Sempervivum and Jovibarba forum: Semp woes in zone 7b NC - any advice welcome!

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Name: Wren
Wake Forest, NC (Piedmont) (Zone 7b)
Sempervivums
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ZenAndCoffee
Jun 20, 2017 2:50 PM CST
I know most of you are in different climates from me, but maybe someone can offer advice - especially if it's not a matter of climate. Darn this crappy NC weather lately though, lol.

Do semps take in water through their leaves at all from the air? I know most comes in through their roots but I've been having casualties lately where the semp appears to be rotting from the crown. When I uproot the affected ones the roots are dry and healthy but after removing any leaves with dark discoloration at the base I see that part of the meristem (is that the correct term with semps?) is sometimes part rotted/discolored near the top vs the base, right under the affected leaves. I *think* I've saved a few by cutting out any signs of rot - they aren't pretty but hopefully they'll grow some offsets. On a few I've also found signs of a white mold?? right by the affected area. Not all of mine are having this issue, nor are any I received earlier in the year around March or April. My latest ones also seem fine, but were planted a little differently as I've gone over below.

A few notes to give you an idea of the environment :

After having a few fail after being too close to the screen on my porch overnight during an unexpected rainstorm followed by a very hot day I repotted each in 1" deep chicken grit top dressing vs the half inch I was previously using.

The soil below the top dress is cactus mix cut with Perelite, a little paver sand (the bigger particle stuff), a little pea gravel and more chicken grit. Most all of mine are smaller starts so I figured the deeper grit top dressing will help them establish themselves by sending roots on their own down to the soil. The ones I've received most recently went directly into this new setup and seem to be doing great so far.

I've switched to watering only with crushed ice early in the morning when I water - never on the semp, but on the grit around it. They are all in well draining plastic pots or plastic free standing raised beds with feet on them to allow air underneath. I've also drilled a few holes in the sides to increase airflow to the soil.

They are all on my screened porch which gets morning sun and then heavily filtered afternoon sun as I also learned the hard way that any direct afternoon sun here in the summer is too much for many of them, especially if they are younger starts. Once established that might change of course, but until then when I can go ahead and plant them in my beds this is their setup. I have a ceiling fan on at all times to keep air circulating.

Now here is the kicker. I'm in zone 7b in NC, and we've been having the craziest weather this year. It's been mid to high 80s lately and many rainstorms off and on since April. The past 2 weeks we've had rain everyday during at least part of the day. Humidity is higher than we've had here in a while - for instance today it's 72-78% humidity and 78-80 degrees with very overcast skies. Nights have been around 63-72 degrees depending. I haven't had any new casualties (outside of my Viking and Virgil Ford that bit the dust for what seems like no reason at all) but I want to make sure I keep it that way. Normally we do not get near this much rain.

So now my question is are they actually getting enough moisture through the air right now that they don't need any watering? Or at least not during periods of high humidity? I've read that young starts actually need more water than established semps, but maybe they are getting almost all they need from the humid air? With Virgil Ford and Viking I almost wonder if the humidity alone is what did them in given that the roots looked completely healthy and only the top areas were affected. I have checked and can find no pests and I also treat with a systemic to avoid bringing in new pests that might originally go unnoticed. I am not 'watering' daily or heavily (only a little crushed ice), nor on days when it will rain before late afternoon despite begin on a covered porch. They are not getting wet when it rains either as I move them back away from the screens to avoid that.

I'm just at a loss. While I *think* I finally have things under control I just want to try and get to the 'root' of this rot issue so that I can make sure I avoid it later and so I don't possibly lose any more semps to it, or in turn to under watering for fear of it continuing. I'll see if I have any I can take photos of. Most I already did surgery on in attempt to save but I think I left one Viking to try and 'dry out' to see how that goes as well.

