Aloes - hard to grow in hot climates (or not?)

[Gee.S]

Others whose fate is yet unknown: 'Candy Corn', capitata v. gneissicola, congolensis, elgonica, erythrophylla, glauca, globuligemma, ikiorum, 'Kelly's Blue', mawii, peckii, rupestris, 'Scarlet Rockets', scobinifolia

So how did the A. glauca fare?

[Melt in the Sun]

Died! As did elgonica and erythrophylla (doing well but eaten by rodents) and 'Kelly's Blue'. The others are still with me. Some are doing great like globuligemma (flowers froze though), ikiorum, and scobinifolia. The others are hanging on but I don't think they're in it for the long haul. I have seen glauca at the DBG (i think) so may try it again sometime.

[mcvansoest]

The Aloes at the DBG are all in pretty heavy shade for large parts of the day. Even their Hercules is under one of the large shade structures that is devoted largely to Aloes and related plants and Euphorbias.

Melt, the Aloes I got from you this spring are all looking like they have developed some roots, some are further along than others, so those are looking good, but for now they are obviously under my shade structure.

I am testing two 'new' ones in full morning sun: Aloe cameroni and something that came labeled as Aloe 'Apache' (I will have to check that as I got it with two other named hybrids/cultivars and I could be mixing them up, I know it is not Aloe 'Swordfish', but it could be the other of which I will have to retrieve the name from the pot it was in). They are out of the sun by 1 PM at the latest. The cameroni essentially is growing all new leaves that look pretty much adjusted to the sun, but the old leaves are burning away. I kept another cameroni on my front porch which gets heat, but in the summer almost no direct sunlight (sun angle is too high), it colored up for a while but is now fully green and quite happy. I also got Aloe 'Swordfish' and a third hybrid/cultivar of which I do not remember the name at the moment there.
I have aloe camperi and vaombe in full sun for most of the day in my back yard. I also have what I got as vacilans and an offset from trichosantha in nominally full sun there, though I have some persistent Bermuda grass that keeps coming back providing those with some shade - the previous owners of the house just dumped gravel over the grassy areas without doing any kind of removal. So I have random areas where I get the grass coming back... such a pain... Those are both hanging in there though the main clump of trichosantha I have is in mostly shade until late afternoon.

My main sense is to keep most Aloes out of the all day full sun areas until I run out of space along the east side of the house.

[Smokestack Lightning]

Hello All. First post here. I recently moved to Phoenix from Oakland, CA. Needless to say it has been an adjustment in more ways than one. Many plants came for the journey, one of my favorites being a 10+ year old Kumara (Aloe) plicatilis. The Bay Area climate suited it well and I never had any issues. Enter Phoenix summer. I moved it to a shady area after showing some signs of sunburn earlier in the season. Over the last few weeks it started wilting significantly. Some blackening of the tips. It's in a 20 gallon (? - big) pot. I backed off on watering, but equated the wilt with dehydration from the heat - so I brought it inside. It's still looking pretty wilted and the new spurts of growth aren't fully plump. Attached is a picture (with cattle dog photobomb). I think it'll do fine once things cool off, but I'm looking for advice on how to limp it through the summer.

1. Back off on watering despite the wilt?
2. Keep it inside to avoid 90 degree night temps?
3. It gets lots of indirect light inside, but is the lack of fuller sun hurting it, too?

Thanks for any words of wisdom.

[Spination]

So, I'm in Sonoma a bit north of where you were but significantly hotter than Oakland which enjoys mitigation thanks to the bay influence. I have several of these. A have a large one root-bound in a 20 gal pot that gets AM sun - I water that every single day. I have another in a 5 gal that sits out in full all day sun, and I also water that every day. The hotter the climate, the more you need to water it. Smaller ones I have in partial shade and don't have to water them as often because the pots don't dry out that fast. It all comes down to the temperature, sun exposure, how root-bound, pot size - basically the combination of factors that determine how quickly the soil dries out. If like with my big plant the water is all absorbed in one day thanks to an extensive root system - I have to water it every day or tips will yellow, brown. The one I have fully exposed to the full effect of heat here I also have to water every day because that's how fast that pot dries out. The ones I have in partial shade don't dry out so fast, so those don't require as frequent watering.

