Hi, Kathleen, thanks for your question about pH testing. The only way to get really accurate pH information is laboratory testing Analytical Laboratories Serving Oregon. It's good to get this done at least once (and also to test for nutrients – very important, as there may be deficiencies OR excesses) so you have an accurate baseline. However pH varies naturally through the year and over time, and most plants are tolerant of a pretty wide variation, so absolute accuracy is not usually essential for typical garden.

For testing on a more regular basis, over the counter test kits are OK. There has been limited research comparing them, but Rapitest seems to be good, and I personally have used it. This type has you make a soil solution, then match the color to a color strip. Test strips like Garden Tutor (which I have also used, but don’t have any research on) also require a solution, but then you dip the test strip in it and match that to a color strip. Both are easy to use (as are other brands), but also have the drawback that, if your soil has a lot of color, it may discolor the results to the point it is difficult to make a good match. You can use two different ones and see if they both give about the same results.