In this guide we will be discussing 10 best plants to fill in your rock gardens.
Rock gardens are one of the most unique types of gardens that you can have, but with proper care for the plants that grow in the garden, you can have a beautiful place where plants can flourish. For this to occur, you are going to need to have plants growing there that can grow in areas with poor soil that may not get adequate water all of the time. There are a lot of plants that fall into this category, but in this guide, we will be considering 10 of the best to fill in your rock garden.
- 1. Douglas Moss Phlox
- 2. Yellow Alpine Alyssum
- 3. Blue Fescue
- 4. Prickly Pear Cactus
- 5. Rock Cress
- 6. Hens and Chicks
- 7. Coral Bells
- 8. Thyme
- 9. Sedum
- 10. Aubrieta
- New Zealand Plants and their Story
- The beauty of Alpine Plants with the RHS Wisley team
- 10 great plants for a living roof
1. Douglas Moss Phlox
The leaves of this plant are dark green in color with a needle-like shape that is going to look great amongst the rocks of your garden. It tends to grow best in areas with a moderate temperature, but in is capable of growing in cooler environments as well. Typically, the blooms on this plant are shades of pink and purple. This is a plant that has a longer stem, which means that it will be able to cover rocks and add depth to your garden.
2. Yellow Alpine Alyssum
Adding yellow to your rock garden is a great way to brighten it up. This plant is a soft yellow, which makes it perfect as a plant that blooms in the spring. It is easy to grow; the plant is resistant to drought conditions, and it can thrive in soil that holds very little nutrients. Since this plant thrives in sunny conditions, it may have difficulty growing in shady areas or areas that get cold for part of the year.
3. Blue Fescue
Not many rock garden owners would consider an ornamental grass such as blue fescue for their garden, but it can be a great addition, especially considering the blue coloration that will make the rocks look more vivid. This plant will need to be in an area where it gets full sun so that the leaves can turn blue, and when it is maintained, the grass will create and maintain a sphere-like shape that is unique.
4. Prickly Pear Cactus
Many rock gardens are not tended to every day, which is why they need to be filled with hardy plants that will be able to take a lot of heat and sun as well as very little water. Drought resistant plants are typically best, which is why the prickly pear cactus is a great option. Of course, this cactus is going to have spines on the leaves, so you will need to take care while planting it in your rock garden. In addition, the pears on this plant are edible, which means that if you live in growing zones 10 or 11, you can even have a bit of extra fruit to enjoy throughout the year.
5. Rock Cress
If you are looking for a plant that will cover the rocks in your garden, the rock cress is a great option that will give your garden a softer look. This is a plant that does best in full sun, but it also requires quite a bit of moisture to survive. In fact, it tends to grow like moss, which means that moist ground will be beneficial for its growth. The blooms that these plants produce can be any color from blue and deep violet to a soft pink or lavender.
6. Hens and Chicks
Hens and Chicks are great plants for any rock garden because these small plants multiply as they grow, and because of their size, they are able to creep into the smallest spaces in the garden to make it fuller. They do not need a lot of water to grow, which makes them ideal for rocky soil that will not retain water. This is a flowering plant, but it is a great addition to the garden at any time because of the red, pink, and purple highlights that can be found on the leaves. Because these plants are so easy to grow, you will find them throughout the county.
7. Coral Bells
Many of the plants that we have considered thus far for a rock garden have had some type of green foliage to cover the ground and the rocks in the garden, but coral bells have much more colorful leaves that will brighten your garden throughout the year. Though the plant does bloom ,the pink and purple leaves are striking against the green foliage of other plants.
Thyme is a very decorative plant that will look great in a rock garden. You can use the plant to decorate a specific area of the garden, or if you prefer more of a cover, a creeping variety is a great option to consider. Typically, the leaves are small and bright green, while the leaves are a light lavender or purple shade. Once the plant grows, you will be able to use the herbs to season your food as well.
Also known as stonecrop, sedum is a great plant to consider for a rock garden. It is a succulent, which means that it will not require a lot of water to thrive, and it can take the heat of the sun without any issue. The blooms that this plant produces are star-shaped, which makes them stand out in most rock gardens. This plant is available in a variety of bloom colors, so you can use these plants to brighten up your rock garden quite a bit.
