Hello Permaculture Friends, I live in the Andes, and there we have a lot of ferns, I guess because of the acid soil caused by all the rain. We already put limestone to increase the pH. Some Farmers here say that the ferns making the soil even more acidic. Can that be true? Are there Plants that make soil more alkaline? Thank you for your advice. The Rainbow Community
There are some trees that will create a bubble of higher pH around their roots but this isn't going a affect a large area unless there are lots of the trees. Moringa and some of the white oaks have been found to have the exudates that will change slightly basic soil to more basic soil (usually by around 0.2 points) Lime is good for a fast change in pH and if you can include gypsum then the effects will last longer than just the lime. If you have acid soil loving ferns, changing the pH of the soil to just above neutral (7.2 to 7.5) should create a habitat they can't survive in, but be aware that such a pH will not allow most food plants to thrive (these usually prefer a 6.8 to 6.5 pH but can survive into the 7.5 range).