For several years I’ve had a vexing problem growing morning glories. I buy the seeds for the ‘heavenly blue’ variety. Soak them overnight, plant them in a sunny southern spot where they grow vigourously. But when they open their blooms, the flowers are small, and either pink or purple. This wasn’t always the case– for about 4 years I was successful, then 5 years ago, something changed. I have tried buying seed packets from different companies and different garden centres. Makes no difference. This spring, I even dug up the soil to a depth of 12 inches and replaced it with fresh, bagged soil. Again, the vines were growing well. Then, yesterday morning, the first flowers bloomed and… you guessed it: small and purple. What gives?