If you want to brighten up your rock garden with purple flowers, then aubrieta is a great option to consider. It has small leaves and flowers that can easily grow between the rocks, and since it is a carpeting plant, it will spread to all of those hard to grow in places with ease. Typically, the blooms on this plant can vary in shade, so you can vary your garden a bit.
There are quite a few plant options for a rock garden; some add cover to the space, while others add color. Regardless of the plants that you choose, you will want something that grows well in rocky soil and can handle sun all day. Which plants do you find grows best in a rock garden?
Popular Garden Ideas
Popular Garden Ideas
When it comes to picking plants, these are Mitchell’s choices for a long-lasting container garden:
Rock jasmine. Photograph: Alamy
Rock jasmine (Androsace carnea subsp brigantiaca) From the south-western Alps. Forms cushions of open rosettes with fragrant white flowers in spring.
Wood sorrel (Oxalis ‘Slack’s Peacock’) One of Mitchell’s own hybrids, bred for its large, pink blooms with blue centres and good scent. Hardy, reliable and perfect for containers.
Globe daisy. Photograph: Alamy
Globe daisy (Globularia meridionalis) Slow-growing evergreen which produces blue flowers on 10cm stems above neat mounds of foliage.
Mossy stonecrop (Sedum acre ‘Golden Queen’) A dwarf succulent forming carpets of green foliage with yellow flowers in summer.
Juniper-leaved thrift (Armeria juniperifolia) An evergreen perennial which creates compact mats of needle-like foliage and has the typical pink thrift flowers in late spring.
Italian bellflower (Campanula garganica ‘Dickson’s Gold’) Starry blue flowers appear above low clumps of yellowish, heart-shaped leaves in summer.
Saxifrage ‘Hare Knoll Beauty’. Photograph: Alamy
Saxifrage (Saxifraga ‘Jenkinsiae’, ‘Hare Knoll Beauty’, ‘Cranbourne’ and ‘Gloria’) The saxifrages are some of the earliest to flower, at the end of February, with blooms in white, yellow and hot pink.
Campanula ‘Dickson’s Gold’. Photograph: Alamy
Cinquefoil (Potentilla eriocarpa) From the Himalayas, this sweet little grey-leaved beauty blooms yellow over a long season. Great for cracks and crevices.
Storksbill (Erodium x variabile ‘Roseum’) Low and spreading with geranium-like pink flowers and rounded, lobed leaves.
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New Zealand Plants and their Story
Perhaps a formal rockery, or a special alpine garden, may seem altogether too ambitious for a school-garden. Still, the New Zealand mountain-plants yield such instructive material for study, and are so beautiful or curious, that a few, at any rate, should be grown; and there is usually some shady corner that might be spared for these plants. Also, a good deal can be done in the way of providing a suitable growing-place by the aid of a few bricks or stones, especially if there be an abundant water-supply.
Of all forms of flower-gardening, this growing of alpine plants is the most fascinating. During recent years the alpine garden has become firmly established in Europe as an indispensable part of any garden of note. In scientific establishments, too, the cultivation of alpine plants is pursued with vigour. The new Botanic Gardens of Berlin have a great rockery, arranged on plant-geographical principles, to represent the different alpine floras of Europe. Some day, when we in New Zealand have what we ought to possess, a national botanic garden, it may there be possible to reproduce the different plant societies of New Zealand. The Royal Botanic Gardens of Edinburgh have the finest collection of alpine plants in Britain, and are specially rich in New Zealand species. Many of the Continental universities have their alpine gardens high in the Alps, where the effect of an alpine climate on the form and structure of plants can be studied.
As for growing New Zealand alpine plants, the method entirely depends upon the climate of the locality. At Invercargill, in many parts of Dunedin and its environs, on the west coast of the South Island, and probably at many places in the interior of the North Island, alpine plants can be grown with the greatest ease in the ordinary flower-border, any special construction, such as a rockery, being quite superfluous for many species. But in some parts of New Zealand, and in certain soils, it is quite otherwise. The grand secret of growing New Zealand “alpines” is to give them perfect drainage, a shady but quite open position, and plenty of water. Where the drainage is absolutely perfect, it is hardly possible to overdo the watering page 173
page 174in a dry climate. In a wet one the natural rainfall may be enough. To procure this good drainage, in many cases a rockery is useful (fig. 68). It is also a fact that some few plants which root deeply love to press their roots far between the stones; and, finally, a raised bed is advantageous for displaying the smaller plants. As for the rock, some kind that will crumble with the weather is the best; but bricks are far from being a bad substitute, although an ugly one. As well as stone, there must be plenty of light soil. Sweet, peaty soil is good; a foundation of small stones is also excellent. Each individual
Fig. 69.—Viola Cunninghamii, the common New Zealand Violet.
