Strong sedative tea: California Poppy Seed Tea.
Mind its not the same sort of chemistry of opiate poppies. And its not opiate latex (from which heroin, morphine and other interesting drugs come from.
There is a minor risk that you will test positive for opiates from California poppy seed tea. You would have to chug a few gallons of it in order to increase that risk higher than positive test for poppy seeds on buns.
I use California Poppy Seed tea for both chronic pain relief and to assist me in sleeping more dreamless sleep (trust me, we do not want Bowyn dreaming, it rarely ends well).
Other herbs I use to improve sleep:
I typically mix up one gallon batches of tea. More often than not I use dried product.
The ratios I use vary depending on flavor.
However a good ratio for Chamomile and Catnip is 1 to 1 - I use a teaball, it holds about two teaspoons of dried crushed herb.
I preheat the pot/container I'm going to seep it in and add 2 cups of boiling water. I will add honey, or a few mint leaves, or a few lemon balm leaves for added flavor. once the tea is cool I sieve the contents through a paper coffee filter, then add water to make a gallon.
I drink it either hot or cold. Heating it for a cup of hot tea
For California poppies I use a (one) seed pod. mind when I harvest I cut the stem about one inch below the dried ball (before it bursts open). When I use it I gently crush the ball to release the seeds, and then drop into a preheated tea pot, then add 2 cups of boiling hot water. I let it seep until the water is cool to the touch, and use a paper coffee filter to strain the liquid to remove the soils.
With that two cups of water I add 1/4 to 1/3rd raw honey, and add water to make a gallon of tea. I refrigerate it. either drinking a glass cold, or heat a cup in the microwave about 2 minutes on high.
I occasionally make the tea stronger, in this case its just seeping the same amounts with 2 cups of boiling hot water, then drink it without adding water.
This last I do when my pain is 'through the roof' and I know I won't be sleeping well.
DISCLAIMER: Herbs do not = safe. Some herbs may actually counteract other prescription drugs or be dangerous if used in combination with alcohol or sedatives, and others may be dangerous when combined with antidepressants.