Sorry for yet another long post lol, and thank you in advance!
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Name: Lynn
Dallas, OR (Zone 8b)
Charter ATP Member Garden Sages I helped plan and beta test the plant database. I helped beta test the Garden Planting Calendar I was one of the first 300 contributors to the plant database! Plant Database Moderator
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valleylynn
Jun 20, 2017 6:30 PM CST

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Can you give us photos Wren?
If they aren't getting enough water you will see the leaves start to wrinkle and the rosette start to close up. The rosette closes to conserve moisture. If you aren't seeing any of this, then you might be keeping them to wet. Is the soil moist? Are you seeing any new tiny white roots starting to grow? The rot sounds like a humidity thing. I think I might try watering in the cool of the evening, giving them time to dry out by sun up the next day.
Name: Greg Colucci
Seattle WA (Zone 8b)
Sempervivums Sedums Plant Lover: Loves 'em all! Cactus and Succulents Container Gardener Garden Ideas: Level 1
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gg5
Jun 20, 2017 7:36 PM CST
I agree with Lynn, and I don't think they get enough moisture from the air, it does sound to me like under watering. One thing I do is water less amount but not less often, so if they seem dry, water every other day during high heat, but a smaller amount of water than usual.
Are you sure the "white mold" isn't mealy bugs? When they're little they can look like mold. A close up pic of the mold might be helpful. I was thinking it could also be salt residue if you're watering with fertilizer or hard water... Just guessing at possibilities
Shrug!

Name: Brian
NW Pennsylvania (Zone 5b)
Bigtrout
Jun 20, 2017 7:48 PM CST
Im up in NW Pennsylvania, we still gets bouts of the East Coast humidity, but we get good breaks from it all summer, im a newbie too but in our recent humid bout, I did not water(well at least until the storms blew thru and rained sideways in under my covered deck). I kept a good eye on the soil, if it felt the least bit damp I didnt water them. You sound like you have had humid damp weather for weeks, and although the roots may be ok and your soil well draining, the hot weather may be evaporating the water back out of the soil making it even more humid at plant level right on top of the soil causing the tops to get a bit of rot.
It sounds like your soil mix is good, and air circulation is always a good thing, another thing to look for would be some kind of pest, although I havent had any on my deck, a few of the rosettes of the old type tectorums on my bank get leaf damage from slugs. The slugs dont eat the leaves outright but they do puncture them and cause damage and the damaged leaves slowly rot and die. If some type of pest causes some kind of damage, it may be enough to allow the rot to set in.

And I agree with valleylynn, when I do water I try to do it in the evening an hour or two before dark and I try not to soak the rosettes so they dont act like water cups holding water all night.
[Last edited by Bigtrout - Jun 20, 2017 7:59 PM (+)]
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Name: Judy
Mid Atlantic Coastal Plain USA (Zone 7b)
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MariposaMaid
Jun 20, 2017 8:14 PM CST
Wren I am in a very similar situation and zone weather pattern so will be eagerly awaiting replies to your situation. I'm all ears!

I have noticed that dew tends to collect on the innermost tightest rosettes.
Name: Wren
Wake Forest, NC (Piedmont) (Zone 7b)
Sempervivums
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ZenAndCoffee
Jun 20, 2017 9:31 PM CST
Definitely not mealies - or at least I strongly suspect not (though it wouldn't be the first time I was surprised and wrong lol!). I battled both the root type and the wooly above ground type with my first semp order ever. I quarantined them for a month and a half and they went through an alcohol dip, then a systemic dip, new sterile soil and then 2 follow up waterings of systemic. They are still separated from my other semps just in case for the time being. In other words though I'm fairly certain that's not the cause here. Not to say that I'm not about to go back and check first thing in the morning though lol! I also treat all new comers with systemic, so hopefully it's doing its job. I inspected the affected ones pretty closely and didn't see anything pest wise. They are in a closed screen porch, so while some things can get in I'm sure, it's unlikely that slugs etc are doing any damage and I haven't seen any damage outside of the random rot. I did get a few semps in not too long ago that had a bit of sticky white stuff on some of the dried under leaves that I removed, but they had no signs of actual mealies and got systemic treatment as well.

The mold or fungus is only in a tiny area on the affected semps, right at the base of where the rot seems to be. It's not on any leaves - just the meristem at the trouble areas. Not all the affected ones had it though. Definitely a weird occurrence. I just hope it doesn't turn out to be mealies somehow after all. That was one battle I really never wanted to face again lol!

Mine aren't closing up and curling into balls, but some do push themselves up, curling the other way. However the soil feels dry and the roots in the affected ones are dry. All of mine, including the affected ones have sent out new white roots as well. The rotting leaves are soft and limp.

