In principle, it is very easy to find hardy rock garden plants. All plants that come from alpine areas and have established themselves there are generally naturally used to stony and dry soils and the blazing sun. At higher altitudes, the mostly low-growing plants are not protected by the shade of larger trees and are exposed to wind and weather. Species that are native to the European low mountain ranges and the high altitudes of the high mountains can also tolerate extreme temperatures without harm, which is why they are ideal winter-hardy rock garden plants that do not even need protection from frost.
Hardy trees
You can't go wrong with softwoods in a rock garden. Conifers preferably come from northern regions or are native to altitudes where there are severe frosts in winter. In the rock garden, it is primarily the low-growing or columnar conifers that are used. All of the trees listed tolerate full sun locations.
Miniconifers:
- Flat-spherical mini cypress (Chamaecyparis pisifera 'Sungold')
- Hinoki Cypress (Chamaecyparis obtusa 'Nana Gracilis')
- Creeping juniper (Juniperus procumbens 'Nana')
- Caucasus variegated juniper (Juniperus squamata 'Floreant')
- Sawara Cypress (Chamaecyparis pisifera 'Nana')
- Dwarf balsam fir (Abies balsamea 'Nana')
- Dwarf Colorado fir (Abies concolor 'Compacta')
- Dwarf black pine (Pinus nigra 'Green Tower')
- Dwarf pines (Pinus mugo like 'Jacobsen', 'Alpenzwerg' or 'Mops')
Columnar, hardy conifers:
- Hanging blue cedar (Cedrus libani 'Glauca Pendula')
- Mediterranean cypress (Cupressus sempervirens 'Stricta')
- Columnar juniper (Juniperus communis 'Sentinel')
- Rocket juniper (Juniperus scopulorum 'Blue Arrow') also called Green Arrow
- Dwarf mussel cypress (Chamaecyparis 'Nana Gracilis')
Hardy Shrubs
Hardy shrubs provide variety in the rock garden. Many of them are also evergreen, meaning they retain their green foliage even in winter. Perfect for accents in a dreary garden.
- Alpine daphne (Daphne alpina): sun to partial shade, 40 cm high, white flowers in May/June
- Blue rue (Perovskia abrotanoides): height 50 to 100 cm
- Rock Bluepot (Moltkia petraea): full sun, blue flowers in June/July
- Rock Daphne (Daphne petrae): flowering ground cover shrub, height about 10 cm
- Japanese yellow-leaved spiraea (Spiraea japonica 'Golden Little Princess'): sun to partial shade, up to 40 cm high, pink flowers in May/June
- Small-leaved boxwood (Buxus microphylla var. koreana): sun to partial shade, 30 cm high
- Lavender (Lavandula): growth height 30 to 80 cm (depending on the variety)
- Laurel loquat (Photinia) like Photinia fraseri 'Red Robin' (purple loquat)
- Mongolian clematis (Clematis tangutica): full sun, up to 3 m high, climbing plant, yellow flowers in June/August
- Purple-leaved sage (Salvia officinalis purpurascens): full sun to partial shade, up to 40 cm high, blue-purple flowers in June/July
- Spit willow (Salix hastata 'Verhanii'): full sun, height up to 40 cm, catkins in April
- Dwarf lilac (Syringa meyeri): full sun, up to 1 m high, light purple flowers in April/May
- Dwarf Green Knotweed (Muehlenbeckia axillaris 'Nana'): Sun to partial shade, yellow flowers from May to July
Tip:
The evergreen azaleas and rhododendrons can also be planted in the rock garden. However, they need acidic soil and a little more moisture in summer.
Frost-hardy cushion plants and ground cover for the rock garden
These plants partially retreat into the ground in autumn and then sprout again in spring. Some species impress with their beautiful flowers, while in others it is the foliage that is an eye-catcher, sometimes even all year round. Alpine plants of all kinds prove to be extremely frost-resistant and are therefore perfectly winter-hardy rock garden plants.