[Photo, J. Crosby-Smith.
plant should be allowed a fair proportion of soil. Small shrubs, planted here and there, are effective, giving both a natural appearance and affording shelter. In eastern Canterbury the nor’-wester is the bane of the alpine gardener. The sou’-wester does little harm, but the constant east wind is better blocked out. With management, nearly all the New Zealand alpine plants can be grown; but some are difficult to manage, even in the most favourable gardens. The following are some of the easier-grown of the page 175
Fig. 70.—Cotula pyrethrifolia, growing on a shingle-slip. Southern Alps, Westland.
[Photo, L. Cockayne.
page 176herbaceous plants: Ranunculus insignis, R. lobulatus, R. Enysii, Viola Cunninghamii (fig. 69), Oxalis magellanica, Geum parviflorun, Epilobium gracilipes, Myosotis australis, M. decora, Cotula pyrethrifolia (fig. 70), Raoulia australis, R. tenuicaulis, R. subsericea, Acaena microphylla, A. glabra, Ourisia macrophylla, Celmisia verbascifolia, C. rigida, C. Lindsayi, C. Mackaui, C. coriacea, C. spectabilis, Angelica Gingidium, Brachycome Sinclairii, Helichrysum bellidioides, Gnaphalium trinerve. The following are small, shrubby plants: Carmichaelia nana, C. Monroi, Veronica epacridea, V. loganioides, Rubus parvus, Veronica Gibbsii, Coprosma repens.
Any of the taller subalpine scrub plants can be used, and can be replaced by smaller specimens when they get too big. In fact, the plants to be made use of will depend so much on the size and situation of the alpine garden that hints regarding what to grow are not of much use. Moreover, the enthusiastic collector will bring home all sorts of plants, regardless of their capabilities, and the success of the alpine garden will be due entirely to his own energy, and to the knowledge he will acquire in the school of experience.
A garden of this kind is being established at the Cass, in the mountains of Canterbury, by Canterbury College (New Zealand University).
The beauty of Alpine Plants with the RHS Wisley team
I had been looking forward to our event at Wisley for some time – it was to be a unique opportunity to get behind the scenes with Cara Smith, leader of the Alpine House team, accompanied by Lucie, a team member.
After finding our way to Wisley through the Saharan dust cloud, and a quick cuppa, we made a party of twenty guests, some alpine enthusiasts, but generally all wanting to find out more. I consider ourselves incredibly lucky to have been in the Alpine House at this time of year, accompanied by such enthusiastic, passionate and knowledgeable guides.
We were inspired to try creating alpine environments in a variety of attractive ways – in imitation of the Crevice garden, built in 2011 by ZeeZee, a Czech landscaper who employs this method frequently in his native country where this style of gardening is very popular. Within each crevice, small micro climates are created for different types of plants, but it is very much trial and error to see what the possibilities are. The only maintenance required is watering, weeding and replanting where gaps appear. The Daphne in particular has been a nice surprise for the team – providing a good display and delicious scent.
Cara’s special area of interest are the South African flowers whilst Lucie had a wealth of knowledge about Hepatica’s – many of which have been donated to Wisley by a private collector – are rare and therefore especially valuable. (Lucie takes us to non-public access areas to see the valuable hepatica’s – one of which was recently stolen.)
It is always flattering for us when someone with the alpine plant authority and knowledge of Cara (on behalf of Wisley), says that she reserves the very best plants, at the height of their fabulousness, for the Alitex greenhouse (which is the Wisley Alpine house). They pick out the best looking plants from behind the scenes to display to the public – without doubt the plants we saw were all magnificent so it is amazing how selections are made!
It is not just about floral display either, leaves can provide a focal point of interest, be they marbled, hairy, tiny or the larger leaved plants typical of Japan. I liked the drama of this leaf grouping.
