the soil and gives a reading of the pH level.

A lot of the time these digital testing kits will do more than just test the pH, and this is where they really come into their own. They’ll also reveal information about the moisture, temperature and light availability. This can really help give a well-rounded view of the growing conditions for your plants.

Digital kits only require a battery to run, and this battery will last a really long time. So after the initial investment, these units can definitely save you money over time.

Chemical Testing Kits

Other testing kits tend to work in one of two ways:

Either, you mix a small amount of soil in with a solution that will change colour depending on the acidity or alkaline present. You then compare this colour with the provided colour chart and ascertain where your soil falls on the scale.

Alternatively, some kits will come with litmus paper. Again, you mix a solution with the soil, then insert a piece of litmus paper into the liquid. The litmus paper will change colour, and you will compare this colour against the colour chart provided.

These kits are good if you’re only interested in knowing the pH of your soil. They may not always be as accurate as a digital test as you are required to interpret the pH yourself by analysing the colour. You do often get several tests in a kit, so you have the opportunity to test many parts of the garden.

If your soil is neutral, mildly acidic or mildly alkaline, it isn’t going to dramatically affect your planting strategy. However, if your soil is leaning very strongly to one end of the pH scale, you’ll save money and time buying plants that suit it.

If you have a strong pH, sometimes you can still grow ‘unsuitable’ plants. You can do this by filling the planting hole with compost and mulching regularly. This maintains a more neutral growing condition. I do this with camellias on my alkaline soil and they’re doing just fine.

If you’d rather not fight nature, here’s a rundown of some easy-to-grow plants, depending on the pH of your soil:

Acidic Soil

Beans, blueberries, magnolias, Japanese anemone, rhododendron, summer heather, pieris, camellia, acers, azaleas, berberis and begonia.

rhododendron-1024x350

Alkaline Soil

Alpine pinks, delphiniums, baby’s breath, carnations, ferns, lilacs, mock orange and spiraea.

mock-orange-1024x682

If you have an acid-loving plant, listed above, that has yellowing leaves and stunted growth, you probably have alkaline soil. Dig the plant out and house it in a container of compost. If they improve, then you know soil pH is the problem.

You can’t go wrong by digging manure or compost into your soil, no matter the pH. Organic matter replenishes spent soil. You can’t expect nutrients to last forever, especially the way we rake up leaves and remove all the food plants have made for themselves.

Try digging your leaf fall into the earth, if you don’t have leaf fall, invest in some compost and you’ll see you plants improve no matter if it’s acidic or alkaline soil they’re in.

To Make Soil More Acidic

  • You can use fertilizer to make soil more acidic. Look for a fertilizer which mentions increasing acidity; these fertilizers often contain ammonium nitrate or ammonium sulfate.
  • Adding ‘sphagnum peat’ in the garden will also increase the acidity of the soil. You can add up to 5 cm of this peat around plants when planting.
  • If you want to increase the acid levels in potted plants, you can even water them with a solution of water and vinegar. Mix 1/2 – 2 tbsp. of water with 4.5 L of water. Be careful not to make the solution too strong, and keep it away from the leaves of the plant as it can easily burn them.

To Make Soil More Alkaline

  • Adding lime to soil is most commonly used to increase the soil pH and make it more alklaline.

It’s worth being aware of your soil pH because it can help your plants to thrive. You only need to do this once and then simply choose suitable plants. This will cut down on work, save you money, brighten your outside space and make all the difference to your garden.

Soil Testing Kit FAQs

Yes. As long as you make sure to buy a quality kit, even home testing kits have been shown to be between 92 – 94% accurate.

Doing a home soil pH test is definitely the easiest way to find out the pH of your soil.

There are some other options available to you as well:

  • Use a professional service
  • Identify if you or your neighbours are successfully growing blue hydrangeas (the soil will be acidic in this case). Or pink hydrangeas (this will mean the soil is alkaline).
  • Use vinegar and baking soda. Take a handful of soil from your garden. Separate this into two cups. Add vinegar to one cup. If it fizzes, the soil is is alkaline. Add some water to your other cup of soil. Add half a cup of baking soda. If it fizzes, your soil is acidic.

Numbers from 1 – 6 are acidic. 1 is the most acidic, and 6 is on the acidic side of neutral. The colours range from a dark red at the most acidic pH 1 end, to yellow at pH 6.

pH 7 is neutral. pH 7 is represented by a light green.

pH 8 – 14 are alkaline, with pH 14 being the most alkaline. pH 8, 9 and 10 are green (getting progressively darker), pH 11 is light blue and pH 12 dark blue. pH 13 is indigo, and 14 is violet.

Sources
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