The plant collections at OpdeHaar gardens –
WOODLAND (Shade tolerant) PLANTS
On this page you will find information on and/or photos of anemone, aralia, begonia grandis, calanthe, cardamine, chloranthus, epimedium, helleborus, impatiens(bizzy lizzy) mosses, mushrooms, podophyllum, dysosma, polygonatum, (smilacena, disporum, disporosis), pulmonaria, tiarella, trillium and more woodland plants. Under Miscellaneous there are photos of the following plants: allium ursina, arum, asarum, chrysosplenium, cornus, deinanthe, diphylleia, hacquetia, hepatica, lamium, lysichiton, mandragora, mertensia, mukdenia, omphalodes, pachyphragma, peltoboykinia, pollemonium, rabdosia, rubus,sanguinaria, saruma, soldanella, tricytris,uvularia, vinca. Don’t forget to look at aroids,araceae, hosta en varens – also woodland and shade tolerant plants.
All photos were taken in our garden.
Click on the photos for a larger image, a slideshow and sometimes extra information.
Why is a plant shade – tolerant?
Click here to learn why some plants are shade tolerant. In order to better understand the behaviour and needs of plants grown in either sun or shade, it is helpful to familiarise oneself with some basic botanical principals of photosynthesis and plant nutrition. I have chosen to include this summary as a prelude to the review of shade-tolerant plants because these are ones which have had to adapt their prime food-making mechanism (photosynthesis) to reduced levels of sunlight which is the energy provider of this process.
Begonia grandis ssp. Evansiana is fairly widespread throughout China and Japan and its common name of “Hardy begonia” sums up a major claim to fame for it’s inclusion in the hardy exotic hall of fame. It came through the winter of 2008/9 in our gardens without any special protection but I think I would cover it in dried leaves if temperatures dipped below – 10 deg C or so.
As the photo indicates, it is instantly recognisable as a begonia even to people who profess to know nothing about plants and maybe it is this very familiarity which induces many gardeners to walk past it thinking that it is a pot plant which has been pushed in for the summer to fill an otherwise embarrassing space until a more permanent planting can be devised. Nothing could be more wrong – stop and look more closely ! If the planting can be arranged, try and position it so that the spectacular red undersides of the leaves are visible.A side view of the plant or looking up at it on a slope are two ways of achieving this.
As if all this isn’t reason enough to get hold of a plant, it thrives in quite deep shade and although moisture is preferred, I find that it can cope with dry conditions and a fair level of sun once a plant is established. Once the first frosts arrive, the bit of the plant above the ground dies off but the rootstock lives on to emerge the following spring – reports on the Internet hint that this emergence is ”late”. In my limited experience, I find that it is the extent of exposure to sun which is a major factor here; in heavy shade, it can be towards the end of April before growth is seen but, even after a normal winter I saw signs of life in a sunnier position as April started. It could possibly be related to the extent to which the soil has been warmed. As growth gets underway, you will almost certainly become aware of a crop of little seedlings which can be potted up and will grow away very easily. These are the result of bulbils which form in the leaf axils of the plant. By this time, I can imagine that you are wondering where “the catch” is in this story and I can honestly say that I haven’t managed to find it yet ! This is a wonderful shade plant and it isn’t at all difficult either to propagate or grow and it isn’t invasive although it provides offspring enough (bulbils) for bulking up a group. It is a mystery to me why one doesn’t see it (yet) in all the garden centres. Normal flower colour is pink but there is also a white or “Alba” form.
Tony Avent of the well-known Plant Delights nursery in USA summaries the genus Chloranthus characteristically succinctly:
“ Chloranthus, a genus of 17 species of easy-to-grow Asian perennials, are among the most esoteric perennials we grow. They are valuable for their bold texture in the woodland garden and really funky flowers in late spring. Chloranthus plants produce dark green leaves that in some species are reminiscent of hydrangea. The leaves, held on 2-3′ stems, are topped in May with a spike of small, white, bottlebrush-like flowers that are fragrant in the morning.