- Perennial ice plant (Delosperma 'Brotas'): orange flowers from June to September
- Blue cushion (Aubrieta x cultorum): available in different types, also for the full sun, flowering in April/May
- Bristly chickweed (Arenaria ledebouriana): white flowers from May to June
- Rock pink (Dianthus arpadianus ssp. pumilo): pink flowers from April to May
- ethhens (Sedum species): flowers from May to August, many wintergreen species
- Cinquefoil (Potentilla species): mostly yellow flowers from April to August
- Lilac cushion (Leptinella squalida): dwarf cushion with attractive leaf color (various colors)
- Common bitterroot (Lewisia cotyledon): rosette-like plant with flowers in May to June, succulent, evergreen
- Carnation (Armeria maritima): Cushion carnation for the blazing sun, different colors
- Fringed sand carnation (Dianthus arenarius): full sun, white flowers from July to October
- Yellow-green-leaved goose cress (Arabis ferdinandi-coburgi 'Old Gold'): yellow-green variegated foliage, ornamental foliage plant, white flowers in May
- Houseleek (Sempervivum): rosette-shaped, succulent ground cover, well drought-resistant
- Houseleek Man's Shield (Andresace sempervivoides): sun to partial shade, pink-red flowers in May/June, evergreen
- Autumn gentian (Gentiana sino-ornata 'White Mountain'): typical dark blue flowers in autumn
- Heart-leaved creeping globe flower (Globularia cordifolia): light blue flowers from May to July
- Cat's paw (Antennaria dioica): white-pink flowers in May/June
- Spoonwort dwarf bellflowers (Campanula cochleariifolia): flowers available in different colors, blooming in June to August
- May Carpet Veronica (Veronica prostrata): light blue or white flowers in May/June
- Wallflower (cymbalaria, Cymbalaria muralis): white or light purple flowers
- Moss stonewort (Sax (da) arendsii hybrids): pink, red or white flowers in May to June
- Austrian Miere (Minuartia austriaca): white flowers in June to August
- Pentecost carnation (Diantus grantianopolitanus): various species with flowers in May to July
- Cushion phlox (Phlox subulata): wonderfully flowering cushion perennial, blooms from June to August
- Red-leaved carnation (Armeria rubra): Special feature among the carnations with pink flowers and red foliage
- Siberian skullcap (Scutellaria scordiifolia): blue-violet flowers from May to August
- Silver-green prickly nut (Acaena magellanica): silvery leaves, ornamental foliage plant
- Taurus dwarf goose cress (Arabis androsacea): small white flowers in June
- Carpet Gypsophila (Gypsophila repens): white veils of flowers from May to August
- Carpet Veronica (Veronica 'Lapis Lazuli'): blue flowers from May to June
- Thyme (thymus species): the hardy varieties are Thymus praecox (early flowering thyme), Tyhmus serpyllum (sand, cushion and snow thyme), Thymus vulgaris (spiced thyme)
- White mountain chamomile (Anthemis carpatica 'Carpathian Snow'): white flowers in May
- White Caucasian goose cress (Arabis caucasia 'Snowhood'): white flowers from April to May
- White silverwort (Dryas octopetala): silvery-white foliage, ornamental foliage plant
- Winter scarlet moss (Sax (da) muscoides): white flowers from May to June
- Dwarf rockflowers (Draba species): flowering dwarf cushions with a height of 2-4 cm
- Dwarf cushion phlox (Phlox douglasii): numerous flowers
Perennials for full sun areas in the rock garden
Perennials not only thrive in beds, but also thrive in rock gardens. Provided you choose the right varieties. Most of the time, large parts of the rock garden are in the blazing sun or at least in the shade for a very short time. The following hardy rock garden plants are suitable for these places:
- Alpine aster (Aster alpinus species): low-growing aster species
