No real way to adjust it that doesn't take time - months. And trying to do it after planting usually only creates more problems for the plants.

Besides most plants can live and do fine with a pH of 7. Sure it isn't perfect but it is tolerable. I have to work very hard every year to get mine down to that level. So you are better off leaving well enough alone. Just compensate as needed with a bit of quick acting liquid nutrient supplements.

If you feel you really MUST do something then content yourself with working peat into the soil as you can without disturbing the plant roots. It isn't fast acting but will gradually knock it down a tenth or 2.

Dave

PS: and no more wood ash...ever. ;-)

Concur: tomatoes tolerate a very broad pH range.

Perhaps you could use some peat moss as a mulch.

Linda

Take a deep breath. As noted, tomatoes do fine in a large range of pH. Trying to manage a pH on the right side of a decimal point is, er, pointless. My pH is around 8 (and my water is similar, so acids get quickly neutralized) and I have zero problems with tomatoes. pH management at that level is really a distraction. There are more important things you could be working on, perhaps revealed by your soil testing.

I used to garden in Santa Cruz. Been there, done that.

Sulfur is cheap. I use it about every second year to keep PH below 7. Otherwise, my garden goes to 8+.

I concur with Dave and Farmerdill. Tomato plants can thrive in wid range of pH, including 7 and even 7.4. The experts say that the optimum pH level is 6.8. So then 7 is not too far off.

Another thing is that altering pH (up or down) take time and the best time to do it off season.

Sey