Neil Sperry is on WBAP from 8-10 on Sunday mornings.
WOAI in San Antonio on Saturdays from 7-10 you can find on iHeart Radio on iPhone or iPad. The main person on this one is David Rodriguez, Bexar County AgriLife Horticulture Specialist.
Not sure when Howard Garrett or Randy Lemmon (Houston) are on. I catch them occasionally when traveling on weekends.
Oh, and John Dromgoole - Garden Naturally is on KLBJ in Austin from 9-11 on Saturdays and 8-10 on Sundays.
Hey Dave, I think you and Trish should start a radio talk show!!