- Alpine balsam (Erinus alpinus): long blooming (April to July)
- Alpine edelweiss (Leontopodium alpinum): 15-20 cm height, calcareous soil
- Alpine silvercoat (Alchemilla alpina or hoppeana): small perennial, light yellow flowers from June to August
- Altai anemone (Anemone altaica): 20 cm high, white flowers in June/July
- Arnica (Arnica montana): 25 cm high, yellow flowers from May to July
- Sedum (Sedum species): also called stonecrop, many tall and short species
- Felty hornwort (Cerastium tomentosum): silvery-white foliage, white flowers in May to June
- Spring Adonis rose (Adonis vernalis): yellow flowers in April/May, 15 cm high
- Yellow mountain monkshood (Aconitum lycoctomum ssp. vulparia): light yellow flowers in June to August, height up to 80 cm
- Yellow candle lily (Asphodeline lutea): 25 cm high, yellow flowers in May/June
- Shining silver rue (Artemisia caucasica var. nitida): small perennial with silvery leaves
- Goldspur Columbine (Aquilegia chrysantha 'Yellow Quenn'): 15 cm high, yellow flowers in May/June
- Wall alyssum (Alyssum saxatile compactum): up to 20 cm high, deep yellow flowers in April/May
- Midday flower (Delosperma): low-growing, very colorful flowers
- Pearl Paw (Anaphalis margaritacea 'Neuschnee'): white flowers from June to September, height 50 cm
- Röhrenstern (Amsonia angustifolia 'Blue Ice'): light blue flowers from May to July, height 40 cm
- Silver-leaved chamomile daisy (Anthemis marschalliana): 20 cm high, yellow flowers from June to August
- Silver thistle (Carlina acaulis): perennial, herbaceous plant with growth heights of up to 50 cm
- silver sheaf (Achillea ageratifolia species): small perennial with white flowers in May/June
- Stone purse (Aethionema armenum species): pink flower, height 10-25 cm depending on the species
- White Günsel (Ajuga reptans 'Alba'): small perennial up to 5 cm high, white flowers in June to August
- Spurge (Euphorbia): the upper leaves are colored
- Dwarf pearl yarrow (Achillea ptarmica 'Nana Compacta'): 25 cm height, white flowers from June to September
Winter-hardy rock garden plants for shaded areas
Of course, rock gardens don't always consist of very sunny areas. That's why a few hardy rock garden plants must be planned for shady or semi-shady areas. Of course, there are also cool, shady places in the mountains whose natural flora thrives on little light. That's why hardy rock garden plants can also be found here. Condition: The moisture in the ground must be able to drain away quickly.
- Rock plate (Ramonda myconi): purple flowers
- Gold droplets (Chiastophyllum oppositifolium): tall, yellow flower spikes in June/July, slightly overhanging
- Haberlea species (Haberlea rhodopensis): bluish flowers with deep throat
- Globular flower (Globularia repens 'Pygmaea'): purple umbrella flowers, very flat growing
- Wall Rue (Asplenium ruta-muraria): for rock crevices and walls
- Moss saxifrage (Saxifraga x arendsii): delicate flower bowls in April and May
- Porcelain flowers (Saxifraga x urbium): pale pink, flower stalks up to 30 cm high
- Storksbill (Geranium): undemanding flowering plant with purple flowers
- Striped fern (Asplenium trichomanes): particularly suitable for dry stone walls
- Dwarf Columbine (Aquilegia flabellata): purple-white, bell-shaped flower
- Dwarf thrush (Armeria juniperifolia): looks almost like moss, flowers pink
Conclusion
Anyone who thinks that there isn't much choice of frost-resistant plants for a rock garden will be proven wrong: the variety is almost unbelievable. However, hardy rock garden plants are usually low-growing specimens. They are extremely robust and can survive long winters and cold winds without damage. Only soil that is too moist in the cold season will harm the hardy rock garden plants.
