How did it come back

[BigBilly]

So last August of last year I bought a Mandevilla vine from lowes last year and it came back this year. I'm super confused about how it came considering it was 5F last winter and I threw a pot full of mulch over it.  It's about 19" from a south-facing wall. but it's rated 10A? I'm wondering if anyone in 7B or colder experienced this and how can i make it come back again next year. 

[Silas_Sancona]

1 hour ago, BigBilly said:

So last August of last year I bought a Mandevilla vine from lowes last year and it came back this year. I'm super confused about how it came considering it was 5F last winter and I threw a pot full of mulch over it.  It's about 19" from a south-facing wall. but it's rated 10A? I'm wondering if anyone in 7B or colder experienced this and how can i make it come back again next year. 

Interesting, and pretty neat..  If i remember correctly,  these have tuber - like roots. If they ( and the root crown ) were protected enough under the pot of mulch you provided, the soil in that spot could have stayed above freezing at depth allowing the plant to re sprout later.. Imagine, it could have stayed drier ( if you'd kept the pot over the mulch you put on top of the plant ) too, which would also help the roots not freeze / suffer root rot.

Even 10 or 20" away from the foundation of your house, that too could be just close enough to it to give off enough heat through the coldest months to keep the soil where you planted it warm enough for the roots.

South facing exposure, esp against a south facing wall ( always the warmest spot in a landscape during the cooler months ) will also contribute to keeping the soil in that location warmer on cold days ..esp. if really cold days are far and few so the soil can't freeze to depth.

Who knows.. lol, maybe you're closer to 8A rather than in zone 7B then assumed too..

Some areas of S. AZ. and lower mountain slopes down there  can get into the teens a few times in the morning during cooler winters, yet certain plants -of tropical origin ( the family(s) they belong to ) survive. 



Regardless,  whatever worked, would repeat it this year. Might also scatter some SulPoMag around it now,  and again in late September or October ( as long as it is still warm enough for the plant to take up nutrients )  to boost the cold tolerance capacity for the roots ahead of the coming winter. 

Edited August 10, 2023 by Silas_Sancona
edit

[iko.]

As @Silas_Sancona said, these plants have tuberous roots which make them great drought resistant plants and occasionally, can survive light freezes and snow. I have seen this before but the plant needs to grow bigger during the warm season to withstand another cold period.  Photo attached is one I grew in London (UK) and was covered in snow for a few days. 

For the look of the leaves in your picture, I think yours is a Dipladenia. Mandevilla is similar but grows bigger leaves, flowers, and often, gets taller too. Roots of Mandevilla tend to be more delicate than Dipladenia. The name confusion Dipladenia-Mandevilla is as common as the Hippeastrum-Amaryllis and embraced by horticulture companies with no shame. 

Edited August 10, 2023 by iko.

[Silas_Sancona]

2 minutes ago, iko. said:

 

For the look of the leaves in your picture, I think yours is a Dipladenia. Mandevilla is similar but grows bigger leaves, flowers, and often, gets taller too. Roots of Mandevilla tend to be more delicate than Dipladenia too. The name confusion Dipladenia-Mandevilla is as common as the Hippeastrum-Amaryllis. 

 

This actually has changed.. Dipladenia  was a former name,  but has been lumped in with Mandevilla    ..Same thing occurred w/ Macrosiphionia / Telosiphonia,  a Genus of Mandevilla -relatives here in the U.S. Southwest, and adjacent Mexico.

From  the " Taxon " section on Inaturalist:

[iko.]

Thank you for the correction and info! A bit of a shame because the alleged Mandevilla and Dipladenia differences were helpful, to me at least.

For the OP, there is a type of Mandevilla that grows bigger leaves and flowers, and also gets taller... that one is not great with cold. The one you have looks like the type that handles drought and cool weather "better". Hope you can enjoy it for more seasons to come.

[Silas_Sancona]

3 minutes ago, iko. said:

Thank you for the correction and info! A bit of a shame because the alleged Mandevilla and Dipladenia differences were helpful, to me at least.

For the OP, there is a type of Mandevilla that grows bigger leaves and flowers, and also gets taller... that one is not great with cold. The one you have looks like the type that handles drought and cool weather "better". Hope you can enjoy it for more seasons to come.

I was surprised, ..kind of at least, lol..  when the swap occurred..  Esp. w/ the Genus that grows here.. Can see obvious similarity, but, the differences in foliage size / flowers kind of took some re adjusting to when the Genus was Mandevilla -ized. 

Agree regarding the bigger ones, definitely more cold / winter wet sensitive. There is a similar looking relative, Pentalinon,  that seems to be a little hardier than either the big flowered Mandevilla or Allamanda.   Was even able to grow it here ( in Shade ) for a few years until ..either the heat ..or getting too much water one winter   took it out.  Have seen it offered for sale in some big box stores, ..which was quite a surprise since it is ( ..or was, haha )  a rather obscure Florida native plant.

[BigBilly]

4 hours ago, Silas_Sancona said:

Interesting, and pretty neat..  If i remember correctly,  these have tuber - like roots. If they ( and the root crown ) were protected enough under the pot of mulch you provided, the soil in that spot could have stayed above freezing at depth allowing the plant to re sprout later.. Imagine, it could have stayed drier ( if you'd kept the pot over the mulch you put on top of the plant ) too, which would also help the roots not freeze / suffer root rot.

