20 types.. or twenty of one kind.. you have a monoculture there.. and that might be complicating the disease issue ... if any

doesnt matter ... check the link.. and start pruning them properly ...

it states that branches only produce for about 3 years.. and then are cut down near the ground ...

no personal experience from me... other than having an old monster that i would hack on.. whenever it would get out of hand ... i never used it for production ...

there is a fruit forum.. and i have never seen those 'sperts over here.. and they may have more specific suggestions...

you will need to fully ID the malady ... and proceed accordingly .... it MIGHT be overly mature wood ... which just needs to be pruned out ..

but in case it isnt.. you might want to learn how to sterilize your pruning tools in between bushes.. so you dont go spreading it further ...

good luck

ken

Here is a link that might be useful: link

Just growing 20 assorted specimens of a single genus does not necessarily a monoculture make :-) That would depend far more on planting a single species of that genus in close proximity and without integrating any other plant types. I'm not at all sure that's what the OP is describing.

I would not consider them to be at all like a Ceanothus. Sambucus prefer an organically rich soil and even moisture, conditions the ceanothus tend to abhor. They can tolerate other, less favorable soil conditions but would appreciate regular irrigation in summer in areas that tend to be dry. But elders can and often do have problems. What you are describing could be one of several issues: cankers that can girdle stems and cause dieback, borers, viral diseases or possibly some sort of root rot. They do appreciate hard pruning and that is often required to keep the plants looking tidy. Cutting off diseased stems at ground level is a good plan - these are suckering shrubs, so should send out new growth as long as roots are healthy. And the cautions about sterilizing pruners are sound.....you don't want to spread whatever the issue is from plant that may be infected to another that is not.

Some of the more ornamental selections tend not to fruit very heavily and planting several different clones could encourage better fruiting. FWIW, I've never seen 'Black Lace' set fruit, although it flowers heavily. Same with a 'Sutherland's Gold' I grew in my old garden......lots of flowers, little if any fruit :-) In my area, the native Sambucus caerulea typically produces prolific clusters of fruit.

Other problems include a tendency to powdery mildew and aphids.

HTH

Thanks for the thoughtful replies. I've not seen anything that looks to be girdling the stems, nor sign of borers, powdery mildew or aphids. That leaves root rot and viruses.

I'm going to try the suggestion of cutting down to the ground.

These plants are watered by drip but perhaps they are not getting enough.

I think there were berries once but since then I've not noticed any more nor flowers. That that might mean that I just didn't notice them though.

drip irrigation or weeper hose?? ... one has a predictable water flow .. and the soaker hose.. especially at long distance runs is unpredictable .... run the water.. and then go insert your finger.. and find out how water is moving thru your system ..

now mine.. was NEVER watered.. and NEVER EVER FERTILIZED ... and was an heirloom .. and berried every year ...

are you fertilizing??? too much of the wrong fert can cause a flowering plant to produce too much green to the detriment of flower, and eventually fruit ...

good luck

ken

Hi Ken, thanks for your response and sorry for the long time to reply back. I can't keep up.

I've not fertilized them at all. I looked at some links and they say to cut them back to 1st and 2nd year growths, cut out the third. Now if I can just tell which canes are 1st and second yr... Also some say to cut back to maybe 5 canes per plant. These ones have maybe two dozen each. Maybe it's just that they've never been thinned to the ground. Maybe most of them are just old canes. Seems like the best thing would be to just cut them all to the ground then let what comes up come up.

Oh, sorry, they are on drip not soaker hose. I seem to get conflicting suggestions on how much water they need. The ones I see in the wild of course don't get regularly watered. On the other hand they are on mountains and mountains are like giant sponges.

What made me think that maybe it's the soil is that there were also a bunch of flannel bushes, maybe 10 of them about 150' away planted in a row. Anyway most of them died in the past year and I have no idea why except perhaps too much water. Maybe something in the soil or maybe the siting isn't right. Starting to get paranoid about what's going on.

By flannel bushes do you mean Fremontodendron? If so they are pretty drought tolerant and very sun loving - along the lines of Ceanothus but a little more tender I believe. Not the same as most elderberries. Although they are 150 feet away they might be getting too wet. But also, although I am not familiar with your climate, could it just be too cold in z7 for Californian natives to thrive?? Just a thought, since I don't know where you are exactly.

Regarding flowers/fruit. The elder I know here (Sambucus nigra) fruits on old wood, ie more than 1 year old. So if you are cuttting them down annually you will never get flowers.

Yes, Fremontodendron is generally listed as a zone 8 or 9 plant - zone 7 may very well prove too cold for any long term survival. It is considered just borderline hardy here in my zone 8 climate. And as flora notes, it is much more closely aligned with ceanothus as far as cultural requirements are concerned as well - low fertility soil, excellent drainage and minimal watering. It also tends to be similarly short-lived.

FWIW, both the elder and the flannelbush are susceptible to verticillium wilt, a soilborne fungus that attacks the vascular system of plants and can easily result in the dieback and/or death of plants such as you describe. And it is rather easily transmitted from plant to plant by mechanical means via contaminated garden tools, like shovels or pruners. Taking samples of the affected plants to your local extension office for diagnosis might be advised. They can also enlighten you on how to deal with this rather widespread pathogen.

Zephyray,
My experience in the mid-Atlantic has been with S. canadensis. They're pretty common here, found in both saturated soils of wetlands and dry soils of fence rows and road banks. I have a particularly nice, arching shrub on the stream bank near my home, 10' tall, 12' wide. It is untouched by human hands! Each Spring it is a white mass of flowers, followed by gigantic, heavy clusters of black elderberries. Since I don't care for the flavor, the birds get them all.
My suggestion would be to resist the urge to prune your plants, you will incur the wrath of the witches :), see link.
Sam

Here is a link that might be useful: Elder Fact Sheet

Thanks for the comments.

flora uk, I've cut them back about halfway for the last couple of years.

gardengal48, I would think that if it were the cold that they would be dying in the winter or early spring, but they seem to be having the biggest problem, leaf drop, looking bad near the end of summer, early fall.

sam md, well if they were doing fine I wouldn't be thinking about cutting them.

OK - I think that if you are cutting them off half way then it is quit epossible you are cutting off the wood which would otherwise have flowered. it needs to be in its second year to produce.

I also reread the original post and the description of the inside of the wood was interesting. It's a bit hard to envisage but the inside of elder stems, at least S. nigra which is the one I know, is not green, it is a whitish pith. Elder used to be used to make whistles and pea shooters precisely because the twigs are essentially hollow once you have pushed the pith out. Is that what you were seeing and thought it was dead wood? Just a thought.

Thanks flora. That makes sense then that the reason I haven't noticed flowers or fruits is because I've been cutting all of the canes off. I think I can tell which is the first year's growth since those canes are thin and look healthiest, but how do I tell if the others I am cutting are second, third or later years growth?

I did see the white pith inside and green coloring more close to the outside on the living ones. The inside of the dead or dying ones though are brown with no or very little green. The canes and leaves on them, if there are any leaves left, are withered and the inside after cutting also looks either very dry or wet.

Do you or others think that my thought to just cut them all down to the ground to invigorate new growth then start keeping a better watch on what comes up in the future and cutting down all third year growth is a good idea? Should I try to limit new growth to 5 canes per plant as I read somewhere?