Q.I Have A 3yo Elderberry Shrub And It Never Flowers. Does It Need Fertilizer Or Something To Bloom?
It’s in an 18 gallon bucket with drainage holes on the bottom/sides. 75% sun. Gets plenty of water (has lots of new growth and in fact sent up a fourth stalk at the far edge of the bucket this year, so it seems healthy…) Just to clarify … I see a lot of questions about berries and pollination but mine is about flowers. I’m not getting flowers or buds at all.

Certified GKH Gardening Expert
It sounds like you have all the cultural needs. Elderberries don't normally need much fertilizer, but since yours isn't flowering, next spring apply a slow release 10-10-10 fertilizer. You might also consider having your soil tested. There may be something amiss. You can enrich the soil with compost or manure right now. Make sure the container is very well draining as elderberries do not like wet feet. They also prefer cool and moist to hot and dry, which you may experience in Texas.
Pruning will benefit the shrub as the older canes are less productive. These articles should help:
https://www.gardeningknowhow.com/edible/fruits/elderberry/pruning-an-elderberry.htm
https://www.gardeningknowhow.com/edible/fruits/elderberry/elderberry-bush-varieties.htm
https://extension.unh.edu/blog/2020/08/what-best-way-grow-elderberries