Even 10 or 20" away from the foundation of your house, that too could be just close enough to it to give off enough heat through the coldest months to keep the soil where you planted it warm enough for the roots.

South facing exposure, esp against a south facing wall ( always the warmest spot in a landscape during the cooler months ) will also contribute to keeping the soil in that location warmer on cold days ..esp. if really cold days are far and few so the soil can't freeze to depth.

Who knows.. lol, maybe you're closer to 8A rather than in zone 7B then assumed too..

Some areas of S. AZ. and lower mountain slopes down there  can get into the teens a few times in the morning during cooler winters, yet certain plants -of tropical origin ( the family(s) they belong to ) survive. 



Regardless,  whatever worked, would repeat it this year. Might also scatter some SulPoMag around it now,  and again in late September or October ( as long as it is still warm enough for the plant to take up nutrients )  to boost the cold tolerance capacity for the roots ahead of the coming winter. 

I mean my average minimum is 9F so I'm on the 8A border but I'm so confused about how it came back it was planted in August of 2022 then had the freeze in December so it had 2 months to really establish and the pot above it froze so it's really a wonder it came back. Not sure if the soil froze tho 

[Silas_Sancona]

2 minutes ago, BigBilly said:

Not sure if the soil froze tho 

That's your clue.. Generally speaking,  It takes prolonged, sub freezing temps to really " freeze ' the soil  ..deeper than say just a few inches..  The roots / tuberous roots  likely sat deep enough to avoid being frozen.. Add in the pile / pot of mulch you added above it ( Deep layer of Mulch on top of the soil = more warmth below the soil, thus, would take longer to freeze ),  and where you planted it  ..as long as those absolute  lows ( the single digit lows ) thru the winter were far and few,  and interspersed between warmer days, ..and  less  chilly nights, ..even if your lows through the winter were mainly in the high teens -20s at times, than yea, it could survive.

They're a fairly fast grower when it is warm, so it wouldn't take too long to develop a good enough root system to handle the winter ahead of it after planting..  Planted in August, yep, that would give it a few months before a freeze / hard frost to get itself settled in.

This winter will be a bigger test since it has had a full warm season to add on growth  ..to both the top,  and root system..  As mentioned, whatever you did, repeat it, cuz' it worked out exactly as you'd hoped.

[BigBilly]

11 minutes ago, Silas_Sancona said:

That's your clue.. Generally speaking,  It takes prolonged, sub freezing temps to really " freeze ' the soil  ..deeper than say just a few inches..  The roots / tuberous roots  likely sat deep enough to avoid being frozen.. Add in the pile / pot of mulch you added above it ( Deep layer of Mulch on top of the soil = more warmth below the soil, thus, would take longer to freeze ),  and where you planted it  ..as long as those absolute  lows ( the single digit lows ) thru the winter were far and few,  and interspersed between warmer days, ..and  less  chilly nights, ..even if your lows through the winter were mainly in the high teens -20s at times, than yea, it could survive.

They're a fairly fast grower when it is warm, so it wouldn't take too long to develop a good enough root system to handle the winter ahead of it after planting..  Planted in August, yep, that would give it a few months before a freeze / hard frost to get itself settled in.

This winter will be a bigger test since it has had a full warm season to add on growth  ..to both the top,  and root system..  As mentioned, whatever you did, repeat it, cuz' it worked out exactly as you'd hoped.

yeah it's a lot smaller than It was when i planted it, Really was supposed to be annual but here it is again 

[Silas_Sancona]

4 minutes ago, BigBilly said:

yeah it's a lot smaller than It was when i planted it, Really was supposed to be annual but here it is again 

All Mandevilla ( and stuff like Allamanda, other subtropicals like  Fire Bush, Shrimp Plants, and/or Bananas / Gingers ) are perennial,  though called an " annual " outside of where they are killed completely each year in winter..  Better term for such a plant would be " Die back Perennial / subtropical " ..or whatever.

Feed it now, ...w/ an emphasis on K ( Potassium ) and again in October,  and it should add some size, and be ready to take on winter again ( You'll loose the top growth again though, unless there are no / very light freezes there this year ).

[BigBilly]

Well, it's still here, Still thriving now it's just a race against time to see if it will flower or if a freeze will get it. 

[Silas_Sancona]

20 minutes ago, BigBilly said:

Well, it's still here, Still thriving now it's just a race against time to see if it will flower or if a freeze will get it. 

   Looks good...

You should get -at least- a few flowers before it gets cold enough that they get burned off.. ( Hopefully later rather than sooner )  While it may only extend the plant's growing season by weeks -rather than the whole winter season ahead- , If you haven't considered it yet, you might consider building some sort of portable, small cube over it that will provide extra protection from any early frost / freezes  / keep the ground around the roots from freezing sooner.  ..Kind of like what others in colder areas  here do to get hardier palms that might be a bit tender when younger through their first few winters.

[BigBilly]

Well it flowered after 5F , Think this rated a zone 9/10 

Edited October 13, 2023 by BigBilly

[BigBilly]

For anyone wondering It's returned for the 2nd year in a Row it's now been through 9F and 5F this year it was protected even less, and I'm starting to want to take cuttings and clone this plant !!!