What does the gardening term "ph" means?


Joined
Oct 11, 2015
Messages
208
Reaction score
54
The gardening term "ph" means it is a measure how acidic is your soil in your garden. This is an important thing to know because plants do not like soil that are acidic.

How about you can you give any other information or explanation about this gardening term "ph" that is an important aspect in our gardening?
 
Ad

Advertisements

Joined
Jan 8, 2015
Messages
776
Reaction score
847
Location
Very West Midlands, UK
Showcase(s):
1
Country
United Kingdom
Each division on the scale (from 0 to 14) is 10 times the one before. So a pH of 1 is ten times more alkaline than pH 0. A pH of 7 is neither acidic nor alkaline so neutral.
 
Joined
Dec 1, 2015
Messages
22
Reaction score
13
Country
Australia
Hi ReadmeByAmy

The ph scale is a measure of acidity or alkalinity, it is measured between 0 and 14 with 7 being neutral.
A low ph (anything below 7) is acidic and higher ph (above 7) is increasingly alkaline.
Extremes of either are generally undesirable; most people have heard that acid burns however strong alkalines are just as damaging. The chemical sodium hydroxide is an extremely strong alkaline that will melt pretty much anything organic.

In the context of gardening it usually refers to the soil, some plants grow better in acidic soils while others prefer it slightly alkaline.
Most plants you buy will have a tag saying something like 'use lime in the soil' (lime contains calcium that will make soil alkaline/ increase the ph) but you can also Google your plants to see what they like. As you might imagine plants from swamps or tropical rain forests are used to acidic conditions while others from soils with high levels of calcium (areas of limestone, near the coast) prefer alkaline soils.

Interestingly, soil ph can affect the color of flowers, Google 'Hydrangea flower color' to see what I mean!

I hope this helps, Troy
 
Joined
Mar 28, 2015
Messages
3,917
Reaction score
3,607
Location
Southern Chester County, PA, USA
Hardiness Zone
4 to 5 best for success.
Country
United States
@ReadmeByAmy --- in your sentence in the first frame "This is an important thing to know because plants do not like soil that are acidic." That sentence is incorrect. Some plants do not like acidic soil, some plants do like acidic soil. If you live in the north and have leaves that fall the leaves on the ground in your gardens will break down and be acidic in the soil. Things like pine needles are less acidic. Lime is usually to sweeten the soil especially for veggies, makes them taste better. Its just a matter of knowing the plant. If you want a plant placed that needs less acidic environment, you can dress around the base with a alkaline product and that will help the plant ( that is if the soil is acidic).
 
Joined
Mar 28, 2015
Messages
3,917
Reaction score
3,607
Location
Southern Chester County, PA, USA
Hardiness Zone
4 to 5 best for success.
Country
United States
Interestingly, soil ph can affect the color of flowers, Google 'Hydrangea flower color' to see what I mean!
Just want this clarified, not all Hydrangeas respond to the ph change of the soil. Hydrangeas are broken down into three families, only one of the families respond to the ph change. The other two will remain what they are no matter what you do, that is just the way it is. I have thirteen varieties, most are cream colored of of the type that does not change,

Then I have some blue ones and some pink ones, the later two are in the same garden area, and both remain the same colors I planted them for year after year and I never dress the base to change them, the soil for both are the same, (interesting now that I thought about that) WOW just realized something, maybe that ph for the hydrangeas are total bunk, I actually have three that will give up a color in the same garden area, and they remain the same colors every year. One is pink changes to red, one is blue, one is lime green and changes to purple. (and I do not fuss at all with the ph.) The garden soil is the garden soil for all three the same. Interesting.
 
Joined
Oct 11, 2015
Messages
208
Reaction score
54
@ReadmeByAmy --- in your sentence in the first frame "This is an important thing to know because plants do not like soil that are acidic." That sentence is incorrect. Some plants do not like acidic soil, some plants do like acidic soil. If you live in the north and have leaves that fall the leaves on the ground in your gardens will break down and be acidic in the soil. Things like pine needles are less acidic. Lime is usually to sweeten the soil especially for veggies, makes them taste better. Its just a matter of knowing the plant. If you want a plant placed that needs less acidic environment, you can dress around the base with a alkaline product and that will help the plant ( that is if the soil is acidic).

