Wednesday, 26 August 2009

Hardy Impatiens

I keep on telling people that these things are hardy but they don't really believe me. The look on their face says 'Yes but not really', and I say, no, they've all survived outdoors in the ground both here and on our heavy soil at home, and they still don't really believe it, but I can promise you. There is in fact a narrow shady raised bed at the nursery only 6ins deep over the Mypex where three of them - arguta, uniflora and puberula are in danger of taking over. They even seem to do quite well in dry shade under shrubs. Almost too good to be true.
People are always wanting plants for shady places that flower on and on all summer. Well here they are. Come and get them...

Impatiens arguta, originally uploaded by peganum.
Impatiens arguta
Impatiens arguta
A vigorous and hardy species with long tubular purple flowers on red stems. Ideal for moist shady situations and flowering all summer. My stock plant here is about 2ft high and has come through the last few winters without trouble. has also grown well in my mum's garden, on a chalky soil, in quite dry shade.
Impatiens arguta
A large plant in the border at the nursery in late October. What's not to like?
2L pots ~ £6

Impatiens uniflora
Impatiens uniflora
In many respects a miniature version of arguta with dainty little rosy pink flowers. Just as vigorous though, spreading underground. Another ideal plant for providing late summer and autumn colour even in deep (but not too dry) shade.
Sold out

Impatiens omeiana
Impatiens omeiana & Corydalis Blackberry Wine
Probably the best known of the hardy Impatiens, and a bit of a classic. There are several forms in cultivation and in this one the leaves are a very dark velvet-green with strong pale variegation along the veins and wine red undersides. The flowers are amber coloured and appear right at the end of the season. For moist woodsy soils in shade, but not with delicate things as it does run.

Impatiens puberula

Another hardy purple flowered species, this time with soft green, somewhat fuzzy foliage. The flowers are more chubby with dark purple lips and a paler 'bag' behind, if you see what I mean.
Needs the same conditions as arguta but is more spreading as the stems root where they touch the ground.


Impatiens stenantha
Impatiens stenantha
Another excellent hardy species for exactly the same conditions as the others. The foliage and stems have a distinct wine purple tint.
1L pots ~ £6

Please please please, may I humbly request that you check with me that the plants you require are in stock before you order? Otherwise we'll have to arrange refunds. 
Thank you so much.

Caryopteris divaricata

Caryopteris divaricata
The name Caryopteris is usually associated with a bunch of rather grey twiggy subshrubs grown mainly because they flower very late in the season (C. x clandonensis and the like). C.divaricata is very different - making a lush green upright bush and dying down completely in winter. The late flowering is the same but the flowers themselves are much more interesting as can be seen from the photo. Those of you who know the tropical Clerodendron (or Rotheca) myricoides (or ugandense) would be right in thinking they look suspiciously similar, with those long curling filaments and rounded purple blue petals. They are related.
Caryopteris divaricata & Thladiantha dubia
Another well-known purveyor of rare plants describes the flowers as merely ‘harmless’ which I think is a bit unfair. They’re not huge or especially plentiful, but they are beautifully crafted and jolly pretty. The only down side is the foliage which has an odd odour (one customer calls it The OXO plant) so don't plant it too near the path unless you like that sort of thing. Also the stems are quite brittle so best planted amongst other things out of the wind.
Totally hardy and very adaptable. I will soon have a few of the pink flowered form available too.
3L pots ~ £8

Sunday, 23 August 2009

Hardy herbaceous Hibiscus

Hibiscus moscheutos
Another entirely neglected group of extraordinary hardy North American herbaceous perennials (yes I did say Hardy Perennial). That flower above is a good 6 ins across. The plant is fully herbaceous, dying down completely in winter.
Hibiscus coccineus and coccineus x moscheuto
What's the catch? I hear you ask. Why isn't everyone growing it if it's so fabulous?
The answer is that, like many plants from the south-eastern states of the USA, although totally frost hardy it is used to a very hot summer with high humidity and plenty of moisture at the roots (see my article on summer rainfall climates). Not always easy to provide here. The hottest spots in many British gardens will also be the driest, and hardy hibiscus are often wetland plants in the wild. The result is that your plants might not even appear until June or even July and may struggle to get big enough to flower before the frost cuts them down again.
What's to be done?
a. Choose a place in the garden that gets the longest period of sun possible. A south or south-west facing aspect is good. Anyway, choose one that is totally open to the sky.
b. You should definitely make sure the site is as well mulched and fed as possible. Clay suits them well but may be slow to warm up so add plenty of organic matter.
c. Hardy herbaceous hibiscus often live in seasonally flooded sites in the wild so contriving some sort of mini bog garden with a small pond liner would not be going too far. Extra irrigation would not go amiss and you could grow them in a hole or trench as you would celery.
d. Talking of vegetables, market gardeners have all sorts of tricks for warming the soil for early crops - cloches, black plastic, fresh manure mulches etc.
All this may seem like a lot of faff to go to, and for most ordinary garden plants that would be true but I believe there are some plants that are just so remarkable they are worth the extra effort. Hibiscus coccineus and it's relatives are just such plants. If all else fails you can start them off in a pot in an unheated greenhouse as you would some Hedychium.