Top tips include: Control the water your alpine plants intake through their terracotta pots by removing them from their wet sand surround and soaking them thoroughly. Don’t rely on watering in situ as the water will leach by osmosis to the drier surrounding area.
No misting was necessary as alpine plants would develop fungal disease. The plants were kept at an optimum cool temperature of 5/6 degrees centigrade, replicating the harsh conditions of the Alps.
Learn more about Alpines from this dedicated book (Kew Books) recommended by Cara.
Thank you to the Alpine Team for a great day and to our guests for making the event so enjoyable.
Alpines suitable for troughs and containers.
We grow a very wide range of plants which are truly suitable for growing in troughs. If you are a novice you probably couldn’t do better than with one of our specially selected trough plant collections. Other containers are equally suitable but we simply refer to them as ‘troughs’ or ‘plants for troughs’. A web search for ‘planting alpine troughs’ or similar will yield a bounty of (generally) good advice. I list some links below that are worth reading and offer honest, reliable advice.
I will add a few basic tips – all containers must have drainage holes in the base. Use a good, soil-based compost. Yes, you can grow perfectly good plants in a the more common peat-based composts (or even peat substitutes) but it’s my opinion that nothing will ensure better chances of long-term success than incorporating some soil (or loam) in the compost. A good basic recipe is to select a John Innes compost (from any garden centre or diy store) and mix in a good amount of small grit – perhaps 1 part grit to 3 parts of pre-prepared John Innes. This will improve drainage but it will also make the container very heavy, so first place the container where it is to stay.
Another tip is to fill the container to the brim with compost mixture, even overfill it, mounding it slightly as you plant. Nothing looks worse than a loosely filled container where the compost (and plants) have settled a few inches below the rim of the container – it just looks wrong! Firm the compost around the edges as you fill the container. A carefully selected and placed stone or two often looks good as can broken slate arranged almost vertically or sloped at an angle. These offer different planting opportunities for some of the little gems.
After you have planted your trough, top it off with generous layer of grit or small gravel.
Feeding. The initial compost will contain enough nutrients to last the plants for the first season. Thereafter, only a light sprinkling of powdered fertiliser should be needed, once in spring and again in late June/July. Only use at half the rate recommended for other garden plants. A fertiliser containing more potash – high ‘K’ or fruit and flower feed – is ideal. Liquid feeding works well too – a liquid tomato fertiliser is ideal, but again, only at half-rate. This can be given perhaps every 3 or 4 weeks or so when watering during the growing season. The aim is just to keep the plants healthy and active in their limited volume of soil, not to encourage lush, rapid growth – hence the use of fertilisers at low rate only.
When compliling this list I have restricted it to those smaller, neater-growing alpines that will enjoy growing in a stone trough or similar container.
- Androsace – all of them. A. sempervivoides will form a mat and mound itself over an edge. The rest are more or less bun-shaped.
- Antennaria dioica ‘Minima’
- Armeria juniperifolia (pink) and ‘Alba’ (white), ‘A Little in the Red’.
- Aubrieta ‘Astolat’ – a neater and slower growing form with silver variegated foliage.
- Campanula – smaller ones like ‘Elizabeth Oliver’, Timsbury Perfection’, ‘Tubby’ and ‘Puck’.
- Delosperma – congestum and sutherlandii. Succulents enjoying hot, sunny places.
- Dianthus – many, especially D. alpinus, Joan’s Blood, Babi Lom, Berlin Snow, Inshriach Dazzler, La Bourboule Alba.
- Draba rigida imbricata
- Ectotropis – a succulent (formerly Delosperma ‘Sani Pass’), good, dark foliage and white flowers.
- Erysimum kotschyanum
- Gentiana saxosa – a classy late summer Gentian with white flowers. Evergreen.
- Globularia ‘Blue Bonnets’ – neat evergreen buns, pretty blue globe flowers.
- Lewisia – all. ‘Little Plum’ is highly recommended but all are good for troughs.
- Morisia monanthos – when we have it!
- Oxalis ‘Ione Hecker’ and ‘Waverley Hybrid’. Superb trough plants. Neat and ‘different’.
- Penstemon – dwarfer ones, especially P. ‘Microphyllus’
- Phlox – all the P. douglasii types and P. subulata ‘Snowflake’
- Potentilla nitida Rubra – classy solver-leafed plant and unusaul rosy pink flowers.