I almost wonder if when I do water that the damp soil evaporates up into the crown as was mentioned and the chicken grit is holding that moisture in at the base. The underside of the meristem isn't getting soft or mushy though, nor are the roots. I haven't watered with fertilizer in a while, and I don't have hard water here. The white 'whatever it is' is fairly localized in one tiny area of the semp and no where else.

The last time I watered, I actually did do so at night since it was supposed to rain in the early afternoon. However recently it's been raining almost every night. It's still a little humid then, even though it cools down, so do you think it would still be fine in that case to water? With the temps and high humidity how frequently or infrequently would be safe to water for young starts, and should I give them more than crushed ice? Greg mentioned possibly every other day - I've been doing maybe 3 times a week with just the ice on the grit to melt over time for them. Should I maybe try increasing to every other day, even if raining, and keep with the ice? When I did it in the mornings past, it was always still coolish for a few hours after since it was pretty early on, but I'll stick to early evening now.

I'll work on getting some photos in the morning! Most of the affected ones shriveled up after I popped them out of the soil to 'dry out' in case that was the issue and then planted them in the deeper grit. The ones still standing so far I cut most of the rot out from and silly me didn't take photos beforehand. The one Viking has been out of the ground for a day and a half so far but hopefully I can get a photo of that one that will still show the issue.

Thank you so much for all the suggestions so far! Hopefully together we can get to the bottom of this so that I don't lose any more! This only started once the temps started getting into the mid and high 80s, and it only seems to so far be affecting semps I received around May - hence making me wonder if the high humidity + hotter temps had some stake in it.
www.ZenAndCoffee.com
[Last edited by ZenAndCoffee - Jun 20, 2017 9:33 PM (+)]
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Name: Wren
Wake Forest, NC (Piedmont) (Zone 7b)
Sempervivums
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ZenAndCoffee
Jun 20, 2017 9:42 PM CST
Of course now that I think about it, wooly mealies would fit all the signs and issues cropping up. I'm not seeing the white outside of one small area in the meristem where the rot is but I kind of don't want to take any chances. I'm almost wanting to go mix up some fresh systemic and treat just in case as now I'm paranoid lol! Though I really think it's something with moisture evaporating back into the grit around the base of the semps. Hopefully I can get some photos tomorrow to help illustrate this stuff.
www.ZenAndCoffee.com
[Last edited by ZenAndCoffee - Jun 20, 2017 9:44 PM (+)]
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Name: Greg Colucci
Seattle WA (Zone 8b)
Sempervivums Sedums Plant Lover: Loves 'em all! Cactus and Succulents Container Gardener Garden Ideas: Level 1
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gg5
Jun 20, 2017 10:22 PM CST
Good luck Wren, it does sound like you're trying everything!!
I know what that heat and humidity does to me and I'm not an alpine plant LOL
Keep us updated please... For me I noticed I was under watering my semps when it was getting really hot (Seattle hot, below 85 degrees) nodding

Name: Lynn
Dallas, OR (Zone 8b)
Charter ATP Member Garden Sages I helped plan and beta test the plant database. I helped beta test the Garden Planting Calendar I was one of the first 300 contributors to the plant database! Plant Database Moderator
Forum moderator I helped beta test the first seed swap Million Pollinator Garden Challenge Celebrating Gardening: 2015 Plant and/or Seed Trader Garden Ideas: Master Level
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valleylynn
Jun 20, 2017 10:46 PM CST

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Try a Q-tip dipped in alcohol for small areas of investation/rot.
Name: Wren
Wake Forest, NC (Piedmont) (Zone 7b)
Sempervivums
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ZenAndCoffee
Jun 20, 2017 11:05 PM CST
I was able to get some photos of the one Viking semp - I couldn't wait till morning to go check lol. It didn't have any of the white when I first uprooted it but now that it's been sitting out its got it all around the top base portion of the semp on the meristem. This one in particular bit the dust really quick and was a slightly larger rosette - about the width of a hockey puck. I had it maybe 3 days before this occurred and at the exact same time is when my Virgil Ford followed suit, both received from the same nursery at the same time. However, the other semps I got from there are doing just fine. Only those two varieties had this occur from that particular order.

On my other semps that had this issue, the white was only in a tiny area, but they were also much smaller starts. If I come across it again I'll be sure to take a photo this time.

