Allotment Gardening Advice Help Chat
Growing => Grow Your Own => Topic started by: Jack Child on April 15, 2021, 23:57
-
Hello everyone.
A couple of years ago we took up a load of turf from under a big pine tree. The turfs were full of pine needles, so we put them in a crate upside down, and it has now turned into a lovely compost consistency, albeit riddled with pine needles at various stages of decomposition. I was thinking it could be good for growing tomatos, aubergines, peppers etc in pots, if mixed with some normal compost or well rotted manure. I'm just conscious about it being potentially too acidic from the pine needles. Any ideas?
Thanks, Jack
-
Believe I'm right in saying that even quite naturally acidic materials finish up more or less at neutral pH when fully composted - your material is clearly not quite at that stage yet.
I'd use a chemical pH test kit before using it, bearing in mind that any excess acidity would be reduced by mixing with other more neutral compost. Tomatoes prefer a slightly acid soil - 6-6.8, which would also suit peppers, so with any luck you might finish up in the right area.
(Don't rely on those cheap 'probe' pH meters - they appear to be mostly wildly inaccurate.)
-
Hi Jack
I wouldn't be too concerned over those pine needles and acidity. The soil pH tomatoes are adapted to is pretty broad, roughly pH 5.5 to 7.5. The pH JayG mentioned is in the middle of that range.
My vegetable garden is all on land that was pine forest until recently. The soil here is acidic naturally, with or without pines, because all of our soil developed on acidic rock (granite and gneiss). Pine needles are all throughout the soil.
I don't worry about acidity, but I am concerned the tomatoes get enough calcium. Depending on calcium source, calcium can raise pH (by adding lime or dolomitic lime) or can change pH relatively little (by adding gypsum or plaster of Paris; or adding calcium nitrate). The added calcium will help prevent blossom end rot.
I agree with JayG that it is a good idea to check soil pH, as pH can change nutrient availability. I also agree cheap pH probes can be wildly inaccurate. Use a test kit meant for soil, or send a sample to a soil lab for testing.