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Tuesday, August 30, 2011

Autumn Gentian

Autumn Gentian

One of our favorite fall flowering perennials is the Autumn Gentian, Gentiana sino-ornata.  It forms a low mat of rooting stems with grassy foliage from which upward facing, trumpet shaped flowers open in late summer to early fall.

Autumn Gentian flowers most commonly occur in alluring shades of blue from sky blue to a deep marine blue.  They are generally palest at the base and often have streaks and spots.  Color variations occasionally occur in seed grown plants and we offer two additional selections as Wild Ginger Farm introductions.

Gentiana sino-ornata 'Moonlight'

Gentiana sino-ornata ‘Moonlight’ has vigorous bright green foliage and creamy white flowers.  It brightens up the garden in the fading light of fall.

Gentiana sino-ornata 'Stardust'
 Gentiana sino-ornata ‘Stardust’ is a striking Autumn Gentian dusted with tiny blue spots on a white background, creating the impression of a blue and white striped flower.

The solitary flowers often form showy clusters
 The Autumn Gentian is native to grassy slopes, meadows and forests in the mountains of SW China.  It requires well-drained, moderately fertile, acidic soil and regular water. As with many mountain plants, it is not a heat lover so it needs good light but some protection from the strongest sun.   It is reported to be quite cold hardy to -30 degrees F or lower. 

The Autumn Gentian growing in a propagation flat
 The Autumn Gentian makes a delightful addition to the open woodland garden, rock garden, trough or other well drained-container where it brightens the late season with its charming and beautiful flowers.

Tuesday, August 9, 2011

Saturday Class "Plant a Succulent Container

Lewisia longipetala hybrid

Summer is the perfect time to enjoy drought tolerant and easy to grow succulent plants and we invite you to join us this Saturday, August 13th for a class entitled “Plant a Succulent Container”.  You can bring your own pot or buy one here.  We will provide potting soil, 4 plants and accent rocks.  The fee for this class is $15.  Sign up by phone or email.

Hens and Chicks make great container plants

Sedum makinoi 'Variegatum'

Extremely drought tolerant Sedum ellacombianum

Small scale sedum species grouped in a container

Lewisia cotyledon is an easy to grow potted plant

Lewisia pymaea in full flower

Bergeranthus jamesii, a South African succulent
A mixed succulent trough

We hope you can make it to the class.  
Our summer open hours are Friday, Saturday and Sunday from 10 to 4.  

Wednesday, August 3, 2011

Tufa - The ultimate crevice rock

Tufa is a porous limestone rock useful in growing many alpine and lime loving plants.  Not to be confused with hypertufa, a cement-based imitation used to create troughs and other lightweight containers, authentic tufa is a calcium carbonate mineral precipitate that occurs around lime rich bodies of water.  We recently obtained a supply of tufa from the headwaters of the Columbia River.  The mineral composition and general quality of tufa deposits varies and this particular deposit is quite attractive with high porosity and a golden color.

One of the most important features of tufa is its ability to absorb and hold water like a sponge. This is an advantage when plants are planted near or even in the rock where water is released slowly over time.  Plants remain evenly moist and are cooled by slow, steady evaporation.  Even on a warm day, the surface of the tufa is noticeably cool to the touch.  This prevents heat stress at the root zone of alpine plants and keeps them healthy and growing during warm weather.

The possibilities for using tufa are limited only your imagination.  Tufa can be used in troughs, in specially designed crevice gardens and also in the open rock garden. We recently created a crevice garden exclusively with tufa.  We maximized the tufa surface area by placing the rocks upright and packing them tightly together.  We then planted in the crevices and also in holes drilled directly into the rock.

Tufa can also be planted as specimen rocks.  Using a 3/8” to 1” masonry bit, holes can be drilled into the tufa and small plants can be tucked into the voids.  Over time the roots penetrate into the rock and become firmly established.  The low nutrient environment ensures the plants maintain their characteristic compact forms.

Plants suitable for use with tufa include those from limestone habitats and many others that originate in low fertility, mineral rich soils.  Acid loving plants including Ericaceous and woodland plants will not grow well and should be avoided.

Plants that thrive in tufa include many encrusted and cushion saxifrages, Auriculastrum primulas such as Primula marginata, P. allionii, P. auricula and hybrids, certain Campanula and Draba species as well as Ramonda and Mediterranean plants such Aethionema schistosum and Alyssum stribyrni.  We are experimenting with Western alpine plants including Telesonix, Astragalus,  Antennaria, Arenaria, Eriophyllum and Heuchera to determine their suitability for growing in and around tufa. 

We invite you to explore the possibilities for using tufa in alpine gardening.  Tufa of various sizes is now available for sale at the nursery and smaller sizes will be available soon in our mail order catalog.

For more information about working with tufa, we have posted two how-to pages on our website