Category Archives: Plants

Mediterranean Climates- Chile

Part 4 of our series on mediterranean climate regions-

The mediterranean region of Chile is a small narrow strip of the central section of the country. It is very similar to California in character but with a few key differences. Although possessing a similar layout of coastal range central valley and bounding mountains, Chile is a good deal narrower than California. The result is a smaller growing area. In addition the Andes mountains to the east are 50 percent higher than those of California. The surrounding topography and geography of Chile make it somewhat of an island in character, isolated from outside influences. As a result, many of the plants found in this portion of Chile are native.

Native Genera Examples:

Puya– Native to south America this genus consists of 170 species. These plants are bromeliads and require little to no water. They have course textured leaves and are used commonly in gardens as shrubs. They possess a well developed root system. Many varieties may grow as a large evergreen clump up to 10 feet across with narrow leaves up to 2 feet long. They may reach as tall as 6 feet in the spring blooming season. Flowers are wide with bell shaped blossoms in metallic blue, green, and turquoise. Commonly these are used in large rock gardens, on banks, are good with cacti, and can tolerate poor soil conditions.

Maytenus– This species includes 225 trees and shrubs native to South America and the Caribbean. They have variable shaped leaves, and small star shaped flowers. Some species have red or yellow decorative seed pods in fall. They grow best in locations with long hot summers, and are very sensitive to frost. They do best in fertile well drained soil and can be grown best in full sun or slight shade

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Ugni– This is a small genus of evergreen shrubs closely related to Myrtus. It is indigenous to areas of South and Central America and parts of Mexico. It has glossy attractive foliage and fruits, which is a main reason why it is grown. They do best in well drained moist soils. They prefer partial shade to full sun. They are best pruned back in winter months and propagated in summer.


Mediterranean Climates- Australia

Part 3 of our series on mediterranean climate regions-

The mediterranean section of Australia consists of two bands on the southern portion of the continent. Specifically these are the southwestern part of the state of Western Australia and the southernmost part of the state of Southern Australia. Of these two areas the western section of mediterranean climate has more diversity. The influence of mountains in these areas is minimal, making Australia unique in this regard among mediterranean climates.

Native Genera of Note:

Grevillea– This genus consists of over 250 species of evergreen shrubs and trees, as part of the protea family. They are as a group variable in habit of growth, with all species being native to Australia, or the south pacific area. They usually have small flowers grouped into larger flower heads, with distinctive long styles, that give the flowers an interesting look to them. They are as a group adaptable and easy to grow, characteristic of their mediterranean origins. Leaves may be divided or ornamental as well, with some types being used for cut foliage. There are several hybrids available, which have been bred to be more floriferous.

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Hardenbergia– This small genus consists of 4 species of legume climbers. They typically have leaves divided into three leaflets, that are densely veined. They have clusters of small purple or pink flowers and do best in similar climatic areas with mild winters. They prefer rich well drained soil, and grow in full sun or partial shade.

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Acacia
– This is a huge genus of over 1,200 species of which 700 are native to Australia. They range from low growing shrubs to trees in character, and have generally bipinnate leaves, or flatten stalks that have replaced the leaf’s role and undergo photosynthesis. They have small flowers appearing in either groups or spikes and are often fragrant. Some species need fire to germinate. In horticultural cultivation many species maybe short lived, living only 10-15 years.


Mediterranean Climates- California

In our continuing series about plants and the mediterranean climate we profile our local California climate.

California:

As a state California has an extremely diverse natural landscape. Its mediterranean climate extends inland from the Pacific Ocean to the foothills of the Sierra Nevada. It is these two influences that have the largest effect on California’s climate as whole. It should be noted that some people classify the extent of the mediterranean region of the west coast to extend through Oregon and Western Washington. These areas while receiving differing rainfall patterns also have predominantly dry summers, and it is feasible to group them into this mediterranean region.

Native Plant Genera of Note:

Quercus– This species of over 600 plants is native not only to the mediterranean regions of California, but also to a variety of other climates, including the Mediterranean itself. Plants consist of evergreen, semi-evergreen or deciduous trees and shrubs. They can range in height anywhere from 3 feet to 120 feet depending on species and conditions. Leaves tend to be well adapted to mediterranean climates and are often tough and leathery. In California many species are intolerant of summer watering, and make up a considerable portion of woodland habitats. They have deep spreading roots and generally have large spreading canopies. Flowers are insignificant, although acorns provide food for wildlife and were traditionally used in California as a source of food.

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Arctostaphylos: this genus consists of over 50 species, of evergreen shrubs including two rather rare small trees. These are tough plants with adaptive woody stems, leathery leaves and small clusters of white or pink, bell shaped flowers. The round leaves are oriented vertically to avoid sun drying and sunlight. Small reddish fruits appear in summer. They do best in full or partial shade and are fairly drought tolerant. Manzanita attributes for a considerable portion of California chaparral communities and is not exclusively native to mediterranean climates.

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Eschscholzia– A relative of the poppy, the most commonly found California poppy is the state flower of California. It has large petaled flowers and intense orange or yellow blooms. A variety of other colors are available as a result of hybridization. Foliage tends to be fine and carrot like. Generally plants are small and grow up to a foot high and slightly narrower in spread. They are highly drought tolerant and adaptive to California’s mediterranean climate. They also naturalize readily under proper conditions, and have a somewhat wild, rustic character to their habit of growth.