In China, chloranthus flowers are added to tea to impart a unique sandalwood-like scent and in south-east Asia the leaves are also used to make tea. Chloranthus is considered by palaeontologists to be one of the basal angiosperms…in plain English, they think chloranthus represents one of the earliest, most primitive flowering plants. So now you know enough about chloranthus to enthral people at your next dinner party…trust me, you’ll be a hit.
Chloranthus prefers a part shade site with well-drained, consistently moist soil. This is a very easy plant to grow, and you certainly can use it to fool your know-it-all plant geek friends, too.”
For people who are looking for more botanical details, there is an interesting table in Flora of China which guides one through identifying the different varieties of Chloranthus. Our first encounter occurred one spring about 3 years ago when a plant with shiny, black leaves almost called out to us across one of Bob Brown’s poly-tunnels at Cotswold Garden Flowers nursery in UK. It was labelled Chloranthus fortunei “Domino” but current thinking is that it is actually C. sessilifolius “Domino” and the picture on our website shows it growing robustly in a moist spot which gets mid to late afternoon sun in our garden. Apparently, C.fortunei is growing on the rockery at the RHS Wisley Garden in UK which maybe indicates that at least some members of the genus are comfortable in sunny conditions – I hasten to add that I’ve not seen the situation myself. I do know that my own plant lets me know when it is getting a bit dry so the “photosynthesis-transpiration compromise” is probably an issue with the plant. As the season progresses, the spectacular dark leaf colouration of Spring gradually reverts to dark green. Our plant gave us a generous crop of seed in September and these have been freshly sown here and portions given to two plant nurseries; if we get successful germination(s) then details will be posted. Recent queries (August 2015) around the nursery trade here in The Netherlands revealed that propagation work is going on with at least two Chloranthus species – C.oldhamii and C.fortunei. I have small plants of both these species from Dutch nurseries and need to be sure that they are what they say they are in the light of what I just said regarding the “Domino” variant. While our plant vindicates Tony Avent’s remark about being very easy to grow, propagating the plant by division is reported not to be easy in the sense that a high proportion of the plants die. I don’t have more details but the reports were enough for me not to try splitting my single specimen. Ironically, just as I was resigning myself to having a plant that probably wouldn’t have commercial appeal to my nurseryman friends, I came across a nursery in The Netherlands which seems to have resolved any propagation problems and offers small C. fortunei plants – http://www.kwaliteitsplanten.nl/chloranthus. Lovely quality plants were sent by mail towards the end of August and have since grown robustly to the extent that I have had to re-pot them at the start of October and they will be over-wintered in a greenhouse . If they do emulate the “Domino” variant, then the nursery has a potential hit on it’s hands especially as it was said that the plants came from tissue culture propagation. The saga continues!!
Epimediums come in hundreds of variants and the photos here show a fraction of what you can see in the gardens. The majority are happy in shade and generally cope well with dry conditions. They spread by rhizomes and some, such as the E.X youngianum hybrids, are vigorous enough to be considered as good groundcover candidates. The old leaves can be clipped off in early February to render the Spring flowers better visible – you can do the Hellebore leaves at the same time! Wikipedia gives a quick review of the genus : https://en.wikipedia.org/wiki/Epimedium but the standard text is W.T.Stearn’s “The Genus Epimedium” (ISBN 1 84246 039 0). The scope of this book extends to other members of the Berberidaceae family, notably Podophyllums and is useful for the shade/woodland gardener. They have medicinal uses in traditional Chinese medicine and there is more on this on the Internet than on their role as garden plants!
