Radermachera Summerscent

March 1, 2011

Radermachera sp. ‘Kunming’ ( ‘Summerscent’ misapplied by nursery industry) is as yet still an un-named species from Yunnan province in South China. This cultivar was identified in South East Asia, reportedly in Thailand. It has become popular in tropical gardens in South East Asia and has also been introduced to Australia, promoted in the nursery trade as Summerscent – this is however more of a marketing name rather than a true botanical name.

Radermachera Kunming

Family: Bignoniaceae
Other common names: Dwarf Tree Jasmine, Peep Thong

This plant has a dense, shrubby habit, typically attaining 2-3m height and spread. The glossy deep green foliage is pinnate in structure, similar to the Radermachera ‘China Doll’.

The large heads of flowers, which are light pink with a gold throat, fade to off-white as they age. They are pleasantly fragrant (reputedly even “fruity” according to the nose of some beholders). Flowers occur mostly in the summer months but can spot flower from spring through to autumn in the tropics.

It was recently introduced into Australia but has been slow to be embraced by gardeners, which is a shame. With great foliage, a long flowering period, scented blooms, handles full sun to part shade and the adaptability of this plant to a wide range of warm climates (tropical, subtropical and warm temperate) this plant should be on the WANT LIST for most gardeners. It is well suited to pruning as a hedge and screening plant, plus looks good as a pot plant specimen.

written by Paul Plant, Editor subTropical Gardening magazine.

updated: 27 October 2012

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{ 31 comments… read them below or add one }

Rosemary Srinivasan March 11, 2011 at 12:00 am

I’m new to gardening in Australia and joined the Townsville Garden Club to learn what plants grow well here. I bought Radermachera from Bunnings last year, and so I was really pleased to read your praise for this lovely plant. I have it as a pot plant on the deck and it is currently flowering.

Alex June 2, 2011 at 6:01 am

Radermachera ‘Summerscent’ – I am wondering if this is the small trees planted along parts of Waterworks Road, Ashgrove. They make a showy display when in flower but not all trees flower to the same extent as others. I must stop sometime when passing to have a smell and see if they are fragrant as it is described.

admin June 7, 2011 at 3:30 pm

Hi Alex, I rarely drive along that road so please keep us informed if this is the plant.

Ivy December 4, 2011 at 11:32 pm

I planted 7 of these trees along a bound fence last Feb and although they look healthy, green and flowering. The height hasn’t improved greatly. Can you advise?

admin December 5, 2011 at 2:24 am

Gardening can be a complex harmony of so many variables such as soil, climate, nutrients, soil microflora and soil microfauna… one imbalance can disrupt the entire system.
Gardening can also be a simple experience of planting, watering and caring for plants, then watching them grow, bloom and thrive.
However we all tend to have problems with some plants, yet other plants grow well.
If a plant looks healthy, is green and flowering, then what you are doing for plant husbandry is correct.
You can speed up growth with high nitrogen fertiliser (or animal manures) but that will be at the expense of flowers. It is a decision you need to make.

John Forlonge June 14, 2012 at 9:06 pm

My understanding is that this species is correctly named Radermachera yunnanensis and was described in 1979.

admin June 14, 2012 at 10:06 pm

Radermachera yunnanensis is definitely a recognised species however when checked with some botanists they could not verify if Summerscent was actually this specific species – both specimens need to be present to be evaluated.
R. yunnanensis – Trees ca. 16 m tall. Barks gray-black. Leaves 2(or 3)-pinnately compound, ca. 70 cm; lateral petiolules 1-5 mm, terminal one 1-2.5 cm; leaflets ovate, 4-9 X 2-5 cm, densely white glandular adaxially, base cuneate, oblique, margin entire, apex caudate-acuminate; lateral veins 5-7 on each side of midrib. Inflorescences cymose-paniculate. Calyx ca. 3 cm X 8 mm; teeth 5, long triangular, ca. 1.2 cm. Corolla white to pale yellow, 7-9 cm. Stamens 4, inserted nearly at base of corolla tube. Capsule gray-black when mature, long terete, subwoody, ca. 50 X 1-1.2 cm, densely white lenticellate, scabrous. Seeds ellipsoid, including wing 1.4-1.7 cm X 3-5 mm. Fl. Apr-May, fr. Aug-Nov. * Slopes, forests; 800-1100 m. Yunnan. http://www.efloras.org/florataxon.aspx?flora_id=2&taxon_id=200021439

