Arctostaphylos

[Robert]

There are 4 to 6 species of Arctostaphylos or Manzanita native to our region of California. A. nevadensis (Pinemat Manzanita), A.  patula (Greenleaf Manzanita), A. viscida (Whiteleaf Manzanita), and A. myrtifolia (Ione Manzanita) are species I’ve studied locally in the field. A. manzanita is listed in our area, however I’ve never found it locally. I have observed it in Tehama and Shasta counties about 150 miles to the north. Also there are natural hybrids between A. patula and A. viscida in our region.

Checking the catalog of our local premier native plant nursery I found 18 species and varieties listed. There are over 100 species and subspecies native to California as well as many named varieties. Certainly much to consider!




Arctostaphylos uva-ursi – not much to discuss. Well known, long cultivated and native through a large part of the northern hemisphere. I’ve observed this species in it native environment in the coastal sand dunes on the Oregon Coast as well as on the eastern slopes of the Cascade Range in South Central Oregon. The plant pictured I gathered as a cutting from a nice plant near Chiloquin, Oregon. A region also noted for its trophy rainbow trout for those that might be interested.



Arctostaphylos ‘Emerald Carpet’

Propagated by the millions here in California. Widely used in commercial landscapes – it is low and spreading, however tall enough to discourage weed growth. Established plants are xeric but can still tolerate summer irrigation in well drained soil.



Arctostaphylos ‘Sunset’

I’ve grown this variety for about 35 years. It grows about 1 meter in height, has beautiful bark as with many Manzanita species. The new growth in the spring is a beautiful copper color. The plant pictured is in landscaped area with a poor draining clay soil that also gets some irrigation during the summer. Over the years the plants has slowly moved and adjusted itself to a new location about .5 meters from its original site to location where it now thrives. Intelligent!

More later….

[Robert]

Arctostaphylos densiflora ‘Howard McMinn’ has grown in the garden for about 35 years too.



This pair grows with completely xeric conditions during the summer. It is given no additional irrigation and thrives. However, the species is also tolerant of summer irrigation with good soil drainage.

It blooms heavily with white flowers during the winter and the older bark is very attractive.

There are other named varieties of this species.



Arctostaphylos manzanita ‘Bill Letcher’ was given to me as unrooted cuttings by Mr. Bill Letcher. He found this plant somewhere in the Mount Shasta area of far north central California.



It has the deepest pink flowers of any manzanita that I have seen. The plant pictured is about 25 years old and is still very small and slow growing. The species generally grows quite large. It would be good if I propagated this variety and tested it in some other locations around the farm to see how it grows.

Do not try looking it up. The cultivar name is a de facto name that I have given it. It only grows at the farm here, something I hope to change.

I’ll have more later and hope to share information on propagation. Propagation by seed can be tricky.  I do have some empirical knowledge I would like to pass on.

[Hoy]

Two of my favorite shrubs here in Norway are Arctostaphylos uva-ursi and A. alpinus, the only ones of its kind here.

The flowers are nice on both of them and the fall colour is excellent on A. alpinus.

I have been aware of the American species but never had chance to see any!

[Robert]

Trond,

Yes, the fall color of A. alpinus is excellent! I like it a lot! In what part of Norway does A. alpinus grow? It would be interesting to try it here, however it may not like our summer heat.

Thank you so much for sharing the photographs!

Here is another California native Manzinita.



Acrtostaphylos patula

This at 4,880 ft. (approx. 1,485 meters) the transition zone between A. patula and A. viscida. Both species are found in this area with many plants having characteristics of both species.



The dark chestnut bark is beautiful.



A closeup of the bark.

[Robert]

A few photographs of the high elevation Manzanitas.



Here one can see A. nevadensis creeping over the ground. It can spread around a bit however seems suitable to a large rock garden. It grows in very rocky gravelly soil - i.e. needs excellent drainage. Other than that it is easy-to-grow around here.



A. nevadensis creeping over and around rocks - something it likes to do.



A. nevadensis - Beautiful bark on older plants.



A. patula - The decumbent form growing at high elevation. In forest opening A. patula grows taller and more upright. In exposed areas it tries to hug the ground. At the higher elevations there is considerable snow and strong winds. I have young plants of both forms - it will be interesting to see if they grow true to form in a protected garden and at a much lower elevation.

[ian mcdonald]

Does anyone know of a supplier of Arctostaphylos alpinus in the UK?

