A trip to Tregrehan to study Hydrangeas

Back to 26th July 2020.

On the 26th July 2020 we took a trip to Tregrehan to study Hydrangeas, however of course we were a bit side-tracked with other things, as you will see below.

A most confusing subject with much renaming and juggling of classifications. Quite how you decide what is aspera ssp. sargentiana and aspera ssp. Villosa Group remains a mystery which was not revealed during our tour.

The late flowering Hydrangea aspera ssp. robusta ‘Titania’.

Hydrangea aspera ssp. robusta ‘Titania’
Hydrangea aspera ssp. robusta ‘Titania’
Hydrangea aspera ssp. robusta ‘Titania’
Hydrangea aspera ssp. robusta ‘Titania’
Hydrangea aspera ssp. robusta ‘Titania’
Hydrangea aspera ssp. robusta ‘Titania’

Hydrangea ‘Stunner’

Hydrangea ‘Stunner’
Hydrangea ‘Stunner’
Hydrangea ‘Stunner’
Hydrangea ‘Stunner’
Hydrangea ‘Stunner’
Hydrangea ‘Stunner’

Hydrangea chinensis aff. (Wilson collection).

Hydrangea chinensis aff. (Wilson collection)
Hydrangea chinensis aff. (Wilson collection)
Hydrangea chinensis aff. (Wilson collection)
Hydrangea chinensis aff. (Wilson collection)

Clethra cavalieri about to come out. Small tree.

Clethra cavalieri
Clethra cavalieri
Clethra cavalieri
Clethra cavalieri

Dichroa ‘Cambridge Blue’ – excellent and a plant to get.

Dichroa ‘Cambridge Blue’
Dichroa ‘Cambridge Blue’
Dichroa ‘Cambridge Blue’
Dichroa ‘Cambridge Blue’

Styrax japonica ‘Evening Light’

Styrax japonica ‘Evening Light’
Styrax japonica ‘Evening Light’
Styrax japonica ‘Evening Light’
Styrax japonica ‘Evening Light’

Ripening seed on Illicium simonsii.

Illicium simonsii
Illicium simonsii
Illicium simonsii
Illicium simonsii

Dregea sinensis growing through a camellia.

Dregea sinensis
Dregea sinensis
Dregea sinensis
Dregea sinensis

Hydrangea anomala ssp. petiolaris (Emei shan).

Hydrangea anomala ssp. petiolaris
Hydrangea anomala ssp. petiolaris

Bowkeria citrodora from South America (rather different to the one Burncoose stocks).

Bowkeria citrodora
Bowkeria citrodora
Bowkeria citrodora
Bowkeria citrodora
Bowkeria citrodora
Bowkeria citrodora

Hydrangea chinensis aff.

Hydrangea chinensis aff
Hydrangea chinensis aff
Hydrangea chinensis aff
Hydrangea chinensis aff
Hydrangea chinensis aff
Hydrangea chinensis aff
Hydrangea chinensis aff
Hydrangea chinensis aff

Vaccinum padanifolium

Vaccinum padanifolium
Vaccinum padanifolium

Hydrangea luteovenosa (Japan).

Hydrangea luteovenosa
Hydrangea luteovenosa
Hydrangea luteovenosa
Hydrangea luteovenosa
Hydrangea luteovenosa
Hydrangea luteovenosa

Callicarpa formosana (FMWJ 14533) – a species new to us which looks like a viburnum. Introduced by Crûg Farm.

Callicarpa formosana
Callicarpa formosana
Callicarpa formosana
Callicarpa formosana
Callicarpa formosana
Callicarpa formosana
Callicarpa formosana
Callicarpa formosana

Hydrangea angustipetala with gorgeous bark. Fifteen feet in height and grown as a trio.