- Primula – all the dwarf ones, ‘Mrs J H Wilson’, ‘Dianne’, P. marginata ‘Prichard’s Variety’, P. warshenewskiana and others.
- Salix – esp. ‘Boydii’ – a shrub, but very slow and Salix reticulata.
- Saponaria ‘Bressingham’ and Saponaria x olivana.
- Saxifraga – almost all, especially silver encrusted, Sax. oppositifolias and the early flowerers like ‘Boston Spa’ and ‘Gold Dust’.
- Sedum – almost all but esp. the smaller types. Good if hot and dry.
- Sempervivum – every one of them. As above, good if hot and dry.
- Silene acaulis ‘Blush’ and ‘Frances’
- Thymus ‘Elfin’, possibly ‘Minor’ if more space.
- Veronica prostrata ‘Nana’
Links worth reading:
Several people have given their time freely to encourage and educate others on making troughs and growing alpine plants. Gardening people are some of the most generous people around, happily giving their time, knowledge (and often plants!) free for the benefit of others. Here are a few of the best sites I have come across, in no particular order.
Jan Tholhuijsen has made a remarkably informative video and e-book explaining how he makes his own troughs – from polystyrene boxes, but you would never guess!. It’s well worth reading and a rich source of additional information – and inspiration! Thank you, Jan.
Portraits of Alpine Plants is another wonderful website from a very experienced grower of alpine plants. Everything is covered – buying or making your own ‘stone’ sink (various methods), choosing plants, siting, compost – it’s a very good read. Although the site is some years old, the author’s knowledge and enthusiasm for plants is peerless.
Growing with Plants is a useful read and has lots of good photo’s to help you along the way. One minor word of caution – it is American, so some of the references may be lost on us and it’s written in a very informal style (not a criticism).
Ian Young from Aberdeen has excellent information on his Bulb Log
The Scottish Rock Garden Club forum has a specific topic on troughs with some amazing images for inspiration and some useful tips. It is fairly lengthy.
Silver leaved plants.
Several of the plants we offer have silver or grey leaves and nothing looks better in the sunshine. Silver is also the ideal neutral backdrop to all those colourful flowers. Most prefer a well-drained and sunny position.
- Artemisia schmidtiana ‘Nana’
- Cotula hispida
- Euryops acraeus
- Luzula ulophylla
- Ozothamnus ‘County Park Silver’
- Potentilla nitida ‘Rubra’
- Raoulia australis
- Saxifraga – many – cochlearis Minor, Silver Maid, Monarch, Whitehill, Doctor Clay, Frances Cade and others.
- Sempervivum ‘Boule de Neige’
- Tanacetum densum
- Thymus ‘Silver Posie’ and Silver Queen’
The Division of Alpine Plants
The purpose of the division is to gather a collection of mountain flora, suitable for cognitive and educational purposes, carrying out plant evaluation and scientific research.
The division includes 1145 woody and herbaceous plants with 964 species and 181 breeds belonging to 70 families. The collection is grown in a small rock-garden and is divided into several sections of different areas, where plants from Europe, Asia, American Cordillera and the Far East Region are cultivated. The most prevalent families of the collection are: aster (Asteraceae) with 106 species and breeds, stonecrop (Crassulaceae) (105 species), buttercup (Ranunculaceae) (95 species), cabbage (Brassicaceae) (62 species), bellflower (Campanulaceae) (50 species) and carnation (Caryophyllaceae) (71 species). The genera with the largest species include: breakstone (Saxifraga), gentian (Gentiana), bellflower (Campanula), stonecrop (Sedum) and primrose (Primula).