Tracey House July 17, 2012 at 1:51 am

I have about 10 of these beautiful plants acting as a screen. I need to know at what time of the year do I need to hedge them? They are about 1-2 metres in height. Thank you

will March 27, 2013 at 2:29 am

we have just bought a radermachera summerscent read that it reaches 9 mtrs tall we were told it was a shrub plant can yopu tell me what summerscent grows to regards will

admin March 27, 2013 at 11:25 pm

HI, Where do you live? If in a colder climate, it will bearly reach 3-4m tall. If in the tropics, it may reach 7m. However, this plant is relatively new in cultivation and no mature specimens have been recorded in cultivation so height potential is not known.
This plant is best pruned into a bush as the label will suggest. If too high you will never see the flowers.
I hope this helps 🙂
ADMIN

Miriam May 5, 2013 at 9:23 pm

Hi,
I am really hoping someone can help me out with a question I have about this tree/bush. I have recently purchased one and have cut it so it forms a tree. I have been watering it daily and have it potted in a premium potting mix. I live in Darwin and am trying to grow it to plant when my new home is built in 6 months. Anyway, I went to water it today and it has white powdery fungus type balls growing on the leafs 🙁
What have I done wrong and how can I save my tree? Any advice old be hugely appreciated- thanks

admin May 5, 2013 at 11:21 pm

you have done nothing wrong… without an image I can only summise that it has mealy bugs.
Mealy bugs strike when the plant is stressed due to lack of water, poor nutrition or it is growing in the wrong conditions.
Give it some fertiliser, increase watering and be patient as it fixes itself.
If you are inpatient… use a pesticide.
Enjoy this plant 🙂

Craig September 20, 2013 at 7:27 pm

Hi,

I have a row of 5 Radamachera Summerscent that were planted approx. 18 months ago. They have all been planted, watered, fertilised in exactly the same way, but there is 1 plant that has shown next to no sign of growing – meanwhile, the plant next to it has more than doubled in size. The problem plant also exhibits brown edges around a lot of it’s leaves, it’s leaves tend to be more curled up than the plant next to it – and although looking far from dead, it just doesn’t look as dense or healthy compared to the others.

While I’d expect some randomness, there’s something wrong and I’m fairly certain it’s not due to under watering as they all get the same.

Obviously it’s difficult without a photo, but do you have any suggestions / ideas to try? Could it be pot bound? The second smallest out of the 5 is the one on the other side of this problem plant – could it be something with the soil around there?

Any advice old be great.
Thanks.

Alison Smith October 10, 2013 at 2:55 pm

I have 10 Radermachera Summerscents planted along my back fence they do have full sun and are about 50cms high. They were looking a lovely dark green for the first 4 months and have a little bit of flowering now some of them have yellow leaves. Last weekend I added a slow release fertiliser but there has not been any improvement. Appreciate any ideas?

admin October 10, 2013 at 6:24 pm

Depending on where you live, it is now dry in SEQld.
Dry conditions stress the plant plus also prevent nutrient uptake.
It may takes week for fertilisers to become available to plants unless you applied a liquid solution directly to the leaves.

admin October 10, 2013 at 6:30 pm

HI
Best option is to dig the sick plant out and look at the roots (for curling and binding) and look at the hole it was placed into (for compaction, chemical toxicity and pollution).
Fixing the roots may be as simple as cutting them fresh and repotting into a POT to allow the plant to recoup – then plant out in a new months.
If soil is the problem, you may need to get a professional soil analysis done – this may cost a lot of money but its is well spent if the soil is contaminated.
You can also do quick-fix to the soil (but will not fix contamination) by adding fresh compost and making sure hole is big enough to plant to grow into. Check the water penetration capacity of the soil by filling to hole with water and watching it soak into the surrounding soil – if it does not soak in you have a problem; if is soaks in TOO FAST you also have a problem.