Hydrangea angustipetala
Hydrangea angustipetala
Hydrangea angustipetala
Hydrangea angustipetala
Hydrangea angustipetala
Hydrangea angustipetala
Hydrangea angustipetala
Hydrangea angustipetala
Hydrangea aspera Kawakamii Group

Hydrangea aspera Kawakamii Group
Hydrangea aspera Kawakamii Group
Hydrangea aspera Kawakamii Group
Hydrangea aspera Kawakamii Group
Hydrangea aspera Kawakamii Group
Hydrangea aspera Kawakamii Group
Hydrangea aspera Kawakamii Group
Hydrangea aspera Kawakamii Group

Hydrangea indochinensis

Hydrangea indochinensis
Hydrangea indochinensis
Hydrangea indochinensis
Hydrangea indochinensis

Hydrangea chinensis aff.

Hydrangea chinensis aff
Hydrangea chinensis aff
Hydrangea chinensis aff
Hydrangea chinensis aff
Hydrangea chinensis aff
Hydrangea chinensis aff

Rhododendron nuttallii from Vietnam – the best plants I have ever seen. Perfectly hardy.

Rhododendron nuttallii
Rhododendron nuttallii
Rhododendron nuttallii
Rhododendron nuttallii
Rhododendron nuttallii
Rhododendron nuttallii
Rhododendron nuttallii
Rhododendron nuttallii

Rhododendron maddenii (from Taiwan).

Rhododendron maddenii
Rhododendron maddenii
Rhododendron maddenii
Rhododendron maddenii

Hydrangea aspera Villosa Group

Hydrangea aspera Villosa Group
Hydrangea aspera Villosa Group
Hydrangea aspera Villosa Group
Hydrangea aspera Villosa Group

Hydrangea sargentiana from the original wild Borde Hill introduction plants.

Hydrangea sargentiana
Hydrangea sargentiana
Hydrangea sargentiana
Hydrangea sargentiana

Hydrangea aspera villosa – Gongshan – the best hydrangea today bar far.

Hydrangea aspera villosa – Gongshan
Hydrangea aspera villosa – Gongshan
Hydrangea aspera villosa – Gongshan
Hydrangea aspera villosa – Gongshan
Hydrangea aspera villosa – Gongshan
Hydrangea aspera villosa – Gongshan
Hydrangea aspera villosa – Gongshan
Hydrangea aspera villosa – Gongshan

Hydrangea anomala ssp. anomala from Sikkim growing up a tree and as groundcover. Rooted material was given to us. Huge leaves.

Hydrangea anomala ssp. anomala
Hydrangea anomala ssp. anomala
Hydrangea anomala ssp. anomala
Hydrangea anomala ssp. anomala
Hydrangea anomala ssp. anomala
Hydrangea anomala ssp. anomala

The very rare Rhododendron goreri which is close to Rh. nuttallii.

Rhododendron goreri
Rhododendron goreri
Rhododendron goreri
Rhododendron goreri
Hydrangea species unknown (Monkey Bridge, Yunnan).

Hydrangea species unknown
Hydrangea species unknown
Hydrangea species unknown
Hydrangea species unknown
Hydrangea longipes with very long petioles and excellent flowers.

Hydrangea longipes
Hydrangea longipes
Hydrangea longipes
Hydrangea longipes
Hydrangea longipes
Hydrangea longipes
Hydrangea longipes
Hydrangea longipes
Hydrangea indochinensis

Hydrangea indochinensis
Hydrangea indochinensis
Hydrangea indochinensis
Hydrangea indochinensis
Hydrangea indochinensis
Hydrangea indochinensis
Hydrangea aspera Villosa Group – yet another unconventional form.

Hydrangea aspera Villosa Group
Hydrangea aspera Villosa Group
Hydrangea aspera Villosa Group
Hydrangea aspera Villosa Group
Hydrangea aspera Villosa Group
Hydrangea aspera Villosa Group
A pure white flowered form of Clerodendron trochotomum.

Clerodendron trochotomum
Clerodendron trochotomum
Clerodendron trochotomum
Clerodendron trochotomum
Carbutilon from Mexico I think.

Carbutilon
Carbutilon
Carbutilon
Carbutilon
Hydrangea scandens x Hydrangea serrata – as dwarf as it gets.

Hydrangea scandens x Hydrangea serrata
Hydrangea scandens x Hydrangea serrata
Hydrangea scandens x Hydrangea serrata
Hydrangea scandens x Hydrangea serrata
Aeschcananthus in the glasshouse trailing from a basket.