I would give your plant a good soak and even add B1 supplement (used for transplant shock, and promoting roots, etc). I've attached an image of the product I use. That should help perk it back up.

B1.jpg (119.55 KiB) Viewed 7559 times

[mcvansoest]

Welcome both to Arizona and the site!

Every few years some of the Big Box stores will have some for sale here. I bit one year... Needless to say it did not make it through one summer. I did not bring it inside, but saw the same blackening going on on the leaves.

The fact that it did so well in the Bay Area should probably already be a sign that this is not really an outside plant here in the summer. Many Aloes that have more xeric/desert suited pedigrees than the plicatilis suffer greatly or outright croak here in summer.

If it was outside through most of June and the start of July I worry that the heat both at night and during the day compromised the roots (I equate the blackening of the leaves with signs of severe stress - which given that it has not ever experienced anything like this is not a strange reaction) and crazy low humidity here compared to it previous growing conditions also will not have helped any with the wilting. Since bringing it inside has not really helped with the wilting, issues with the roots are a concern. The fact that it still had some new growth could be an indicator that some roots are still OK, or that the plant is just using stored energy to grow.

I am not sure I should suggest bare rooting the plant to see what is going on right now, because if the roots are actually OK, or recovering, bare rooting them may make the problem worse, but definitely keep a very close eye on the base of the trunk for any signs of rot, due to a color change or change in overall feel - go squeeze the base of the trunk it should not be squishy. Not sure if you had a sense of how well the plant was rooted in its pot, if you do, then determining if there has been a distinct change by gently tugging on the plant or shaking the pot a bit can maybe help you get a sense of any changes - if the plant has become a lot more loose I think that may imply a root issue.
From the picture the trunk looks pretty good and the leaves definitely are still in reasonable shape - but I had an Aloe dichotoma look great up until the day it dropped all its leaves when the rot making it slowly up inside its trunk reached the crown - bad timing on a transplant.

As to watering, the problem is if the roots are compromised, watering the plant may not actually help, but could just make the issue worse. However without water the wilting is unlikely to get resolved.

How often were you watering it when the plant was outside? At this point a root issue could have resulted both from over watering and under watering. In case of under watering keeping it inside while watering it sparingly when the soil in the pot is almost completely dry at depth might entice the plant to regrow some roots and be OK. Overwatering would have resulted in rot which will not be addressed by being patient with the plant.

The problem is that if you bare root it now, you will probably have to let it sit bare root for at least a couple of days if the roots are fine or just desiccated and probably quite a few days longer if there is an issue with the roots (to cut rotting roots away and let the damage heal over), if you have an easy spot to do that inside then you could do that if you were so inclined, but you would definitely not want to let it sit bare root outside.

I guess if this was my plant and I could convince myself somehow that it was not a root rot problem, I would try and keep it alive till we get to some more benign day time temperatures and night time lows are below 80 again. At that point, if the plant was still pretty much in the same condition, I would probably bite the bullet and bare root it to see what is up. Until then, I would water minimally only if I know the pot was pretty much completely dry. Growing roots back takes time especially for a big old plant like this so, it could be possible that it was root die back due to being too dry and over the coming weeks you might see some signs of improvement. It is a tough decision though, because if it is rot you probably want to deal with it sooner rather than later.

If it survives, for future summers you will want to bring it in before it gets really hot, not just at night but also during the day, so maybe bring it in some time in late May, and maybe not bring it out until late September. You will probably want to get a grow light for the plant if it is going to spent a lot of time inside to supplement whatever regular light it is getting, and a small humidifier as well, while humidity tends to not be as low inside houses it still is pretty low compared to the Bay Area.


