I bought this plumbago plant that i wanna use in my perennial border but i dont know where to put it exactly (front or back) and how far from the rest of the plants. I read that it can get up to 10 feet high and wide in its natural surroundings where there's no danger of frost but since my area gets frost, it will never reach that full size mentioned but exactly how big will it get everything before frost comes and kills it to the ground? If anyone has any experience of growing this beautiful speciman, please let me know as far as spacing is concerned.enter image description here

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    I'm guessing you don't know the varietal name of your plant - can you add a photo of it please?
    – Bamboo
    Commented Dec 9, 2019 at 11:51
  • Yes of course. It's the most common one by the way. The one that produces sky blue flowers. Or atleast that's what I've read. Commented Dec 9, 2019 at 15:16

2 Answers 2


Plumbago can tolerate a lot of sun and heat so if its in shade, it might not get as big as otherwise. I think that in this area (central TX) they are treated like a "cut and come again" perennial which means they usually freeze to the ground and even if they don't freeze all the way, they will be looking messy so you cut them back to a foot or two. I lost the plumbago that I had but have several other plants in this category including some TX natives. If you have a very mild year with only light to no frosts, then the plant will be much bigger the next year than you are used to.

Exactly how big they will get in your area during an average year will depend on soil, rainfall, etc. If you include your location in a question, people can give you a better answer. Also, another good place to ask is at a locally owned plant nursery.

  • I completely understand the whole light frost and severe frost concept which makes this whole thing so damn tricky. I don't wanna leave too much barren space but also don't want the plumbago to start taking over other plants. The site where i wanna plant it gets full sun. I have an arid climate. I dont know how to put that in hardiness zone terms. Stuff that grows here includes pomegranates, apples, peaches, mulberries, figs, grapes, cherries. Commented Dec 9, 2019 at 15:16

From the image you supplied, it looks like Plumbago auriculata, which can get up to 4m in height, in theory. Its spread is 1-1.5 metres, but although it can reach up to 4m in height, it will only do that if it is supported, the way you would support a climbing plant, otherwise it's more of a scrambler, growing over itself in a mound, or over other nearby plants.

How well it will do in your climate is literally down to how cold it gets - it will tolerate down to 1deg.C, but prefers temperatures above 5degC - it will be killed by zero degrees or any heavy frost with that sort of temperature. Frost occurs at around 5degC unless the weather is windy, but that will only be a light frost, so if your thermometer outdoors drops below 1degC for a few nights, it may kill it rather than just cause a bit of damage.

If your low temperatures are never below 1degC, then take into account its spread before choosing its spot, which should be sheltered - if you're going to support its growth, then placing it nearer the back seems optimal. Pruning of any dead parts and for reshaping can be done in spring. Further info here, though it's a UK link https://www.rhs.org.uk/plants/13333/Plumbago-auriculata/Details In the UK, this plant is not hardy at all.

  • Thanks for the info. I visited my local nursery and they've told me that it's gonna die back in our cold winters here but will most likely sprout back again come spring. However, we've already had temperatures dip below 0c• and the plant is fine. Not flowering but otherwise still green. I have it on the roof of my house next to an east facing wall. I guess the wall is sheltering it from the winter winds but out in the open, which is what i plan to do, it would probably never reach it's full mature size as stated in the article cause frost will most likely kill it every year. Commented Dec 12, 2019 at 15:13
  • So how big will it get per season? 3 feet may be? Also, how do people usually grow it? With or without support since it is technically a shrub.. Commented Dec 12, 2019 at 15:17
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    Any estimate as to size achieved in a season is only a guestimate at best, depends on the weather, but allow 3-4 feet. Try growing it without support to start with, see how well it does - if it becomes a tangled heap, you can always prune it back and start again one spring, if winter doesn't kill it to the ground. Are you keeping it in a pot?
    – Bamboo
    Commented Dec 12, 2019 at 15:33
  • This has been very helpful. I think I've got it figured out now. I'll give it 4 ft of space as per your judgement. And yes, it's in a pot but I'll be putting it in the ground as soon as spring comes. Cannot wait to have a touch of blue in the landscape since it's so rare in the plant kingdom. Commented Dec 13, 2019 at 17:36

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