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Plants, Ecosystems, Climate – Northern California

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Late autumn weather has settled into our region of California. There has been dense fog in the Central Valley with little or no clearing during the day. Above the inversion layer, skies have been clear with well above average temperatures.

Precipitation amounts during the first 2 weeks of November have been below average. In a slow process, I am gradually developing a climatic forecasting model that I can run on my laptop computer. It might seem an unrealistic endeavor, however I am enjoying every aspect. Based on statistical-type modeling, the current dry pattern appears that it will persist for the next month or more. Temperatures in November have been above average. This trend looks like it will continue for the next week. Beyond, for the next month temperatures could go in either direction. There are mixed and contrasting indications in both the statistical- and dynamic-type modeling.

Either way, it is obvious that both the daily and long-term climatic trends have a profound impact on plants, in our Sacramento garden, native ecosystems, and all managed and unmanaged ecosystems as a whole.

I have started seeding out species that need some degree of winter chilling (vernalization) to germinate properly. With climate change, it is questionable if there are adequate chilling hours for some species during the winter in our Sacramento garden. Epigenetic changes can sometimes take place that alter a seed’s response to chilling hours, allowing germination with fewer chilling hours and allowing these characteristics to be passed on to the progeny without altering the gene sequences of the genetic line.

Sometimes there is enough autumn chilling so we get pretty autumn foliage, as we once regularly did. Amazingly, this year, despite the heat and oppressive smoke, we are experiencing an incredibly gorgeous fall display, an event that we have missed for years. This is Acer Palmatum ‘Ornatum’

There are a few flowers remaining on the Zinnia elegans. The rain in October and the foggy weather are quickly bringing an end to the remaining plants. We are enjoying the beauty of the late color turning brown; the shift in colors from bright and exuberant to withering, much as Monet is said to have done with his garden in Giverny.

I allow many plants that might be considered weeds to grow in our garden:

Below center is Potentilla gracilis var. fastigiata. It is a native species that freely seeds around the garden. The species has a good degree of drought tolerance, has attractive foliage and bright yellow flowers. I let them seed around but need to control their numbers and locations.

Above the Potentilla is Verbascum nigrum. I might be getting into trouble with this one! The plant is a seedling volunteer from the Placerville property. I like the dark stems and yellow flowers. I hope I can control them. Various wild passerines enjoy the seeds. It is such a joy to watch the little birds perch and devour the seeds of this Verbascum, Zinnias, Cosmos, Oenothera, Perilla, and others.

Above the Verbascum and slightly to the right is Linaria purpuea. This is the standard purple form. For years only the pink Canon Went seeded around the garden. I am pleased to have the purple form. Linaria purpurea seeds around; however it has never been a problem in our garden.

Also in the photograph are seedlings of Digitalis purpurea. Although I planted these; however, to some extent, the species does seed around in our garden.

Many other species seed around our garden without any help on my part. I really enjoy our California native annual species that seed around in our garden.


The mild and dry weather continues in our portion of Northern California. November temperatures are running ~ 2.5 F (1.39 C) above average in the foothills and Sierra Nevada Mountains. At our Sacramento home temperatures are running ~ 0.5 F (0.28 C) above average.

Precipitation to date in November is 39% of the monthly average. Currently the prospect for more precipitation during the next 10 days appears unlikely. Because of the torrential rainfall in late October, our entire precipitation totals to date are still well above average. Unfortunately, the October storm was very warm and it left very little snow in the Sierra Nevada Mountains. Now--more or less--all this snow has melted leaving us no snow pack in the Sierra Nevada Mountains.

The El Niño – Southern Oscillation teleconnection has a very strong influence on our California weather. The currently intensifying La Niña event is highly conducive to dry and cold weather in our part of California. With climate change, there has been a general trend toward rising geopotential heights in our region: During last winter’s strong La Niña event, the trend toward rising geopotential heights helped influence a shift where much of the cold weather remained north and east of our region; however the typical La Niña dry weather pattern persisted.

With the mild temperatures, common Borage, Borago officinalis, is still blooming in our garden.

Moraea polystachya continues to bloom in the mild weather.

The silvery gray foliage of Arctostaphylos viscida ssp. viscida is appreciated during the late autumn-winter months. The nascent upright inflorescences are very sticky, thus the name viscida. With it so warm, a few inflorescences have already expanded and bloomed with their delightful urns, an important winter nectar source for hummingbirds and butterflies. It is cause for concern, what will these precious creatures have if the weather turns cold? It remains to be seen if indeed it will turn cold, or any significant precipitation will occur. The lack of water is dire; however, that has not halted development and degradation of habitat.

