It's not toads. Not regular ones, at least. Toads whistle to find mates but it's more of a reverberated tremolo than a whistle and you definitely wouldn't confuse the two. My wife and I had to relocate over 50 toads that had bred in puddles on our pool cover because that many toads, all calling every night, was like a coach's whistle hooked up to an amplifier. We couldn't sleep at all. So, we caught every last one of them, drove to an isolated pond 5 miles away and dumped them all in. We haven't had the problem since. The Gray Tree Frog also has a trill tone, but it's call is so powerful that from a distance, it can sound like a spooky nearby whistle. The Spotted Owl has 13 different calls, one of which has been described as an eerie whistle. If the pitch has a sudden upturn near the end, this could be your culprit. It really depends specifically what your whistle sounds like. Good luck finding your answer!

The yellow color with the veining is classic chlorosis, which is almost certainly caused by an iron deficiency. I don't know anything about Grow and Bloom, but check to see if it contains iron. Potash won't hurt anything, but I don't think potash is your problem. A potash deficiency usually shows a fairly uniform olive drab color without the veining on the hyacinths. Potash deficient hyacinths usually have really long roots as well. Nitrate won't hurt anything either. I don't think you really want to add phosphate because of the algae risk. Add iron. Find a chelated micro-nutrient mix, like Fertilome Liquid Iron. You should see improvement within a couple days. Go ahead and add some potash too. It won't hurt.

The next morning not much has changed with the alien worm but it's got friends now. Here are some pictures of the others. One is growing horizontally under the ground. I guess that answers the question of what I'd find if I dug one up… nothing. Lots of flies over in this area now.

You wouldn't be the first to go into the industry after retirement from some other career. Interior landscapers - also called interiorscapers, or commercial plant care co's - are the people who care for all the plants in commercial situations - the offices, lobbies, hotels, restaurants, airports, etc. Sometimes those places employ the interior landscaping co to install and care for the plants, sometimes they have their own full time 'scaper to care for the plants in their facility. The industry is called Interior Landscaping. If you're interested, this is an interesting history: http://www.manyhatspublications.com/article-145.html There are several websites for plantscapers which are often for professionals only, but you can easily join if you're looking for information; this is a good one: http://www.newprocontainers.com/blog/ You can also google "plant care companies" in your area if you'd like to talk to some professionals.