The origin of division’s plants
The majority of plants in the collection are grown from seeds brought from various botanical gardens around the world through seed exchange programme. Šiauliai University Botanical Garden collaborates with other botanical gardens with alpine plant collections from Austria, Italy, France, Switzerland, Germany, Czech Republic, Canada, Norway, Sweden and Russia. Most of world’s alpine botanical gardens located in mountain regions also add seeds, which are collected from wildlife habitats, to their seed catalogue. For the purpose of building a rich alpine plant collection we focus on obtaining seeds gathered from their natural habitats. The largest part of our collection contain European mountain flora. The plants are selected regarding their origin, ornamental traits, species abundance and useful properties. We also greatly appreciate plant collectors’ collaboration and contribution to our garden.
|Lewisia cotyledon||The Division of Alpine Plants 1||Pulsatilla|
The alpine plants of the division are grown in a rock-garden and hotbeds. The rock-garden is built on an artificial hill and covers 7.5 ares. Herbaceous mountain flora is influenced by changing climate conditions of vertical zonality as well as harsh growing conditions and, therefore, contains a large morphological variety with numerous tufted, evergreen, dwarf, rosette, thick-leaved, fluffy and leathery-leaved plants. Due to physical and geographical barriers, limiting the plant population, there are plenty of rare endemic species growing in the mountains. Consequently, specific ecological conditions, similar to the ones taking place in mountain regions, must be provided in order to successfully grow the majority of alpine species. Some species require chalky soil while others prefer more acidic environment. The humidity and lighting requirements differ as well. Some of the collection’s plants, including alpine species, are grown in hotbeds as they cannot survive the outdoor growing conditions in the garden.
Owing to their huge variety alpine plants are largely popular worldwide. There are many plant growers associations established in various countries uniting world’s numerous alpine plant growers and fans. Our division also contains a large collection of phenomenal species with their interesting ornamental properties and other unique traits, some of which are even mentioned in legends. Some of these species include:
Lion’s-foot (Leontopodium alpinum), also known as edelweiss, grows in European mountains, 1800–3000 m altitude, prefers chalky soil. Lion’s-foot is popular for its silver flowers and unusual appearance. The whole plant along with its flowers is covered in soft dense hair, which adds a greyish tone to the plant’s colour. Lion’s-foot is also widely known as a symbol of alpinism and as a national flower in some countries. According to legends, young men used to climb the mountains and look for edelweiss that they could present to their women as a proof of eternal love.
Yellow gentian (Gentiana lutea), commonly known as bitter root, gets its name from Illyrian king Gentius, who lived 500 BC and was the first one to treat people using gentian plant during the plague. The tallest gentians are prevalent in central and southern parts of Europe, where the flowering stems can occasionally grow up to 2 meters in height. It is believed that yellow gentian was the first gentian species to be grown in gardens. The rhizomes and roots of gentian plant contain tonic bitterness and are used as material for medicine.
Relic plants, belonging to ephedra genus, are conifer ancestors that have survived the ice age and are prevalent to this day. Ephedra minima (Ephedra monosperma) is one of the most beautiful species of ephedra genus. It is commonly found in areas of China and Siberia and prefers rocky slopes and dry places. This small, dense and robust shrub grows 20 cm in height and contains green stems with knotted nodes that resemble horsetail plants. Ephedra minima’s leaves possess some unusual traits. They are tiny, scaly and unable to perform photosynthesis. The plant contains bright red, succulent fruits, 6–9 mm in diameter, each holding only one seed. The seed is surrounded by a fleshy cone that becomes orange or red during maturity and has a resemblance to a berry. Ephedra is one of the world’s oldest known medicinal plants, although it is currently banned in many countries due to the reports of its serious side effects. Ephedrine extract is used in the Traditional Chinese and Japanese Medicine. A tea, made from dried ephedra seeds mixed with white tea or herbs, is made in Mongolia.
|Leontopodium alpinum||Gentiana lutea||Ephedra monosperma|
Long-leaved whorl flower (Morina longifolia) is naturally found in Himalayan Mountains, 3000–4000 m altitude. The Latin name “morina” was given in honour of a French botanist Louis Morin. Long-leaved whorl flower has been grown in gardens since 1839. The flowers of the plant are exceptionally ornamental. Small white blossoms form gorgeous inflorescences that grow out of plant’s whorl. After the pollination the blossoms start getting a red shade and eventually become completely red. Plant’s stem, leaves and flowers were used in Tibet medicine for their sweetish taste and digestion-enhancing properties. Upon touching or rubbing, the leaves and flowers give out a pleasant citrus smell. The scent of flowers particularly intensifies at night. Long-leaved whorl’s roots contain essential oil, which is used for incense production. It is believed that the scent of long-leaved whorl flower repels garden pests.