Now a completely different train of thought based on some of the stuff Spination just recently posted on one of the Aloe polyphylla threads here regarding why so many people have issues growing Aloe polyphylla - they treat it too much like a regular Aloe and therefore generally under water at which point the plant has an impossible time dealing with non ideal conditions. I do not know enough about plicatilis to know if its regular growing conditions in habitat are distinctly different from most other aloes to warrant treating it differently, but it might warrant some research. Though I would probably still think that Aloe polyphylla would not work here just because the summers are just so brutal, and I think the same is true for plicatilis (and many other aloes), his points have given me the itch to try and see what happens if you do not treat it like a desert adapted plant and plop it in the ground somewhere in a shady spot and water the c$#p out of it every day. I suspect the sustained period of >80F night time lows will probably still do the plant in, but...

Anyway, good luck and sorry I could not give a more definite answer - like I wrote early I tried this plant and miserably failed (as I have with quite a number of aloes, though I have succeeded with quite a number of them as well, so it is definitely a question of getting the right ones). Another place you might go for advice is the CACSS (Central AZ Cactus and Succulent Society - https://centralarizonacactus.org/" onclick="window.open(this.href);return false; ) - they list plant experts on their website and I am sure there has to be someone who has Aloe expertise on there.

[mcvansoest]

Cross posting...

I guess another argument regarding the potential of root rot: following Spination's advice is probably not going to make it any worse if there is root rot and is bound to make it better if there isn't.

Though I would caution strongly against equating Sonoma summer heat with Phoenix heat island summer heat, especially at night. The only night in the last 6-8 weeks we have been below 80F has when we got some monsoon rain last Friday, and we went all the way down to... 78F... That is probably what your plant would see for a summer high most of the time in Oakland.

[Spination]

I didn't go through the whole last post, but I noted an erroneous assumption early on about the blackening of the leaves. Plicatilis does this on the LOWEST leaves and that is 100% normal, it is a part of the leaf retirement process. Most other aloes the lowest leaves as they are retired turn brown as they desiccate, not so with plicatilis which turn completely black, and when the black has reached the trunk/branch and the leaves are completely dry, they can then be easily pulled off. As my plant grows and hence retires oldest leaves, I am regularly pulling them off. Here is a pic of my big plant I just took minutes ago to illustrate this blackening leaf phenomenon.
I have 8 or 9 of these plants - they all do the same thing so it's not something abnormal going on with only one of mine. The faster they grow, the faster they retire oldest leaves, the more you will see these black leaves at the bottom of each fan.

2020 08 01 Kumara plicatilis leaves blackening in retirement.jpg (126.66 KiB) Viewed 7556 times

[mcvansoest]

I believe you, and maybe what is happening to SL's plant is just simple leaf die back, but given that leaf die back can also be a response to stress, which I think we can agree the plant has been under, it is not necessarily an erroneous assumption.

Also if you did read all the way to the end of my post you would actually see that I refer to your post on Aloe polyphylla watering...

[Smokestack Lightning]

Wow. Many thanks for quick and thorough responses!

I agree that there are several factors at play here.

1. Watering. Phoenix summers are beasts. This is my third one, but the first for my wilting friend. Despite the rough similarities in humidity and peak daytime heat to other areas, the relentless nighttime heat sets Phoenix apart. As McVansoest mentioned, it never really gets cooler than 85-90. Where other locations have a greater diurnal temperature swing, Phoenix just stays HOT. I bet this influenced the wilting. I was watering the guy with a thorough soak once per week, which was sufficient through late June...or maybe not since it pooped out.

2. Blackening Leaves/Root & Soil Conditions. Absolutely, Spination: the lower leaves blacken and fall off as new growth progresses. I've observed this characteristic of plicatilis over the years, as well. Currently, approx. 30-40% of the leaves have blackened tips (~1-2"). I've read that this is a sign of root rot, but considering the potential dehydration (exhibited by wilting) and different characteristics of this species relative to other aloes; I wonder if it's just an extreme sign of the heat shock. The trunk and branches feel rigid/sturdy and don't exhibit any signs of softness or rotting. The plant is probably very root bound - it has been in this pot for years, but it grew like a weed in California so I was okay with pot size being a limiting factor to overall growth. Bare rooting is new to me (and intimidating!). I'll probably hold off for now, watch it for a few weeks, and consider it if there are any advancing signs of root rot (more blackening on non-basal leaves or softening of trunk or branches).