Lynn - all the newest ones I just got from you are perfectly fine. They all went in the 1" grit top dressing though from the get go so maybe that's made a difference.

Since it's 1am here now I'll upload the photos in the morning as I'm pretty beat. I'm also holding off on systemic for now as I don't want to stress them unless I need to. Thinking about mealies makes my skin crawl lol, so I'm really hoping it's pretty much anything else.
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Name: Paul
southern California
Zone 8B/9A
Region: California Herbs
cahdg6891
Jun 21, 2017 1:07 AM CST
Wren, I think it may be your humidity that is doing it. I haven't ever really had rot issues with my own because it is so dry here. Our average humidity during hot days is around 5% (FIVE) Hilarious! but last year I brought a semp home from one of the Lowe's that we have here, where during the heat of the day they turn their overhead misters on and have giant fans that are hanging up all through the garden center turned on high. Feels like a jungle! The semp that I brought home from that Lowes showed the same symptoms you mentioned. The roots and everything were perfectly healthy looking, but then the bases of a few of the leaves turned and when I pulled them off, the crown/stem had a big chunk of rot in it despite the rest, roots and all, looking healthy. Having a thick mulch of rock/stone/grit also holds in moisture and prevents it from evaporating as quickly - I use a thick gravel mulch on cacti in terra cotta pots to keep enough moisture around long enough for them to get a drink before the heat and wind dry the pot out. So your east coast humidity and a thick mulch of grit holding in moisture might be the cause!
Name: Lynn
Dallas, OR (Zone 8b)
Charter ATP Member Garden Sages I helped plan and beta test the plant database. I helped beta test the Garden Planting Calendar I was one of the first 300 contributors to the plant database! Plant Database Moderator
Forum moderator I helped beta test the first seed swap Million Pollinator Garden Challenge Celebrating Gardening: 2015 Plant and/or Seed Trader Garden Ideas: Master Level
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valleylynn
Jun 21, 2017 9:08 AM CST

Moderator

Great explanation Paul. Thumbs up
Name: Tiffany Wreathfreshâ„¢
Puget Sound, WA (Zone 8b)
Sempervivums
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LivingWreaths
Jun 21, 2017 11:09 PM CST
Hi Wren,
Are you having weevil problems this year? weevils have decimated many of the plants in my yard in the last year, and not from the adults( in other words, no visible damage to the leaf structure). It's all about the babies! Weevil larvae are bad on their own as they will eat the root systems of Sempervivum & other plants from the inside out. even worse is the symbiotic relationship Weevil larvae have with a particular bacteria that will leave the root systems mushy. Bacteria soften the cell walls of the root system so that the larvae can easily eat their way through. Even with systemic treatment that will kill the larvae, the bacteria will be left behind and continue their mushy rot of the root system. I noticed that when the weather is warm and muggy, then cloudy, then rainy...repeat cycle... the weevils are bad in the bacteria are worse!
Name: Judy
Mid Atlantic Coastal Plain USA (Zone 7b)
Butterflies
MariposaMaid
Jun 22, 2017 9:58 AM CST
Interesting info Tiffany and sorry to hear of your semp damage and ongoing efforts to combat what is invisible to the naked eye.

Paul, Yes, the humdity levels and high heat do a number on semps and their gardener friends hereabouts.

In this area and I bet in Wren's when high humidity sets in along with heat there is little to no air flow and little difference between day and night temps (around 9-10 degrees) so no cool down. Water, from the skies or my rain barrel, whether applied at night or early am or via crushed ice, simply has no where to go!

Pots filled with Gritty Mix do not dry out like I would have expected a 'quick draining' medium to do......So, the knack of watering them and when and how much probably takes an algorithm far beyond me. D'Oh!

Name: Greg Colucci
Seattle WA (Zone 8b)
Sempervivums Sedums Plant Lover: Loves 'em all! Cactus and Succulents Container Gardener Garden Ideas: Level 1
Garden Art Birds Dog Lover Cat Lover Region: Pacific Northwest Hummingbirder
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gg5
Jun 22, 2017 4:02 PM CST
Those are good points Judy, and for me with my indoor succulents I've been learning to just water less when I water, so really just a sip once per week for them... I'm thinking semps in summer heat /humidity would be the same! I tip my hat to you.

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