Azorella (Azorella trifurcata), commonly found in South America (Chile, Argentina), is one of the most effective carpeting plants. It grows up to 10 cm in height and forms a rigid green tufted “carpet”. Azorella has small yellow flowers, which bloom during the months of June and July. The plant prefers direct sunlight and spreads vegetatively to retain heat. Azorella is grown in light, sandy soil, contains edible roots.
Alpine pink (Dianthus erinaceus ssp. alpinus) is common in Anatolian peninsula and Turkish mountains. The plant expands forming a typical ornate, cushion-like shape. It contains narrow, lanceolate greyish evergreen leaves. Alpine pink grows short, only 10–15 cm in height, however it spreads widely, filling up large areas. Its flowers are not abundant, blooming with several small pink blossoms between leaves. Alpine pink is an ideal plant for warm sunny areas and dry rock-gardens. Alpine pink plants tend to grow slowly, are durable and dislike excess moisture.
|Azorella trifurcata||Morina longifolia||Dianthus erinaceus ssp. alpinus|
The blooming season
Alpine plants become active in early spring and some plants start blooming at the end of March, when the garden is less frequently visited. However, the peak bloom does not start until June–July. Although the flowering decreases during the middle of the summer, there are still various beautiful dense cushion plants in the rock-garden to gaze upon. The plants’ shapes and foliage variety are as beautiful as their flowers. As the majority of division’s plants are evergreen the rock-garden can also be visited in autumn for a fascinating view of plants with diverse colours.
The idea to create an alpine garden was proposed 17 years ago by a former director of Šiauliai Botanical Garden prof. Vida Motiekaitytė. In the year 2000 a rock-garden was started on an artificial hill, first stones were laid and, a year later, first seedlings were planted. In 2001 the establishment of alpine plants’ collection was entrusted to a botanist Rimanta Vainorienė—a new employee at that time.
Private individuals have supported the development of rock-garden over the years by donating various materials: stones, dolomite, peat, sand. Valuable plants are annually donated by our friends—Latvian flower farm “Bērziņi“. Šiauliai Botanical Garden is collaborating with collectors, horticulturists: Genovaitė Pociūlienė, Rasa Miceikienė, Meilutė Mociškytė, Algirdas Gražys and a volunteer photographer Romualdas Struoga.
The division is administrated by a junior researcher PhD Rimanta Vainorienė, tel. (8 41) 553 934, e-mail: [email protected]
|Helleborus||The Division of Alpine Plants 3||DSC|
|Saxifraga||The Division of Alpine Plants 2||Primula|
|Gentiana||The Division of Alpine Plants 4||Gentiana|
Each of the plants shown have three main, special features that allow them to survive in the Alpine Tundra. The first feature that all plants have is an anti-freeze chemical. The only reason that the plants don’t freeze and die is because of a chemical produced to coat and protect the plants from the low temperatures. The next feature that the plants obtain is a specialized root system. Instead of the roots growing vertically downward, they spread and grow horizontally. This adaptation is crucial to the survival of these plants because if the roots grow vertically downward, they would reach the permafrost soil. This would cause the plants to die because of water loss from the frozen soil. The last adaptation the tundra plants have is the transpiration limitation. Transpiration is the evaporation of water from plant leaves, which can cause plants to dry out due to water loss. Plants need all the water they can get, especially in the cold, dry tundra! So, to limit the water loss, all of the plants obtain leathery leaves that have waxy, hairy surfaces to keep the moisture in the plants. With the chemical anti-freeze adaptation, special root system, and transpiration limitation, plants in the tundra region are able to survive.
10 great plants for a living roof
Rooftop gardens keep your abode cool in summer, add a layer of insulation in winter and create funky, fragrant, butterfly- and hummingbird-filled hanging gardens throughout the year. In the process, they help to power down energy consumption and reduce the urban heat island effect; the heat generated from urban rooftops and parking lots that makes our cities unbearably hot. Green roof companies are sprouting up all over the place to help you make the transition, but installing a green roof is also a feasible project for a do-it-yourselfer. Even if you don’t have the time, money or technical wherewithal to give your entire home a green roof, you can start by trying it out on a small scale: a gazebo, shed roof, doghouse, or even a tiny birdhouse can be converted.