Hibiscus coccineus
H. coccineus a fabulous tall elegant species with huge vivid scarlet classic hibiscus flowers and narrow red tinted Acer palmatum-like foliage.
Hibiscus coccineus
Very fine.
Sold out

H.coccineus Texas White 
Hibiscus coccineus Texas White
Like the normal red form, but with (you guessed it) pure white flowers. The foliage has somewhat broader segments too, and the whole plant is plain green.
Sold out

Hibiscus moscheutos
An amazing hardy species, but where coccineus is a study in class and elegance, moscheutos is blousy and over-the-top. A much shorter plant (about 3ft high and much bushier) with large, soft oval leaves and enormous (8-10 in!) flowers usually in some shade of red pink or white, with a darker eye. Has to be seen to be believed. Hardy and perennial but easier to grow quickly for summer bedding.
Sold out

Hibiscus palustris
H.palustris - may or may not be a subspecies of moscheutos. Anyway, a less 'in your face' form. Palustris means 'of wetland' but I'm not sure it needs more water than the others - just don't skimp on the irrigation with any of them.

H.moscheutos x coccineus - should be intermediate between the two species. The seedlings so far are indistinguishable from coccineus.
Sold out

Hibiscus militaris
H.militaris - a medium sized species with large, dark eyed white flowers. 
Sold out

Saturday, 15 August 2009

Salix gracilistyla melanostachys

Salix gracilistyla melanostachys, originally uploaded by peganum.
A very wacky willow for you, this time grown for it's bituminous black catkins in early spring which sprout pale yellow anthers and have red highlights.
It's hard to get a good shot of this from a distance with any 'interference' in the background, but the black catkins, (see photo below) are striking. Potentially a large shrub but responds well to quite hard pruning immediately after flowering.

4L pots ~ £16

Monday, 10 August 2009

Desmodium elegans (aka tilifolium)

Desmodium elegans
Soft green foliage and profuse mauve flowers over a long period in late summer and autumn.
Easy, hardy and floriferous here.
Fully hardy in a wide variety of conditions.
5L pots ~ £15

Desmodium elegans albiflorum
Desmodium elegans white

The rather lovely white flowered form
Sold out

Please please please, may I humbly request that you check with me that the plants you require are in stock before you order? Otherwise we'll have to arrange refunds. 
Thank you so much.

Saturday, 8 August 2009

Senna hebecarpa

Senna hebecarpa
I'm not sure why the North American Sennas are not better known in the UK. I know two of them reasonably well - hebecarpa and marilandica (both sometimes included in Cassia.) The former seems to be the better of the two. They're big exotic looking plants but completely hardy given their distribution as far north as the Great Lakes.
The foliage is lush and the flowers give a good show in the latter part of the summer.
Senna hebecarpa
Ideal for prairie type plantings with other native Americans (so to speak) they grow well in moist rich soils in full sun but should tolerate some shade and drought.
3L pots ~ £10

Saturday, 1 August 2009

Osmanthus decorus

Osmanthus decorus, originally uploaded by peganum.
A very smart and hardy evergreen suitable for a wide variety of situations. The foliage is a very dark green with pale mid veins on nicely contrasting maroon stems. The flowers are creamy and honey scented and produced in profusion in spring.
Ideal for rather dull dry sites among trees but not in deep shade (for there, try Skimmia or Sarcococca). Up to 6ft high and across but may be trimmed over after flowering. A reliable, adaptable shrub, not often seen, and apparently endangered in the wild.
3L pots ~ £10

Tinantia pringlei

Tinantia pringlei, originally uploaded by peganum.
A hardy Mexican relative of the popular houseplant Tradescantias. It dies back completely in winter but comes back strongly from the roots in spring forming a dense ground-cover. The foliage is black spotted (not diseased) and there is a succession of the little three-petalled mauve flowers through the summer.
Completely hardy through the last few winters here in Sussex, and in fact inclined to turn up in unexpected places around the garden.
clumps lifted from the ground - £5 

Please please please, may I humbly request that you check with me that the plants you require are in stock before you order? Otherwise we'll have to arrange refunds. 

Thank you so much.