Gardeners have access to a variety of different species of hellebore but the following notes are restricted to H.niger, H.orientalis and their hybrids. In short, the colourful plants which together with snowdrops, herald a new gardening year. Graham Rice has written an excellent reference for anybody interested in all aspects of hellebores. I actually agree with Mr Rice, “Buy the book”. The Christmas Rose, H.niger, is found naturally in Alpine woodlands and it’s white flowers are frequently shown poking through a layer of snow although this is invariably sometime after Christmas in real-life gardens! The flowers of the natural species do rather “hang their heads” and point towards the ground but various selections and hybrids are increasingly available where flowers are more visible and outward facing – fully upward-facing flowers can be damaged by snow and rain.
Something of what is going on to expand the range of Hellebore hybrids available is revealed by Thompson & Morgan and both Internet and literature such as the earlier reference to Graham Rice, reveal a wealth of additional information. Some plants available in garden centres are stunning in the numbers of flowers, buds and leaves and have captivated several visiting friends who have presented them to us as presents over recent years. Many such plants have been forced and brought to undoubted visual perfection in a greenhouse but can be unbelievably pot-bound. I’ve had and seen spectacular plants which, on being slipped out of their pot, reveal just a solid, impenetrable mass of roots with no visible compost at all. Successfully planting these out into the garden is all but impossible so be warned and check any plants before you are tempted into a purchase.
The key to successfully cultivating Hellebores (and any plant) is to be cognisant of their natural growing conditions. H.niger from Alpine woodlands appreciates some lime in a well-drained, humus-rich soil with light shade. They hate wet conditions. H.orientalis and hybrids are a bit more tolerant and do acceptably well even in lightly acidic soils and can take more sun. For owners of country woodland gardens, these hellebores are also rabbit and deer-proof! Here in our gardens, conditions can be very acidic and we have calcifuge shrubs such as rhododendrons and camellia which aren’t regular companion plants for hellebore hybrids. While I do occasionally spot-treat the hellebores with lime, my usual trick is to put bits of cement amongst their roots (+ mycorrhizal booster) when I plant them. Bearing in mind that plants are forming buds and getting into growth in the winter months, a top dressing and some general fertiliser in Autumn is also beneficial. Carefully cutting away old leaves prior to flowering lets one appreciate the flowers better.
|Helleborus with netnecrosisi virus or “Black Death”. Fortunately NOT in our garden.|
Hellebores are generally fairly problem-free but one does need to keep a careful watch out for “Black Death” … Hellebore ne Virusnecrosis virus ( HeNNV) or “Hellebore black death” is something which, once seen, is readily recognisable and the RHS have a succinct review on this incurable and invariably fatal affliction. It is a virus disease spread by aphids and the symptoms are not always immediately apparent such that somebody like a specialist nurseryman or collection holder can be faced with destroying his stock plants. The one saving grace is that the disease does not transmit via seeds. It is important to realise that sharply defined, circular black spots on leaves are symptoms of another type of fungal infection which is treatable (burn the leaves and spray with fungicide). If this disease becomes a severe problem or there are reports in one’s neighbourhood, one should consider the quarantining of newly purchased plants for a season and treating hellebores to keep them free of aphids.
Having talked about hardy begonias, it seems fitting to introduce the hardy version of “Busy Lizzy” or, more grandly and correctly, Impatiens omeiana. This plant was originally found in 1983 by Don Jacobs on the famous Omei Shan ( Mount Emei) in S.E. Sichuan, China. It is a beautiful foliage plant, around a foot high, which excels in moist shade and slowly forms a clump. As autumn arrives, yellow trumpet-shaped flowers appear but , like the begonia, it is really a plant which one grows for its foliage.
Speaking personally from here in The Netherlands, it is currently even more difficult to find than Begonia grandis and I only managed to get my plants in the spring of 2009 and I have only had it now through one winter. However, I took the precaution of covering the planting spot with a small strip of bubble plastic at the end of November primarily to keep out excessive moisture. I removed this in mid-March and new shoots were visible by the start of April. Elsewhere, no precautions were taken and shoots appeared around the same time. My conclusion is that Impatiens omeiana is hardy in the Netherlands to at least -10 deg C.