[Hoy]

Trond,

Yes, the fall color of A. alpinus is excellent! I like it a lot! In what part of Norway does A. alpinus grow? It would be interesting to try it here, however it may not like our summer heat.

Thank you so much for sharing the photographs!

Here is another California native Manzinita.


Acrtostaphylos patula

This at 4,880 ft. (approx. 1,485 meters) the transition zone between A. patula and A. viscida. Both species are found in this area with many plants having characteristics of both species.


The dark chestnut bark is beautiful.


A closeup of the bark.

Robert,
A. alpinus grows from sea level and up into the mountains. However it is rare at lower altitude and it dislike competition and shade from taller shrubs etc. If you want to try it I can look for seed but I think it is too late this year. Cuttings are also an option but I don't know whether it is possible to send it to USA?

I like the look of the bark - both of patula and nevadensis! I think A. uva-ursi have a similar bark but the stems are much thinner and always groundhugging.

[Robert]

Trond,

I have a very dear friend that lives in Alesund. Does Arctostaphylos alpinus grow near sea level in this area or is this farther north?

Thank you for some of its cultural requirements.

[Hoy]

Trond,

I have a very dear friend that lives in Alesund. Does Arctostaphylos alpinus grow near sea level in this area or is this farther north?

Thank you for some of its cultural requirements.

A. alpinus grows at sea level even here where I live at 66N near the small city of Haugesund far south of Ålesund. And like Manzanita it only grows where it has perfect drainage (but it can take a lot of rain). Here it grows in very shallow soil and crevices in bare rock. In the mountains it likes the sandy and stony ridges.

[Robert]

Trond,

A very long weekend for me at the farmers' market!

Thanks for the information on A. alpinus. I can get away with growing some of our high elevation California alpines such as Cassiope mertensiana, and Vacinium ceaspitosa, down the mountain, here at the farm. It would be interesting to see if I would have success with A. alpinus.

[Robert]

At the farm I never plant Arctostaphylos viscida - the birds do it for me.

This got me thinking about propagation of Arctostaphylos from seed. Around here, the general idea is that fire is necessary to scar and soften the rock hard seed coat before germination can occur. There has not been a fire on the place for many years and clearly a bird's digestive tract is enough to do the job of etching the seed coat. Around the countryside, I've seen how the digestive tracts of other wild animals has the same effect on this hard seed coat.

Using these ideas I now soak Arctostaphylos seed in digestive enzymes (with HCL) for about 2 days as a pre treatment before cold stratification for about 2-3 months. The system seems to work - at least as well as fire treatment - and I don't have to burn pine needles over the freshly planted seed.

I think that an additional gibberellic acid treatment, before cold stratification, would be helpful too, but I have not done this yet.

Generally, I have found rooting cutting easy. Hard wood cuttings from early summer through the winter give me consistent results.

[Hoy]

At the farm I never plant Arctostaphylos viscida - the birds do it for me.

This got me thinking about propagation of Arctostaphylos from seed. Around here, the general idea is that fire is necessary to scar and soften the rock hard seed coat before germination can occur. There has not been a fire on the place for many years and clearly a bird's digestive tract is enough to do the job of etching the seed coat. Around the countryside, I've seen how the digestive tracts of other wild animals has the same effect on this hard seed coat.
.....

Interesting but I am not astonished. Most berries are usually eaten by birds and I think berries and birds have coevolved. Food for the birds and dispersal for the plant.
The sap in the berry contains anti germinating substances which have to be removed/broken down before germination can occur and the seed coat has to be weakened either mechanically or chemically. To stand the conditions in the bird's gizzard the seeds have to be very tough!

Seeds from plants like Taxus, Cotoneaster, Prunus and many others germinate almost without exception in bird droppings or under trees where birds roost.
I have also observed that if the pulp of the seed rots the seedcoat is weakened enough and the seed germinates. As long as the pulp is fresh it inhibits germination.

[Robert]

Trond,

When saving vegetable seed here at the farm we always ferment the fleshy fruits of tomato, etc. Not only does is make seed cleaning easier but it also kills off many disease organisms. Another good reason to ferment fleshy fruits before planting the seed.

In California some species do need fire for seed germination. Pinus attenuata (Knobcone Pine) comes to mind. The pine cones will not open and release the seed without the heat of fire. I've seen trees where branches have overgrown the pine cones still clinging to the branch unopened.

[Hoy]

Robert,

Just so! I learnt to let the tomatoes ferment before storing and sowing the seeds from an old gardener at the university where I studied many years ago.

I know that some species like pines need fire for germination but certainly not plants with berries?