3. B1! I'll try some fertilizer to see if it'll help.

Game Plan:

Keep inside. Conservatively water ensuring dry roots between watering. Fertilize. Consider bare rooting if progressive decay.

Propagation Question: What's the best way to propagate off the big one? Cut a branch, let it scab, rooting compound, and plant? Is it a bad idea to try to propagate from a stressed plant (i.e. will the start be too stressed to take off?)

P.S. Spination, nice seeing a pic of your happy K. plicatilis!

[mcvansoest]

If your plant is root bound that is almost certainly another factor with regards to the heat and hydration. In my experience root bound plants that are kept outside tend to start an usually slow, some times multiple summers long, steady decline if it is not remediated. I have seen this in many Agaves, a number of Aloes, and some cacti.

Root bound plants also need a lot more water than plants with plenty of soil, given that there is not much soil around to hold any water and the roots are even more prone to overheating both during the day and night. So hopefully another indication it is not root rot. However, I have seen Aloes literally turn to mush overnight like most succulents do here when it gets hot here, so be on the lookout for changes in the base of the trunk.

Not sure (actually I am pretty sure it won't be) this will ever be an outside in the summer plant here, would be great if it could be, but there are enough people out here who have invested years and years in growing and testing Aloes that I would have expected someone to have figured it out if it could be done.

[raimeiken]

It's been quite a tough summer here in AZ. Lost several aloes from those high overnight temps. Even my older established Rupestris in full sun rotted. The ones that made it are ones that are planted in shady spots like my Pseudorubroviolacea, Thraskii, Peglerae, Spectabilis, Secundiflora, Spicata, Sabaea, Helenea, Fire Ranch, Divaricata, Castanea, Erik the red, and Chaubadii.

Ones I have in full sun that made it are my big marlothii, a small Hereroensis, 1 out of 4 vaombe, 1 out of 2 big secundiflora, and 2 small rupestris.

The Aloe tongaensis I planted in my courtyard that gets pretty decent afternoon shade almost didn't make it. The last stretch of the heatwave rotted the two tops of it, so I had to behead it.

Here's just a few that I lost off the top of my head:
Glauca (shaded, rotted end of August)
Vanbalenii (shaded, lasted until the last week of heatwave)
Globuligemma (shaded, first one to rot in the beginning of summer)
small petricola (full sun)
3 years in ground Speciosa (full sun, rotted around middle of August)
Claviflora (full sun)
Arborescens (semi shaded)
Aculeata (Full sun, rotted around middle of August)
3 years in ground Ferox (full sun, rotted around middle of August)
Cameronii (full sun)
Alooides (full shade, almost made it but rotted end of August)

I think most of these would have made it if it weren't for the record setting stretches of 110f+ days and overnight highs. I'm not sure if I'll attempt at some of these varieties again if summers going forward will be like this again. Either that or I'll maybe try some of these again but in shadier spots this time around.

[Melt in the Sun]

Thanks for your input! I haven't lost too much this year, mostly because I barely try anymore:
- peckii in ground a few years, afternoon shade
- rupestris, second year in ground, afternoon shade
- aculeata, fourth or fifth year in full sun
- capitata v. gneissicola, tried to transplant out of sun and killed it
I think there are more but I'm out of town right now so am going off he top of my head.

I do still have:
- globuligemma, 3rd or 4th year full sun, well-watered
- 10-year-old multiheaded ferox but it looks pretty bad this year
- 4' dichotoma in full sun
- 3-year-old tongaensis in mostly shade, looked good until a few weeks ago. Core is OK so far but leaves are iffy
- microstigma in half sun
- 2x claviflora in full sun
- hereroensis in full sun
- gariepensis in full sun
- 2x karasbergensis in full sun
- peglarae half sun
- ikiorum in mostly shade
- scobinifolia in full sun
- 2x tomentosa in full sun
- verdoorniae in full sun
- pseudorubroviolacea in mostly shade
- hemmingii in mostly shade
- longistyla in half sun
- a bunch of potted shaded things: gerstneri, 'Candy Corn', cremnophila, 'Spiney', jucunda, mawii, probably some others

That's a surprisingly big list of survivors...hadn't really thought about it in a while. I still would like to try dhufarensis and shielae since they grow in full sun at the DBG in Phoenix. For me, gariepensis, hereroensis, and claviflora are still the full-sun winners.

