Adding gypsum at the recommended rate each year for at least 3 yrs. will help. BE PATIENT. Also, move the emitters out to about a foot beyond the drip line. This will cause the roots to move outward.

Adding gypsum at the recommended rate each year for at least 3 yrs. will help. BE PATIENT. Also, move the emitters out to about a foot beyond the drip line. This will cause the roots to move outward.

Should I rototill/loosen the sand up outside the drip line on the trees to mix in the gypsum? If so, how deep should I go?

I did something similar to what you've suggested in irrigating a honey locust that I thought was a goner and it worked (no gypsum). It was a stick with a few leaves on it for the first 18 months and suddenly this year, it's a little tree. The difference with the pines is that they're a lot bigger, healthy looking (though stunted) and more expensive than the locust.

Thanks so much for your help.

Pines have surface roots - tilling will damage them.

Just spread the gypsum liberally on the ground around the trees, and water it in thoroughly. It's slow-acting.

And the advice to move the drip lines out is absolutely correct ... you want the roots to have a reason to leave that "flowerpot" they are planted in.

One addition to lazygardens directions, loosen the soil to a depth of 2-3 inches either before or after applying the gypsum and then water in slowly (do not allow runoff).