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Introduction to the Mediterranean Climate

In a series of posts this week we will highlight the mediterranean climate that characterizes California and 4 other regions of the world.

Mediterranean climates are unique from any other throughout the world. They are loved by gardeners for their relatively moderate temperate temperatures with more or less mild extremes in the winter or summer. As a growing environment for plants they provide a good place to grow many differing types of plants from a variety of different climates and locations throughout the world. The mediterranean climate is characterized mainly by its unique rainfall patterns, receiving little or no rain in the summer, abruptly contrasted by wet winters.

Specifically these climates occur exclusively between 30 and 45 degrees in latitude throughout the globe, and tend to predominate on the western edges of these areas. The mediterranean climate plays host to some of the most interesting and uniquely adapted plants in the world. The five areas considered mediterranean climates are southwest and southern Australia, coastal and central California, central Chile, the majority of the Mediterranean basin bordering the Mediterranean itself, and the southwestern tip of South Africa. A diverse and interesting host of plants grow in these climates, even though the total area of the mediterranean climates throughout the world is only approximately two percent.

The mediterranean climate results from a number of unique, important and complex factors. Almost all the areas of the climate occur sandwiched in between a strong maritime influence and a defining band of mountains (except Australia). Almost all these areas also have predominately western orientation, the result of which is often a high pressure accumulation that is a major contributing factor to the climate’s dry summers. In addition, this western orientation ensures exposure to the prevailing western winds of the world, which extends the effects of sea, moderating temperatures, and making temperature extremes characteristic of interior continental areas rare.

The areas also are subject to cold-water currents that help to moderate temperatures during both the warm and cool seasons. Specifically, these currents are the California current in eastern pacific, the Humboldt current in the south eastern part of the pacific, west of Chile, the Bengueh current in the Atlantic ocean off the western part of South Africa, the Canaries current in the Atlantic off of Morocco and Portugal, and the warm Leewin current in the southern Pacific ocean off the western coast of Southern Australia. It is these currents that also help moderate temperatures, and ultimately play a role in precipitation patterns.

Precipitation patterns for the various regions vary, however for the majority of locations the average rainfall is between 30 and 45 inches. Areas receiving more or less rainfall usually lie on the edge of a mediterranean region or are influenced by increased or decreased precipitation due to elevation differences. Characteristically, these areas rarely receive summer moisture. This trait is exaggerated in the interior portions of the climate. As one travels toward the ocean, the greater influence often provides moisture in the form of frequent summer fog. Plants adapted to coastal mediterranean conditions may have completely different characteristics and tolerances from those found further inland.

Mediterranean plants as a group have developed several unique adaptations that help them do well in a climate characterized by a long dry season. Plants may develop a shrubby habit of growth, with tough adaptive leaves. This helps to conserve water during the summer months. Other leaf adaptations include specialized stomata that prevent excessive transpiration, and extensive hairs or toment that help the plant deal with arid conditions. Often plants will not go deciduous because of the energy, nutrients and water needed to put on new growth every year. Plants may also develop a period of inactivity or dormancy, or may even go deciduous in the summer as a response to drought or extensively dry conditions. In addition, plants may develop deep spreading roots to help gather as much moisture as possible.

Still other plants develop an annual habit of growth that helps them to deal with changing climatic conditions. Some plants are even more highly specialized. In chaparral and other similar plant communities plants may develop specialized seeds that open only under intense heat as a response to frequent fires in these areas. Although as a group the mediterranean plants are highly adaptive this does not mean that all plants possess these traits, or even require them. Again, it is important to remember that there are fairly distinct differences between the immediate coastal areas and the inland mediterranean areas. Just because a plant is mediterranean in origin does not necessarily mean that it will survive or thrive if taken out of its particular niche.

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Image from Wikipedia

Resources

1. Brenzel, Kathleen Norris, ed. Sunset Western Garden Book. Menlo Park, CA:Sunset. 2001.

2. Dallman, Peter R. Plant Life in the Worlds Mediterranean Climates, Berkeley: University of California press. 1997.

3. Hawkins, Lester. “Gardener’s Guide to Mediterranean Climates.” Pacific Horticulture. Winter 1980-81: 21+.

4. Turner Jr., R.G. Ed. Botanica. Barnes & Noble. 3rd ed. 1999.
For more visit:
Wikipedia’s article on mediterranean climate
Mediterranean Garden Society

Many Choices in New Zealand Flaxes

I was at one of our main wholesale nursery suppliers last week leading clients on a tour for a planting design. One of the things that struck me while I was there was the amazing number of flaxes available.

For those not familiar with New Zealand Flax (Phormium sp.), they are a New Zealand native that are part of the Agave family. They grow best in the US along the coasts- throughout the Pacific Coast, Gulf Coast and Atlantic Coast up to Virginia.

New Zealand Flax is a versatile plant for California gardens. It’s grassy strap like leaves help it fit well with a number of styles, especially Mediterranean compositions, and those using ornamental grasses.

Colors range from reds, purples, yellows, oranges and multicolors in sizes 18″ and below to 10′ and larger. Among those we use most are cultivars ‘Dusky Chief,’ ‘Yellow Wave,’ ‘Tom Thumb’ (Dwarf), ‘Jack Spratt’ (Dwarf) and a host of others. Cultivars are from two species Phormium cookianum and Phormium tenax.

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Dwarf Tom Thumb Flax mixed with Ornamental Blue Oat Grass

Find good links to images and more information at:
Monterey Bay Nursery Site
San Marcos Growers
Monrovia