[mcvansoest]

Yep it was tough. My Aloe losses were relatively minor but that is mostly because I lost a whole bunch last year after my late April plant move.

I have dubbed what happens after high overnight Ts with some water involved the 'sudden turn to mush' syndrome. I lost a few potted spotted Aloes interestingly limited to the larger generation in larger ~1 gallon pots, all the ones that I have been lazy in potting up and are crowding 4" pots made it (though with lots of dried up leaves).

I lost the Aloe cameronii I put in the ground, the one I kept in the pot has made it so far but I was late in realizing that the sun is already low enough that it reaches it and it got some heavy sun burn going on. It has been moved to fuller shade. I lost what I got as Aloe 'Apache' and a nice variegated Aloe xspinosissima which were in the ground.
My Aloe vaombe is on live support as is Aloe camperi, which is mostly due to it still being a barely established cutting from a big clump that was capable of taking full sun at the old house.

Oh, yes, I also probably lost the Aloe barnacle I just got from ISI this summer. There is a chance it revives as it was not rot that did it, but probably too little water.

When it gets hot at night I get really worried about watering specifically my aloes, but this year I also had a few Agaves do the 'sudden turn to mush' thing, with a nice Agave montana being the most irritating loss.

My newly acquired Aloe 'Hercules' looks like it will make it, but it got sunburnt leaves despite mostly being covered in shade cloth.

What I did notice is that plants with thicker more succulent leaves performed way better than those with thinner leaves. I also have quite a few now on the north side of my house which only receive early morning and late afternoon sun. The only loss from there was the variegated Aloe x spinosissima which has the thinner leaves.

Other things that performed surprisingly well were the bumpy miniature Aloes and some of their slightly larger siblings like Aloe Delta Lights, Aloe Swordfish, and Aloe Coral Fire. Some of these took a surprising amount (but certainly not full day) sun.

However, this summer was just exceedingly tough. We obviously broke the record of 110+ days by a lot and are second on the list of 100+ days - but we might still break that. Add the general lack of rain (I got about 1.2" since mid May) and it made for the perfect oven situation. I have well established Agaves looking like they were on fire at some point. Also, lots of trees in the neighborhood are looking really bad as well.

But to end on a more positive note here is Aloe 'Spiney' looking pretty happy about 3-4 weeks ago (it still is looking happy):

IMG_1576.jpg (175.15 KiB) Viewed 7329 times

[raimeiken]

Thanks for your input! I haven't lost too much this year, mostly because I barely try anymore:
- peckii in ground a few years, afternoon shade
- rupestris, second year in ground, afternoon shade
- aculeata, fourth or fifth year in full sun
- capitata v. gneissicola, tried to transplant out of sun and killed it
I think there are more but I'm out of town right now so am going off he top of my head.

I do still have:
- globuligemma, 3rd or 4th year full sun, well-watered
- 10-year-old multiheaded ferox but it looks pretty bad this year
- 4' dichotoma in full sun
- 3-year-old tongaensis in mostly shade, looked good until a few weeks ago. Core is OK so far but leaves are iffy
- microstigma in half sun
- 2x claviflora in full sun
- hereroensis in full sun
- gariepensis in full sun
- 2x karasbergensis in full sun
- peglarae half sun
- ikiorum in mostly shade
- scobinifolia in full sun
- 2x tomentosa in full sun
- verdoorniae in full sun
- pseudorubroviolacea in mostly shade
- hemmingii in mostly shade
- longistyla in half sun
- a bunch of potted shaded things: gerstneri, 'Candy Corn', cremnophila, 'Spiney', jucunda, mawii, probably some others

That's a surprisingly big list of survivors...hadn't really thought about it in a while. I still would like to try dhufarensis and shielae since they grow in full sun at the DBG in Phoenix. For me, gariepensis, hereroensis, and claviflora are still the full-sun winners.

