Depends on what your soil pH is. Most plants prefer a slightly to moderately acidic soil so liming is often not necessary. I would shoot for a pH in the 6.3 to 6.5 range - that will accommodate a HUGE range of plants. If things are growing well now, you likely need to do nothing other than more compost if you wish....it's hard to overdo compost since it continues to breakdown and disappear over time.

in other words.. you start by having a professional soil analysis done.. so you know where you are starting in regard to your actual soil ...

they are usually done by the state Ag college.. which is usually the one that ends in STATE.. as in MI STATE ...

call your county extension office.. and they should be able to set you up ..

ken

i swear i wrote this post last week .. is it already off page one???

FWIW, determining what your native soil pH is does not require a professional soil test. It is probably the only home soil test that can be done with a relatively high degree of accuracy as long as you follow instructions and use distilled (not tap) water. But having a professional soil test done - at least a baseline test - is not a bad idea anyway. It will provide a marker from which to determine what type of amendments may be needed going forward.

In my many years (almost more than I'd care to admit :)) of gardening I have only had a pro soil test done once. After that, all I did was to add compost on a pretty routine basis to replenish organic matter and nutrient levels. Since my area tends to have the preferred range of slightly acidic soil, I have never limed anything nor needed to but I have occasionally added acidifiers to lower pH for specific plant needs.

since pH .. and correct me if i am wrong.. is an exponential scale .. it is near impossible to actually change it permanently ...

so for the most prat.. one GOOD test ... is all you need ...

since you cant permanently change it .. in all reality ... all you need to know.. is if you need annual applications of something to adjust it ...

frankly tim.. if your plants are growing just fine.. i dont know why it is an issue..

are there any facts to show that there is some negative impact to your plants???

ken

I have acid soil (loamy fine sand), enough so that blueberries grow wild. I add compost to my perennial beds and use wood shavings as mulch. I grow all the plants you named (though fern is quite vague as some like acid and a few more alkaline soil) and have yet to have any issues. If you have soil that's too acid for what you are growing, the plants will let you know that they are unhappy. I don't try to grow ornamentals that need pH above 7 since I don't want to fuss that much over plants in a situation they don't like.

However, I do lime (or more usually use wood stove ash) to raise the pH of my veggie garden since my soil is too acid for many veggies to be happy. It is pretty easy since I do it annually when the garden is empty, most often in spring since that's when we have the most wood ash, but sometimes in the fall.

Ken - you are correct in saying that pH is exponential so that 5 is 10X as acid as 6.

If it ain't broke, don't fix it.