Time passes by (2014) and any question as to the winter hardiness of Impatiens omeiana can be safely discounted. Despite this and it’s ease of propagation, it is still a bit of a rarity in the Dutch nursery trade and isn’t seen in garden centres. At least two variants are reported by specialist nurseries. ”Ice Storm” features a plant where the attractive leaf variegation of the sort is rather masked by a sort of haze over the leaf. Although I’ve seen it in both Dutch and UK nurseries, it is for my taste less impressive than the original Impatiens omeiana. To my mind , a far more attractive and currently rarer variant is a dark leaved, attractively variegated variety that appears on the Internet as ”Silver Pink” or ”Silver and Pink”.
|Root system of Impatiens omeiana “Sango”|
I recently came across a dark leaf form at Pan Global Plants and the owner, Nick Macer, had christened it ”Sango” – it looks very similar to ”Silver Pink”. He had found it in a batch of plants at/from a Danish nursery. The RHS and general nursery trade in Europe are now generally referring to the variegated dark-leaved variant with its pink leaf veins as “Pink Nerve“. Anyway, putting all taxonomic considerations to one side, this dark-leaved variant of Impatiens omeiana is well worth looking out for.
As Spring 2017 breaks, I have to smile at any doubts I had as to the hardiness of Impatiens omeiana and the Sango/Red Nerve variants. With the shelter of a woodland, this impatiens is pushing through by the first weeks of March when night frosts are still occurring. What has also become clear is that the Sango/Red Nerve variant is significantly more vigorous than the sort and spreads from a rhizome which forms an almost inpenetrable network a few centimeters under the surface of the soil. The photograph gives you an idea of what is going on under the soil surface. This can easily overwhelm smaller plants and my advice is to put in something like a section of plastic lawn edging in cases where the advance of the impatiens needs to be controlled.
We have several different sorts of mosses in our garden. These plants multiply by producing spores, just like ferns, but simpler in structure. They have stems and leaves, but no real roots, just stems which change to have rootlike appendages, rhizomes. There are 3 important sorts of mosses – leafmoss, livermoss and crustmoss. Often all 3 sorts are seen in the same area.
Leaf mosses form spores in caps from which they either are slung through small openings or they are released via 4 splits, or the most usually, through an opening in the mouth which becomes visible when the cap has fallen off.
Livermoss are either flat and lobed or they have small leaves in 3 rows. Crustmosses are formed from mould in close relationship (symbiosis) with another plant.
Mosses growing on tree stumps Haircap moss (Polytrichum commune), cushion moss ( leucobryum glaucum ), greenshield lichen (parmella caperata)
We are certainly no mushroom or fungi experts, but every autumn, particularly after wet weather, we are confronted with with all sorts of mushrooms in the wood. I hope that the identification is correct, but don’t trust it. Mushrooms such as sulfur tuft (Hypholoma fasciculare), the shaggy ink cap (Corprinus comatus), oyster mushroom (Pleurotus ostreatus) and turkey tail mushroom (Trametes versicolor) grow on dying wood but do not attack living wood.
Click on the photos below to see mushrooms and fungi in our wood. (Terug = Back)
Podophyllums are ideal foliage plants for moist, lightly shaded positions in the garden and are perfect subjects for woodlands. Taxonomically, along with a surprising number of other woodland species, they are included in the Berberidaceae family. There is a wealth of information to be found on the Internet on the various varieties and I will therefore provide an overview of my experiences in our garden which will hopefully be of supplementary interest to gardeners, particularly in northern Europe. Podophyllum peltatum occurs naturally in the eastern part of USA up into Canada and is readily available from garden centres. It forms clumps from a spreading rhizome and is fairly fool-proof when kept moist and not exposed to intense sunlight. It generally flowers white in May and red fruits form under the covering leaves. Dan Hinkley reports that a pink flowered variant (P.peltatum var. deamii) occurs. Barring this, the plant is fairly consistent in form which is not the case for its Asiatic counterpart, Podophyllum hexandrum, which is widely distributed from N.E. Afghanistan through the Himalayan area into China. There is variation in both leaf form and flower colour but suffice it to say that a major difference from P.peltatum is the attractive black marking on the leaf surfaces. Gardens with frost pockets and/or places where night frosts occur until late in the spring can give problems because P.hexandrum can be damaged and, in extreme cases, weakened to the extent that it eventually fades away.