Rooftops are tough place for plants: they’re vulnerable to intense heat, cold, wind and drought, plus they can’t support a lot of weight, so the plants need to grow in just a few inches of soil (actually, ultra-lightweight soilless growing mediums are typically used). Thus, it’s plants that grow naturally on desert cliffs, alpine crags, and other such inhospitable places that are used for green roofs. Fortunately, these include many truly stunning species—some exquisitely beautiful, others absolutely bizarre and even a few that are edible or otherwise useful. Green roof plants fall into four general categories:
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These are the mainstays of any green roof and should form the bulk of the planting, unless provisions are made for the roof to support soil deeper than the 3 to 4 inches that is typical. These tiny succulents thrive with virtually no water or soil. They are available in a kaleidoscope of colors, giving a broad palette with which to design your living roof.
Sedum spp. Also known as stonecrop, because the succulent foliage resembles smooth, polished stone, sedums are the royalty of living roof plants. There are literally hundreds of varieties, found growing in cliff-side cracks and crannies around the world and were the first species employed in the green roof industry. With so many distinctly colored varieties available, you can paint a beautiful picture on your roof.
Sempervivum spp. Called houseleeks (because they were used as a traditional Scandinavian rooftop plant) by some and hen and chicks by others (the mature rosettes “give birth” to tiny replicas of themselves as they spread), sempervivum means “evergreen” in Latin, indicating that your roof will be attractive year-round with this type of succulent. Like sedums, they stay low to the ground and come in many colors.
Delosperma spp.are spreading succulents grown for their daisy-like flowers, which bloom throughout the growing season. There are white, yellow, red and purple varieties and most have the habit of changing their shade of color as the flowers fade, creating a monochromatic effect
Aenoium arboreum is a variety of houseleek that grows as a tiny tree (usually less than two feet tall) that looks like it would be more at home on Mars than planet Earth. It’s not a spreading ground cover like the other succulents in the list, but it can create a bit of vertical variation in your roof garden. The variety Zwartkop or Schwartzkopf (black head, in Dutch or German) will create plenty of interest with its color as well—it’s such a deep purple that it’s almost black.
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Most grasses would fail on a living roof, unless they were watered constantly in the summer. However, there are a few that have what it takes to withstand the conditions. To be honest, most green roof grasses are not considered as such from a botanical perspective, and are more accurately termed “grass-like plants”. Like the succulents, they are good for covering a lot of territory and create a pleasing contrast when combined with succulents. Many seed themselves, making your rooftop garden a self-replenishing landscape.
Armeria maritima is not at all related to what grows in lawns, but the foliage appears as a tidy green clump of grass. In nature, it grows in ocean-side cliffs and dunes (hence the name maritima), making it well adapted to rooftop conditions—especially those by the sea. It is also called sea thrift and, unlike any grass, it is crowned with pink or purple flowers in summer.
Carex nigra is technically considered a sedge and is often used on living roofs, because its roots require less soil than most other grasses, or grass-like, plants.
These are used more sparingly and benefit from a bit deeper soil than the other species listed here. This can be accomplished by mounding the planting medium here and there to create little wildflower hummocks. Use them for a taller accent in sporadic locations in your living roof design.
Aster alpinus is an aster from alpine regions, meaning it is no stranger to intense weather and thin soil. Nonetheless, it produces brilliant sprays of deeply saturated purple flowers with yellow button centers, which attract hordes of butterflies.
Achillea millefolium is commonly known as yarrow; a wildflower that, unlike asters, will spread across the surface of your living roof as a ground cover. This powerful medicinal plant has ferny, aromatic foliage and tall flower stalks capped with broad concave blossoms which make great landing pads for butterflies. Yarrow has the added benefit of tolerating light foot traffic.
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This is where a living roof crosses over to become an herb garden. Many of the most common culinary herbs happen to grow in dry, rocky places, making them ideal candidates for a green roof. The varieties listed here are low-growing, wide-spreading groundcovers; the other key trait for a living rooftop carpet.
Thymus vulgaris is the standard garden variety of thyme that creeps along just a few inches tall and, like yarrow, can tolerate being walked upon. It makes a luxurious aromatherapy bed for rooftop sunbathing and, of course, can be harvested on demand for the kitchen.
Origanum vulgare is common oregano. Like thyme, it is native to the rocky hills of the Mediterranean basin and it can bring that special flavor to your rooftop if you choose to plant it. It’s also a ground cover, growing 4 to 6 inches tall.
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