Saturday, April 16, 2011

Soil testing, ideal vegetable pH levels and veg patch pH adjustment

As I may have mentioned before, the kitchen garden I set up is in a challenging environment, and soil acidity - particularly near pine trees in waterlogged soil, is a worry.

The first thing to do is a Ph test of the soil.
As most readers know, 95% of the time I will always advise to buy in local Irish outlets, but I got a great deal on ebay for the kit I got.
Preston Bisset Nursaries in England do a great deal on a kit I got via their ebay shop, but you can also order them direct - tell Jacqueline and Peter I sent you.
A Westminster test kit will give you approx. 30 tests - more than enough for 2-3 years for me.
It only cost £5.95 + £2.25 postage.
That is a real bargain, its very easy and simple to use, giving accurate results.
I looked at electronic soil testers, but for the affordable ones the reviews were poor, so it is this kit I would recommend.

Alteration of soil pH should ideally be done about a month prior to planting.

To lower your soil pH, then you will need to add agricultural sulphur.
To increase your soil pH, then you will need to add agricultural lime.

Lime and sulphur are available at garden centres and packs will have directions for use.

Another idea I will be testing this year is ashes. I tested some old ash from a turf and wood stove, and found it to be very alkeli, so that will be used as a soil adjuster as well as providing bulk to try and raise a few beds.

It's important to get this right when you set up. I should have done this last year when I started, but in western Conemara it is a fairly safe assumption to say the soil is acidic.

The veg patch I have laid out is roughly in the "People Love Bunches Of Roses" format for crop rotation and planning - and that is the way I laid out this ideal pH guide, group by group.
As the garden develops, and new crops are introduced, I will update the list in future.

Ideal pH of 4.5 - 6.0.  Soils with a pH lower than 6.5 are best-suited for raising potatoes; the ideal soil pH for potatoes is 5 to 6. In fact, potatoes are one of the few vegetable crops that can tolerate and thrive in more acidic soils — soils in the 4.8 to 6.0 pH range.
Potatoes may not do well in soils with a pH higher than 7, because if the pH level is high, many of the nutrients that potatoes require to grow will not be available.

Beans 6.0 - 7.5
Pea 6.0 - 7.5

Water Cress 5.0 - 8.0
Cauliflower 5.5 - 7.5
Turnip 5.5 - 7.0
Broccoli 6.0 - 7.0
Brussel Sprouts 6.0 - 7.5
Cabbage 6.0 - 7.5
Chinese Cabbage 6.0 - 7.5
Kale 6.0 - 7.5
Kohlrabi 6.0 - 7.5
Spinach 6.0 - 7.5
Mustard 6.0 - 7.5

Shallot 5.5 - 7.0
Garlic 5.5 - 7.5  
Onion 6.0 - 7.0
Leek 6.0 - 8.0 

Jeruselem Artichoke 4.5 - 7.0
Chicory 5.0 - 6.5
Carrot 5.5 - 7.0  
Beetroot 6.0 - 7.5
Parsnip 5.5 - 7.5 
Oca 5.5 to 7.5
Radish 6.0 - 7.0

Tomato 5.5 - 7.5
Cucumber/Gherkin 5.5 - 7.5 
Lettuce 6.0 - 7.0 
Celery 6.0 - 7.0
Cress 6.0 - 7.0
Horseradish 6.0 - 7.0

Rhubarb 5.5 - 7.0
Gooseberry 5.5-7.0
Acid Soil: Apples, Macadamia, Nectarine,Blackberry, Blueberry,Strawberry,Watermelon
Slightly Acid to Neutral Soil: Grapes, Peach, Pears, Apricot
Neutral to Alkaline Soil: Cherry, Plum, Almond 

Quinoa, 6.0 - 8.5
Acid Soil: Oats
Slightly Acid to Neutral Soil: Barley

Pumpkin, squash 5.5 - 7.5
Asparagus 6.0 - 8.0
Mushroom 6.5 - 7.5 

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  1. Wow, very interesting information! Kind of makes me want to start doing kitchen gardening too. Thanks for sharing!

    Hanna HI 98129

  2. Thanks for the comment neo, thats great news, and remember you can always start with just a few salads, does not have to be huge

  3. Good post thanks for sharing .. While gardening it is must to do soil test. Dig a small hole in the soil,Fill the hole with water,Insert the tester into the mud, Hold it for 60 seconds,. A pH of 7 indicates neutral soil, A pH above 7 indicates alkaline soil, A pH below 7 indicates acidic soil. Take several measurements in different spots of garden
    geotechnical consulting services


Thanks for commenting - its cool that you took the time