I need to retry Claviflora again. The two small ones I had hung around till the end of the heat wave and melted.

I also wanna try karasbergensis and Tomentosa. Where did you get yours from?

[mcvansoest]

I grow both too. I got my tomentosas from the Boyce Thompson Arboretum a few years back.

Aloe karasbergensis I got from the Desert Botanical Garden plant sale.

Tomentosas in mostly shade have been very happy. Karasbergensis had a really hard time just after I got it, in mostly shade. I managed to keep an offset alive and it has been in a pot since then. It scraped through this summer, but looks like it is putting on some new growth since it got a little more humid and since I put it in some more shade.

Aridlands has Aloe karasbergensis for sale.
A member here had Aloe tomentosa seedlings as recently as a couple of months ago (Xanthoria).

[Melt in the Sun]

I got both of those species from Plants for the Southwest, a local nursery here in Tucson. It was probably 8 years ago for karasbergensis and 5 for tomentosa...not sure if they are growing many aloes these days but it might be worth an inquiry.
https://plantsforthesouthwest.com/" onclick="window.open(this.href);return false;

[raimeiken]

I grow both too. I got my tomentosas from the Boyce Thompson Arboretum a few years back.

Aloe karasbergensis I got from the Desert Botanical Garden plant sale.

Tomentosas in mostly shade have been very happy. Karasbergensis had a really hard time just after I got it, in mostly shade. I managed to keep an offset alive and it has been in a pot since then. It scraped through this summer, but looks like it is putting on some new growth since it got a little more humid and since I put it in some more shade.

Aridlands has Aloe karasbergensis for sale.
A member here had Aloe tomentosa seedlings as recently as a couple of months ago (Xanthoria).

Went by summerwinds at Tatum location and got a Karasbergensis today. 3gal size for $70.
I also picked up a Rubroviolacea 3gal size for $50.

That location always have lots of cool aloes.
They also have Excelsa, which looked pretty best up from the sun. Has anyone tried growing one here yet?

Also, does Xanthoria have a website that he sells from or do I just PM him about the tomentosa?

[tazmaniac]

I haven't read all the posts for this thread, but one chap indicated that a. barberae (bainesii) was hard to grow in the Phoenix area. I must be lucky. I bought a small one from Huntington Garden in 2003. It has been in the ground since 2005 -loose soil, afternoon shade, spare water in the hot summer months. It is now about 15 feet tall and is doing fine. It bloomed for the first time early this year. I am sure my hubris will now lead to its demise.

[Melt in the Sun]

Hey that sounds amazing! Can you share a photo?

[tazmaniac]

Melt in the sun -
Here is photo of the a.bainesii/barberae in the backyard. It is in very loose soil and gets shade or filtered sun in the heat of the summer. To the right of it is a. vaombe. To the left is a small a. rupestris.

[tazmaniac]

Haven't been on this site for a while. Just noticed my photo didn't attach in the previous post, so here it is. The tall one is a. bainesii (20 yrs), the one on the right is a. vaombe (20 yrs), and the short one on the left is a. rupestris (5 yrs), all living happily in the Phoenix area.

[mcvansoest]

I suspect your photos posted sideways...

[mcvansoest]

Fixed it before it got axed again - easiest fix is to not try and post portrait photos - just use landscape ones - or quickly hit edit on the photo and rotate it 360 degrees and save that which usually fixes it. This photo was indeed 90 degrees off when I downloaded it.

As to the plants: Nice! I have a tiny one from the huntington as well - have had it for 2 years now. All I can say it is not dead yet but compared to say Aloe sabaeae it has been super slow. My rupestris flowered successfully for the first time this year. They are the north edge of my north facing patio... will be interesting to see what happens when they grow tall enough to outgrow their shade... bad things I expect.

[tazmaniac]

Ugh! Sorry about that. Still getting the hang of it.