Acid-Base soil question

Hi, you can get kits to test the ph [acidity/alkalinity] of the soil from normal plant nurseries.

"When to test soil pH


It is especially worth checking soil pH before designing or planting a new garden, making vegetable plots, planting fruit, when growth is disappointing, or where yellowing of foliage occurs.

Lime is added to increase soil pH (make it more alkaline) and acidifying materials are added to decrease soil pH.

Testing can be done at any time, but if carried out within three months of adding lime, fertiliser or organic matter, the test may give misleading results.



How to test soil pH


Professional testing: RHS soil analysis service provides a full written report.

Home testing: You can test your soil pH yourself using a DIY kit widely available at garden centres. These kits are relatively cheap and easy to use and give a good indication of soil pH. But for the best results, send a soil sample to a laboratory for detailed analysis.

Always follow the sampling directions given by the test kit or laboratory to get a representative sample for the area in question.

Laboratory tests also detect free calcium carbonate (chalk or limestone). This may not be measured by DIY kits. A quick home test to check for free calcium carbonate is to add vinegar to a soil sample. If ‘fizzing’ is seen, free calcium carbonate is present.

Interpreting the results of a soil pH test
A pH test measures soil acidity or alkalinity. A pH 7.0 is considered neutral. An acid soil has a pH value below 7.0. Above pH 7.0 the soil is alkaline.

pH 3.0 - 5.0

• Very acid soil
• Most plant nutrients, particularly calcium, potassium, magnesium and copper, become more soluble under very acid conditions and are easily washed away
• Most phosphates are locked up and unavailable to plants below pH 5.1, although some acid tolerant plants can utilise aluminium phosphate
• Acid sandy soils are often deficient in trace elements
• Bacteria cannot rot organic matter below pH 4.7 resulting in fewer nutrients being available to plants
• Action: Add lime to raise the pH to above 5.0. The addition of lime can help break up acidclay soils

pH 5.1 - 6.0

• Acid soil
• Ideal for ericaceous (lime-hating) plants such as rhododendrons, camellias and heathers
• Action: Add lime if other plants are grown

pH 6.1 - 7.0

• Moderately acid soil
• A pH 6.5 is the best general purpose pH for gardens, allowing a wide range of plants to grow, except lime-hating plants
• The availability of major nutrients is at its highest and bacterial and earthworm activity is optimum at this pH
• Action: It is not usually necessary to add anything to improve soil pH at this level

pH 7.1 - 8.0

• Alkaline soil
• Phosphorus availability decreases
• Iron and manganese become less available leading to lime-induced chlorosis
• But an advantage of this pH level is that clubroot disease of cabbage family crops (brassicas) is reduced
• Action: Sulphur, iron sulphate and other acidifying agents can sometimes be added to reduce pH. Clay soils often require very large amounts of acidifying material and soils with free chalk or lime are not usually treatable

Problems


Certain plant diseases such as club root and nutrient deficiencies can be associated with acid or alkaline soil conditions."


You can normally tell generally what ph your soil is by looking around at your neighbours garden and if there are Rhododendrons, Azealias, Camellias, Heathers being grown in them then you've more likely than not to have acid soil.......which is suitable for Blackberries

 

pH testing kits are cheap and easily found in garden centres (I doubt that nurseries would stock them, make sure you ring before making a special trip), something like this will do the job:



http://www.amazon.co.uk/Two-Wests-Elliott-257-Testing/dp/B0017866I4

(PS: I've personally not tried that particular kit but I have used a very similar one).

Don't get one of these very cheap pH meters that has probes you stick in the soil as they are totally useless:

 

If you want to use a lab to get all the nutrient readings as well then I'd recommend the RHS soil analysis service for £25 for members (£30 for non-members):
https://www.rhs.org.uk/membership/rhs-gardening-advice/soil-analysis

 

Pete's right about that Chemical kits are cheap and easy to use, and I did buy my last one at a Plant Nursery.

Advice from the RHS on Blackberries

Growing
Top-dress blackberries with 100g per sq m (4oz per sq yard) of general-purpose fertiliser in mid-spring and cover with a 7cm (3in) organic mulch annually. Make sure the mulch is placed 5cm (2in) away from the new canes and the crown to prevent rotting.

Water young plants every 7-10 days during dry spells. While mature plants shouldn’t need extra watering, their fruit size will benefit from watering every 10-14 days if the summer is particularly dry.

Pruning and training
Blackberries are vigorous and need regular pruning and training. Regularly tie in the shoots of newly-planted canes. Once these reach their first winter, cut back all sideshoots produced on these main canes to 5cm (2in). It is mainly from the resulting fruiting spurs that flowers are formed.

In the second year after planting the crown will throw up new canes from ground level. Loosely bundle these together; insert four bamboo canes in a square vertically around the crown and pull the new canes into the centre; then tie some sturdy twine around the square to hold the new canes in place.

Remove the one-year-old canes once they have fruited by pruning them into shorter sections with loppers, then extracting them carefully to prevent their thorns snagging on new canes. Then untie the twine around the new canes and train them along the wires.




Leafhoppers: The jumping, light green insects, roughly 3mm (1⁄8in) long, may occur on plants in sheltered sites, causing white flecking on the leaves.

Remedy: Control measures are not necessary.

More info on Leafhoppers

Blackberry cane spot: This can cause grey spotting on affected canes, which sometimes spreads to foliage. As spots enlarge, canes may split and eventually die.

 

Yes definitely worth trying your meter now you've bought it - hopefully you can prove me wrong Please let me know how it's results compares with the kit and the university soil test

 

Ah this is the explanation then, as Blackberries fruit on the previous year's growth. Autumn pruning regime is: leave the new canes that have grown over the summer whilst removing the current years canes that have already fruited. Not quite so easy to do now as it's not immediately obviously which are old and which are new canes, they are a different colour; the new ones will look greener and fresher whilst the old ones are greyer and brittle. As you cut them all down a year ago then they should all be new canes waiting to give you a bumper harvest this year!

 

If the plants are very vigorous growers you can also lightly prune the new growth when you cut back the old growth.

From looking at your berries there can be a number of reasons for poor growth. There could be some disease that has affected them but there's little you can do about that. The usual reason is that it's due to one of the many insects that can affect them and cause the flowers not to pollinate properly.

This is always a matter of the balance of wildlife. You need the beneficial insects to pollinate the plants so you can't be too harsh with trying to keep the nasty ones away. You will need to keep an eye on the underside of the leaves to see what insects like your plants.

I don't know what type of insects are prevalent in your part of the world but I guess, from your wording, that you are on the other side of the pond! Sorry if I'm wrong.

Blackberries are, in general, quite tolerant of conditions but are happier in a neutral or slightly acidic soil. A light feed each Spring helps.

Having said all that. We treat our plants quite harshly and don't feed them, but they have been here for 60 years and their roots are extremely well established. Each Autumn/Winter we cut out the old wood and prune the new down to about 2ft. The plants are very vigorous and can grow 30ft in a season. Any branches that are growing too long also get pruned in late Spring/early Summer and they then produce more fruiting side shoots.

 

Now you have me puzzled!

You say you have put your soil through that process before taking it to the lab for analysis . How are they going to know what the pH of your soil is now that you've soaked it in an alkaline solution with a pH of at least 12?