These a wild (Bird Gifted years ago) local native Black Elderberries. I am lucky enough to have them growing wild in ditches and field edges all over my local area. However those bushes will produce clusters about a 1/3rd of this size.
Even my own native bushes in “the walk on the wild side” food garden which could be considered my control group, will produce lovely flowers, and lots of beautiful small clusters, somewhere between 1/4th to 1/3rd the size of this single cluster shown above.
Now I know that the odds are folks will not like my tip much but I have shared it locally with folks and I get the same feedback from those that are willing to try it, which is that they get crazy boosts to the size of the fruit and fruit clusters.
Farmgal’s #1 Tip for getting loads of Elderberries, when doing yard clean up toss the dog poo, under the bushes, and or, ideally if you can, plant your elderberries on the outside edges of your dog yards. Your elderberries will thank you!
No, any old manure will not do, yes you will clearly get a boost if you feed your bushes be it with plant based composts, worm castings and or any kind of herbivore or fowl manure.. However it needs to be canine, I would love to tell you why but I can’t, I can track that it makes a difference, I can measure out the weight of the berries single and cluster wise vs those that have it and those that do not. That is stat data, and its clear as bell, there is something about Canine manure that Elderberry bushes love.
Strange but true and its so simple, no composting required, no tea making required, just pick up and toss it down and around the base of the bushes a few yard clean ups a season (spring for sure and fall for sure) and let it do its own breakdown and work.
If you love Elderberries, and you have dogs, you have got to try this!
Ps, Zone 5a, ottawa valley area, ontario, canada. Tested only with local native elderberry bushes, 19 years worth of stat data, plus some crazy friends willing to run tests on their own bushes to see if it worked for them as well and yes it did!
Just another Day on the Farm 
Does this work on fruit trees other than elderberries? We can’t grow edible elderberries here (too dry, or maybe too cold, not sure which), but we have plenty of other fruit trees, and plenty of dog doo…
Oh, that’s a good one, I have no idea, I found out about the dog manure when the elderberries went crazy in front of the winter outside dog pen and I have just used it for them ever since. I have never tried it with any other kind of fruit tree etc.
If you decide to try it and get some trackable results, I would love to hear it.
Unfortunately, I tend to be too distracted to be good at tracking results, but I may start assessing possible candidate trees. Not apples, since we sometimes use the windfalls, and not anything low to the ground like gooseberries. I will have to think on this.