With cool weather and rainfall, the summer dormant plants of Ranunculus occidentalis var. occidentalis quickly emerge from the ground and begin growth. Unlike Ranunculus occidentalis var. ultramontanus, variety occidentalis must be kept completely dry all summer. Hybrids between variety occidentalis and ultrmontanus are showing promise as useful garden plants in our garden, with tolerance to summer moisture and showy flowers.

The seed of Ranunculus occidentalis var. occidentalis germinates quickly after the weather cools in the autumn and the rain begins.


While working in the garden yesterday, I found a plant container full of volunteer seedlings of Echscholzia lobbii and Eucrypta chrysanthemifolia. Generally, fire is necessary to enhance the germination of Eucrypta chrysanthemifolia. I knew there was the possibility to develop a seed line of this species that would germinate abundantly without fire. These seedlings are the results of seed I missed when gathering seed in the late spring of last year. I will sow the seed I gathered soon; hopefully there will be a high rate of germination without fire/smoke treatment.

I have a lot of fun breeding many very common plant species. The two tubs each contain a different seed line of common Sweet Peas. I will cross the two lines with the goal of developing seed lines that germinate well in our relatively warm weather, have a wide flower color range, large flower trusses with many flowers, strong scent, and heat tolerance. Needless to say, all the goals will not be reached with one cross.

I do much breeding work in tubs, especially with small plants. This maximizes use of our small space, pollination and genetic control. Otherwise, containers are a delightful splash of color that can be rotated throughout the garden.

I make my own soil blocks. The first two tubs contain a line of common Viola that I am wishing to improve. Experimenting with common species works very well for me. Techniques I develop with common species frequently can be applied to other less common but desirable species: I like our local California native Viola species, such as Viola purpurea. The new techniques are useful in developing easier-to-cultivate forms of our local native Viola species.

Soil blocks are great for starting seed and transplanting seedlings. Many difficult- to-transplant species, transplant easily when seeded out in soils blocks.

You certainly do an impressive work with plants, Robert! Hope your climate doesn't get too dry for growing plants. Here we had a dry but not too dry summer but the fall (October-November) has been rather wet, well above normal. The temperature has been above average until yesterday when it suddenly dropped (as expected from the forecast) and we got an inch of snow. Cold weather is expected next week also.

Hello Trond,

Our current weather/climatic trends look grim. In the short term, the next 7 to 10 days look dry with above average temperatures. To date, temperatures in November at the Placerville property are running 2.47 F (1.37 C) above average. There is basically no snow in the Sierra Nevada Mountains.

For the winter season the climatic pattern looks equally grim. A La Niña has developed in the equatorial Pacific Ocean. It appears that this will be a fairly strong event and persist through the winter months. This pattern is likely to produce dry winter/spring weather in our region. The current weak and inactive MJO pattern is not conducive to countering this dry trend; however this pattern shows hope of changing in the near future.

As to the future, the paleo-climatic data from our region strongly suggests California may return to a consistently dry climatic pattern where drought is the new normal. I have been experimenting with simple mathematical radiation/energy balance models for our region, comparing our current conditions with how they might have existed during the Medieval Warm Period. The first results suggest California could be rapidly progressing toward a climatic pattern where high temperatures and drought conditions exceed those that were experienced during the Medieval Warm Period. I do not consider my preliminary results conclusive; however they are not encouraging either.

Despite the uncertainties of the future weather I continue to move forward with my gardening projects. In this photograph, the flats are filled with freshly seeded California native annuals and other very common winter/spring annuals (breeding projects). Shortly, I will have all the desired seed lots planted – this is a first in many, many years.

I have a number of seed lots planted of our local California native Viola species. So far, there have been very positive results and incremental progress. This is a nice heat-tolerant form of Viola adunca ssp. adunca that resulted from last year’s sowing of seed gathered from a local low elevation population.

Food security and sustainable farming practices form the core of our current gardening methodology. Here a nice stand of cereal rye, Secale cereal, is coming on nicely.

In another part of the garden is a planting of Ethiopian Two-rowed Barley, Hordeum vulgare. Both cereal crops will likely produce well despite any dry conditions we might encounter this winter/spring. I am very pleased to be growing cereal grains again. Fresh homegrown cereals grains are incredibly delicious!


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