Answer: Daylilies are usually trouble free but browning leaves at this time of year is not normal. Inspect your plants for insects (thrips or spidermites) and dig one to check for root rot. Overly wet soils (poor drainage) can cause problems with the roots. As for your petunias, slugs and snails love to eat the tender petals and little bud worms can feast on the unopened flower buds. Check around the plants for signs of slugs and bait if necessary. If your plants have unopened flower buds look for tiny holes which indicate bud worms. The botanical Bt (sold as Dipel) is effective against caterpillars but they must consume plant parts treated with Bt before it is effective so you'll likely see more damage. If you find no evidence of slugs or caterpillars and your plants simply are not producing flower buds at all, then I'd suspect a cultural or environmental problem - not enough sunshine or extremely hot weather can both keep petunias from producing flower buds.
Hope this information is helpful!
Q&A Library Searching Tips