Why that sentence is incorrect?....
 
Ad

Advertisements

Joined
Mar 24, 2015
Messages
606
Reaction score
927
Location
Close to The Garden of England
Hardiness Zone
8b
Why that sentence is incorrect?....

I think that Esther is only referring to the fact that some plants do like acid soils. :) (I'm sure that she can speak for herself - sorry, Esther. ;))

To go back to the original question. pH is generally taken to mean 'potential of hydrogen' but there's still some discussion as to what it originally stood for as it is a translation. It refers to the potential of the amount of hydrogen that can be absorbed in water. In plants this is important because it also determines the amount of water and nutrients that it can absorb into itself - very much oversimplified!

Although very important for the plants it isn't something specifically about plants. It's just a method of defining the acidity or alkalinity of any chemical structure. The scale runs from 0 - 14 but there are chemicals that can run off the scale at either end. Also, the pH can be affected (slightly) by the temperature of the water.

The colour of some plants is affected by the pH level and there are quite a lot of plants that prefer slightly acidic soils.

For general gardening the importance isn't particularly high unless you want to grow certain plants. For instance, camellias, azaleas and gardenias prefer an acid soil and will not be able to absorb their nutrients properly in a soil of pH 6.5 or higher. That is why a lot of people, in alkali soil areas, grow them in pots of ericaceous soil.

Funnily enough, there are some plants that help others. Laurel, which prefers acid soils, but is happy in almost any type, will help make the soil around it slightly more acid as the roots spread finely through the soil.

Most garden soils are in the 6.5 - 7 (and almost all are between 6.5 - 7.5) range so are fairly suitable for most plants.

Here's a good link to a list of plants and what types of soil they prefer.

http://lazycompost.com/pH.shtml

Totally non-relevant to the topic but of interest to a lot of people is the pH of hair and skin. These range from 4.5 - 5.5 so are acidic. If you use a detergent shampoo on your hair you will be doing damage to the outer layer cuticle) of the hair because detergents are alkaline. That's why you see advertisements for low pH or acid shampoos (and skin cleansing agents).

To use an analogy, the cuticle of the hair is like fish scales that lie flat on the hair to protect it. If they get raised up then chemicals can enter the hair (that's what happens when colours or perms are put on the hair as they have a high pH level) but the cuticles can then get caught into each other and your hair tangles up.

Conditioners are of a low pH level to try and get the cuticles back down again. Very much oversimplified but it gets the idea across. Try not to use strong detergent or high pH shampoos!

Whoops! That was rather long - my fingers ran away with me! :D
 
Joined
Jul 29, 2015
Messages
163
Reaction score
27
Country
Kenya
I think that the lower the pH, the greater the acidity of the soil. A well maintained soil pH will maintain the value of the soil and maximize crop production. It is recommended that we maintain soil ph at above 5.5 in the topsoil and 4.8 in the subsurface. We are not supposed to plant any crop until we measures soil ph.
 
Joined
Mar 24, 2015
Messages
606
Reaction score
927
Location
Close to The Garden of England
Hardiness Zone
8b
To try and get the ideal soil for the plants you want to grow is almost impossible unless you specialise in just a particular group. Changing the pH of your soil can be hard work and expensive.

As most plants are very tolerant it's best to just go with the pH level you already have. There's no point in worrying about the pH of your soil unless you want to grow specific plants.

Gardening is a fun past time and once you know what the pH of your soil is (if you really want to bother) you can aim at the plants that are listed in the link in my previous post.

I grow, literally, thousands of plants and don't worry about what soil they prefer. They get by just fine. (y)
 
Ad

Advertisements

Joined
Mar 24, 2015
Messages
606
Reaction score
927
Location
Close to The Garden of England
Hardiness Zone
8b
Dressing the fields with calcium carbonate (the main constituent of lime) helps reduce the acidity of the soil and improve the uptake of nutrients NPK (nitrogen, phosphorus, potash).

Most edible crops prefer a soil value in the region of 6.5 pH. So, on a large amount of farmland that is generally around 5.5 it will have the desired effect and increase yields. Winter is the correct time to dress the fields.

A lot of flowers, shrubs, trees and perennials are happier at higher levels.
 
Ad

Advertisements


Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments. After that, you can post your question and our members will help you out.

Ask a Question

Top