Not sure where you might have read it but pine needles do NOT poison the soil!! Pine needles (pine straw) are a very common garden mulch in many areas!! Nor do they make the soil any more acidic than it would normally be - both of these are garden myths. The reason many plants do not thrive under large conifers like pines (or even larger deciduous trees) is usually a combination of dry shade - a tricky gardening situation at best - and root competition.

Look for spreading groundcover type plants that will tolerate or thrive in these conditions - fernleaf dicentra, epmediums, bigroot geranium, just to name a couple. Start out with small plants and give them some extra TLC (water and even some ferts) until established.

Glad to know those pine needles aren't poisonous to the soil. You're right...I have planted things and forgotten to water them. Thanks for the suggestion of plants, though. I'll work on those. Heidi