After consulting with the seller who I bought some of the bulbs from, I learned a few things about better care and growing tips for tulips. I will be amending the soil to make it lighter so it will not compact over the bulbs. I have read that tulips bulbs like a sandy soil. As an alternative, I can use perlite. This will help with drainage as tulip bulbs do not like sitting in wet soil. If I decide to plant them again in the rectangular planter, I will drill more hole at the bottom.
The seller recommended that I feed the bulbs and flowers with a water diluted fertilizer instead of using compost. I'm not sure why she recommended a liquid fertilizer. I am guessing that it may have been too much nutrients and/or that compost compacts, which I have noticed.
And aphids apparently love tulips especially the leaves. They infested and attacked my ailing tulips; growing colonies were found on the underside of leaves. It was a frightening sight. They really do serious damage to tulips if not proactively dealt with to get rid of them. The seller explained that aphids attack weak plants. I think there is some truth in that. I have read that aphids like to cling to new growth. New growth is more vulnerable and can be easy pickings for pests like aphids. I have seen clusters of aphids gather on my mini rose plants wherever there is new growth.
I know it's possible to grow tulips in containers. There are tons of blog posts and articles about growing tulips on containers. However, the seller mentioned that certain varieties are harder to grow in containers like the parrot tulips. Despite the warning, I plan to try again. One parrot tulips popped out of the container and blossomed. I know it's possible. Difficulty will not deter me.
Another lesson I learned is that tulip bulbs are susceptible to mold during storage if not clean of dirt and allowed to dry completely. The tulip bulbs I was able to recover were beginning to be covered with white mold after storing them in paper bags and kept in a cool and dark room. I decided to dispose of them. It wasn't a huge loss for me as I'm not sure they will return next year given how their leaves dried up sooner than normal because of the aphid infestation.