Aeschcananthus
Aeschcananthus
Aeschcananthus
Aeschcananthus
Deinanthe bifida and Deinanthe caerulea – hydrangea relative.

Deinanthe bifida
Deinanthe bifida
Deinanthe bifida
Deinanthe bifida
Deinanthe caerulea
Deinanthe caerulea
A rare form of Lilium nepalense – very different to the one Burncoose sells.

Lilium nepalense
Lilium nepalense
Camellia chengii full out in late July! This will clearly be out in August too so camellias all year round.

Camellia chengii
Camellia chengii
Camellia chengii
Camellia chengii
Camellia chengii
Camellia chengii
Camellia chengii
Camellia chengii
The dwarf growing and very rare Magnolia coco from Vietnam and Taiwan with buds.
Magnolia coco
Magnolia coco
Magnolia coco
Magnolia coco
Psidium cattleanum – Starberry Guava in flower.

Psidium cattleanum
Psidium cattleanum
Psidium cattleanum
Psidium cattleanum
A pure white Dichroa.

Dichroa
Dichroa
Dichroa
Dichroa
Magnolia dandyi (Manglietia megaphylla) in the glasshouse with orange indumentum on the new growth. May be hardy enough for outside.

Magnolia dandyi
Magnolia dandyi
Magnolia dandyi
Magnolia dandyi
Magnolia dandyi
Magnolia dandyi
Clematis tubulosa (I think).

Clematis tubulosa
Clematis tubulosa
Clematis tubulosa
Clematis tubulosa
Magnolia crassipes still in flower. The true species (unlike ours).

Magnolia crassipes
Magnolia crassipes
Magnolia crassipes
Magnolia crassipes
Hydrangea aspera villosa – from Roy Lancaster (2021).

Hydrangea aspera villosa – from Roy Lancaster
Hydrangea aspera villosa – from Roy Lancaster
Hydrangea aspera villosa – from Roy Lancaster
Hydrangea aspera villosa – from Roy Lancaster
An unnamed Callicarpa species with furry and rather tropical looking leaves.

unnamed Callicarpa species with furry and rather tropical looking leaves
unnamed Callicarpa species with furry and rather tropical looking leaves
unnamed Callicarpa species with furry and rather tropical looking leaves
unnamed Callicarpa species with furry and rather tropical looking leaves
An unnamed Callicarpa species with red undersides to the leaves.

unnamed Callicarpa species with red undersides to the leaves
unnamed Callicarpa species with red undersides to the leaves
unnamed Callicarpa species with red undersides to the leaves
unnamed Callicarpa species with red undersides to the leaves
An unnamed Callicarpa species which may perhaps be Callicarpa kwangtungensis? Similar leaves but not coloured like those in the nursery.

unnamed Callicarpa species which may perhaps be Callicarpa kwangtungensis
unnamed Callicarpa species which may perhaps be Callicarpa kwangtungensis
unnamed Callicarpa species which may perhaps be Callicarpa kwangtungensis
unnamed Callicarpa species which may perhaps be Callicarpa kwangtungensis

Following our visit to Tregrehan I received this email from Tom:

From: Tom Hudson
Sent: 12 August 2020 16:12
To: Charles Williams PA
Subject: HYdrangeas

Hello Charles,
The reply from Maurice was interesting on a couple of points.
But as he pointed out the latest taxonomic revision doesn’t really help us at all horticulturally….whats new?

H. petiolaris is elevated to full species status.
H. scandens chinensis and angustipetala have both been lumped into chinensis.
H. davidii in his opinion warrants specific status although it is lumped into chinensis by McClintock.

We forgot to look at H. longifolia which I really rate as a plant, lovely foliage although flowers a bit on the small side.

I will propagate the white Dichroa as I need to trial it outside properly.

The later flowering villosa collections looking really good now.

No new update on the Callicarpa info from KR on his Vietnam one but he is due a visit soon.

All the best,
Tom

Back to 26th July 2020.