There are several other Asian Podophyllums having the general characteristic of highly decorative leaves which are still often encountered under the nomenclature “Dysosma” rather than “Podophyllum“; rarely, one also encounters “Sinopodophyllum” but this nomenclature was never officially recognised. These highly decorative Asian podophyllum varieties are generally expensive and, in my experience, rather more temperamental than their plainer family members. That said, varieties such as P.veitchii ( P.delavayi) and P. difforme invariably cause garden visitors to stop and comment. If only they could be readily propagated and induced to grow with the ease of P.peltatum!! Such sentiments and no doubt the commercial reward awaiting a plant catering for these needs most probably lay behind the development of a new hybrid rejoicing in the unforgettable name of Podophyllum “Spotty Dotty”.
Podophyllum “Spotty Dotty” is illustrated in the accompanying photos and is a complex hybrid described in US plant patent PP17361. Most interesting commercially is that it is reported to come true from tissue culture micro-propagation and this is evidenced by its relatively easy availability in the trade. The seed parent was a complex hybrid of Asian Podophyllums from Japan which was pollinated by a selected P.delavayi plant. As the photos illustrate, it is a highly decorative plant and I obtained it some years ago from a local nursery, De Hessenhof. Over about 3 years, it slowly formed a small clump and then the central area just seemed to disappear but then it was as though numerous seedlings were appearing and these had every appearance of “Spotty Dotty”. In all honesty, I didn’t investigate matters too closely because I was busy elsewhere and just thankful that I suddenly had a potential load of “seedlings” to plant in other locations so I really can’t say exactly what caused this but the seedlings have transplanted without any problems whatsoever. One possible explanation is that the rhizome was damaged during excessively wet winter conditions resulting from a blocked drainage ditch and this effectively provided me with a host of root cuttings. Whatever, “Spotty Dotty” is a lovely addition to the woodland garden and here at “Op de Haar” is as temperament-free as P.peltatum.
For completeness, I should add that there is also another commercial Podophyllum hybrid which is called “Kaleidoscope” which uses the same seed parent as “Spotty Dotty” but a different pollen parent and is described in PP14460. I have no experience with this hybrid but it does indeed have very attractively marked and patterned leaves. When I saw young plants of “Kaleidoscope” for sale, they struck me as being significantly less decorative than “Spotty Dotty” and there was a caution about susceptibility to excess winter cold, I consequently didn’t buy any. However, I have since seen various reports praising the decorative value of the plant and reference to illustrations collected over the Internet reveal a staggering variation in leaf patterns. To what extent this variability stems from variations in the hybrid itself or from its age or position, I do not know, but there do appear to be young plants with highly patterned leaves available in the trade. To judge from the literature it appears that US nurseries are active in podophyllum hybridisation and there is a very informative article by Dan Heims which gives interesting insights into this. In the light of my earlier comments, his remarks on cold-susceptibility are very noteworthy.
Under Miscellaneous there are photos of the following plants: allium ursina, arum, asarum, chloranthus, chrysosplenium, cornus, deinanthe, diphylleia, hacquetia, hepatica, lamium, lysichiton, mandragora, mertensia, mukdenia, omphalodes, pachyphragma, peltoboykinia, pollemonium, rabdosia, rubus, sanguinaria, saruma, soldanella, tricyrtis, uvularia, vinca
Click on the photo below to see more woodland plants in our garden (Terug = Back)