I have a fascination with brugmansias ("brugs" to those gardeners who grow them.) They have the most beautiful and spell-binding flowers. They are also very easy to grow indoors or outdoors in the summer.
I got mine as cuttings in the mail. I traded someone for them in Sept of last year. Cuttings root very easily in water but only if the water is warm. If you let the water get cold, they will not root. It is important to keep the cuttings in a place that stays fairly warm most of the time. Unfortunately, in mid winter or late fall, that can be difficult for some people. You can always use a heating pad on low, with a few towels folded on it for warmth under the water. After a few short days in warm water the cuttings will develop pre-root thingies (its an industry term) on the part in the water. They should look like this:
After these have developed you can safely plant your cutting in slightly damp potting soil. Keep the cutting fairly warm and only slightly damp. Too much water will cause it to rot and too dry will kill it. Brugs do not like to dry out at all, so just keep it constantly slightly moist. I have not had a problem with mine. When they look a little wilted, I water them. I usually end up watering them about the same as my other houseplants, after they have started growing.
I keep mine in the kitchen by the south patio door. I empty the day old coffee into their various pots every morning and dump the coffee grounds into their pots. They seem to like it.
After a couple of weeks you should have some leaves sprouting. Put the cutting in a sunny area throughout the winter. It doesn't have to be a south window, just an area that gets some sun. The goal is to keep it alive until you can put it outside in the spring, after all danger of frost has passed.
After they have started actively growing, feed them weekly with a very mild fertilizer solution.
I kept the growing new plants in the kitchen all winter long. By the time spring came along they were this size. Your brugmansia will triple in size outdoors in the summertime.
When all danger of frost has completely passed, they can go outside. Up here in the north, they do best in full sun. Down in the southern states in the extreme heat, they do best in a fairly shady area. Half shade is ideal.
When they are actively growing they need a lot of fertilizer. They are heavy feeders. I almost think it is impossible to overfeed them. I use time release fertilizer in the spring and apply it liberally into the soil and the planting hole where my brugs are going.
They will grow at an alarming rate with good light, lots of fertilizer and enough water. They don't like to dry out completely and will wilt readily if they need water, and they need a lot of it. If given the right conditions, you will be rewarded with the most fantastic blooms you have ever seen. I started my cuttings in September 2008. I got my first bloom in October 2009. This is it.
If you live in the great white north, as I do, you will need to do one of two things with your brugmansias in the fall. You can either dig them up, plant into very large pots and bring indoors to be grown as houseplants; or you can dig up the root ball, put it into a pot or plastic bag, water and keep in the cold cellar, cold, unfrozen and dormant until the following spring.
When spring arrives and all danger of frost is past, it can be planted back outdoors again. You will need to harden it off and put it outside gradually.
If you start your cuttings now, perhaps you can get blooms by next fall too. If mine continue to grow indoors. I will have some cuttings to trade soon. If you are interested in a cutting from the pink one pictured above, please send me an email.
This is what I am hoping for from my mature brugmansias next summer. These photos are not mine. These magnificent plants belong to someone else, but there is hope for mine next year!