I grow Sambucus canadensis which I believe has the same requirements as Sambucus nigra. Mine fruit on new growth and never fruit again on the same wood. So there is no advantage to leaving them alone. I prune back after fruiting or at least by winter and the bushes stay smaller and I get more fruit then I can possibly eat. The branches that bend over are usually full of fruit in my garden. I can't believe that your plants are that big and have not fruited, mine fruit when they are only a few feet off the ground. My #1 variety is 'Adams' which only stops blooming when a frost occurs. I can usually judge how much growth to expect by looking at the current years growth. To harvest fruit I cut off the entire branch. Whatever part gets left behind will sprout side shoot that often grow long and bloom within two months.

Wilting of newly planted shrubs is a common problem - This is a simple watering issue. Potting soils are mostly organic and if allowed to dry out, they are difficult to rewet again. When watering newly planted shrubs, lay the garden hose directly above the roots and let the water trickle slowly into the potting soil. Sometimes a few drops of liquid dish soap per gallon of water can assist in rewetting the potting soil if it has dried out. The soap breaks down the water tension and allows for better wetting. Check your plants regularly the first year to make certain that the soil remains evenly moist. Use your finger to probe the potting soil. If you feel moisture, all is fine, if not, drench the roots as described above. Once your plant is established, it should require little attention unless you experience a prolonged drought. If so water accordingly.

your friend did a really good thing for you ...I never look a gift horse in the mouth....and I never turn any thing down.I can always find a home for every thing even if its not my ownI love growing things and often I will start somthing and see that a friend has the perfict place for it and so I dig it up and transplant it ...befor they can say yes or no ...cuz I know I was right and so what if I have to come over and visit the plant ,good excuse to visit and have a cup of coffie or tea and I havent had a friend say I dont like the plant or its in the way .and only had 1 that got the lown mower treatment ..and that is becouse I told them if they wanted it to spread ...that would be the easy way to do it .LOL no I am not one of those ppl ...I just know the few friends I have very very well .

Elderberries are the only berries I have managed to get picked this season, daughter was in an auto accident June 19th and her rehab is 3 hours away from home. The berries in the pic aren't all ripe, did you remove the green and underripe ones? Unless you net it's tough to fight the birds by the time they get fully ripe. I like to pick them when the stem on the cluster is also purple and hanging down from the weight of the berries. I lucked out this year, along the road down the hill are 2 huge bushes and the berries are nice and plump, there are enough on those bushes for the birds and myself. Picked about 15lbs so far. Since I was a little kid I have made Elderberry Jelly and now I also make a syrup for winter coughs and colds that is added to tea. Freezing the stemmed berries sure make for fast destemming of the berries and your hands don't get purple. The berry mash, in the past, I have used for wool dye. Too chicken to try to make wine and I think they are way to seedy for pies or jam.