ADMIN

Dean Whitby February 26, 2014 at 9:16 pm

Another grower labels this Radermachera ‘Fragrant Empress’, but appear to me to be identical to ‘Summerscent’ (just different label names). Whatever you call it, best new screening/hedging plant I’ve seen – may finally put Murraya and Golden Duranta out of business!

Sue March 21, 2016 at 4:44 pm

We are thinking of purchasing Radermachera Summerscent to make a hedge. We live in WA and during summer experience very strong winds constantly, with temperature average about 35 deg. Winter is mild. Will this plant do well in these conditions?. Also is the plant a bit temperamental?

Jan April 12, 2016 at 10:50 pm

We grow these in Port Hedland with summer temps between 39 c to 47c strong winds they survive well . Hardy & a nice perfume flower . Ideal as a shrub & hedging.

Jan April 12, 2016 at 10:54 pm

The leaves do go yellow in extreme summer temps but back to green when temps drop .

Ty September 8, 2016 at 12:23 am

Hi. I live in Brisbane and recently bought one of these from Bunnings. The label said height to 3 mtrs. I hope mine does not go more than that.
Does anybody here have any idea about the root system? Is it invasive? I live in a medium size suburban block (approx 690 sq m).
Thanks for any info.

Ian October 13, 2016 at 6:40 pm

We planted our 5 trees at a height of about 70cm 18 months ago, they are now approx. 2 metres and look extremely healthy with no damage or disease. I wish to prune them as individual trees, not a hedge. Would you please advise best time to prune? We live near Caloundra on the Sunshine Coast.

admin October 13, 2016 at 7:06 pm

Hi Dean
Radermachera ‘Fragrant Empress’ and ‘Summerscent’ seem to the same plant
ADMIN

admin October 13, 2016 at 7:09 pm

Hi Sue from WA
this plant is incredibly adaptable.
I have it growing at the base of a mature gum tree and while others look water stressed, this plant is still green. I’m not saying its indestructible… its just awesomely tough!
In the sandy soils of WA, make sure you have added organic matter to help with water retention in the soil
ADMIN

admin October 13, 2016 at 7:12 pm

Hi Ty, Brisbane
The specimen at Mt Coot-tha Botanic Gardens is about 2m tall. I suspect it will grow 3m. It is basically a large shrub that can be pruned down but I think it looks best if around 2m tall.
As for roots, there have not been around long enough to grow to mature dimensions so lack of information about root issues – sorry.
Hopefully if someone has had them for 10 years, we will find out more.
ADMIN

admin October 13, 2016 at 7:15 pm

hi Ian, Caloundra.
Prune these plants during the warmer months.
If you are seeking to create a tree-like structure, you will need to remove all the lower branches to create a ‘trunk’. Hopefully the early nursery cultivation of the plant will have a single trunk at the base, not a multitrunk structure.
All the best 🙂
ADMIN

Lesley October 20, 2016 at 5:25 pm

Hi, mySummerscents have been in the ground in Perth for about 18 months and have been thriving well. I have recently noticed that some of the leaves are a coppery colour although they still look healthy. Is this a concern do you think?

Heather May 31, 2017 at 12:47 am

Hi, I’d like to talk to Ian. I’ve just moved to Cooroy and am looking to establish my small garden using tropical plants. The garden gets heaps of sun (so apparently the smaller palms are out of the question and I don’t want golden canes) so the Radermachera Summerscents sound perfect. I’m not technologically savvy so don’t guarantee I could find this website again. Would ‘admin’ pass on my msge and email address to Ian plse?
thank you, Heather.

admin May 31, 2017 at 2:52 am

Plenty of excellent consultants in the Cooroy/Noosa region who know the area and growing conditions.
Contact paulp@plant.id.au – editor of subTropical Gardening magazine.

Andre June 26, 2017 at 10:18 pm

90% sure there is a 4-5m tall one in Mt Cootha

admin July 30, 2017 at 1:10 am

Heather. I am in Cooroy/Lake Macdonald and do garden consultations along with plant sourcing … Contact me on paulplanthort@gmail.com.au
FYI.. Noosa Botanic Garden Plant Fair is on Sunday 3rd Sept. Put that in your Diary 🙂

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