Walking in my neighborhood the other day, I saw two sights worthy of mention here. One carries with it a cautionary note and the other an opportunity for adding a distinctive ornamental touch to your garden.
On the trunk of a eucalyptus tree, mushroom conks were growing. A conk is the fruiting body of a bracket or shelf fungus. Many years ago, a large branch broke off near the base of this tree and the conks had developed in a trunk depression created at that time. A properly healed tree wound closes over completely by growth of surrounding cambium tissue but here a gaping wound had remained.
Microscopic fungal spores are everywhere and it took many years but one finally gained entry into the tree, a sign that the interior wood is beginning to rot. The vast majority of fungi or mushrooms (the fruiting bodies of certain fungi) are known as saprophytes (sapro = decay [nourished], phyte = plant), as if to say fungi are plants that feed off decaying organisms, even though fungi are not actually plants since they do not make their own food through photosynthesis but derive it from decomposing organic material.
The lesson here is to make sure trees are annually checked for large, lopsided branches that could break off; they should be removed prior to winter storms. I have seen immense eucalyptus trees – sometimes leaning, sometimes straight – topple over in heavy rain since their roots are shallow; if you have a large eucalyptus growing in sandy soil, you will need to keep it continually thinned out to ensure it does not fall during a storm. On several occasions, I have seen Italian stone pines (Pinus pinea), those with flat canopy domes, topple over as well when their canopy growth was significantly asymmetrical.
There are 40,000 species of fungi in North America; 250 are poisonous. Bracket conks, for example, are nontoxic. Nevertheless, extreme care should be exercised before taking a bite from any mushroom. Toadstools and other lawn mushrooms are generally nontoxic but, as a rule, it is not a good idea to let puppies or small children outside before removing mushrooms from the lawn or garden. Mushrooms sprout where compost was applied, where an old piece of wood is decomposing, or where a tree stump or its roots have rotted. Thus, mushrooms can be a positive sign, indicating a high level of soil fertility. Digging out mushrooms does not cause them to spread, and they should disappear without special treatment. You can identify mushrooms you find in your garden or elsewhere at mushroomobserver.org. Following free registration, you enter the geographical location of your mushroom, upload its photo and, shortly thereafter, one of the mushroom mavens who visits the site will reveal its identity.
Besides the conks, a China doll (Radermachera sinica) tree was the other noteworthy encounter made on my recent walk around the block. Regaled as a sturdy houseplant, China doll needs a good dose of bright light indoors, but outdoors it does best grown in half-day sun or shade. Years ago, I saw a mature China doll at the Los Angeles County Arboretum in Arcadia that was thriving in partial sun. China doll is one of the most elegant plants in the world. It has delicate bipinnate leaves that are a deep shiny deep green in color. It is also known as the emerald tree, perhaps on account of its opulent, sparkling, gem-like mien. This is not a shade tree, but has highly ornamental foliage and a radiant look that are second to none. China doll is surprisingly hardy. Although it is native to the Philippines and is sold everywhere as an indoor plant, it has thrived in outdoor gardens in California as far north as San Jose.
In tropical settings, China doll puts on explosive growth, reaching its mature height of 30-plus feet in just a few years. In our drier climate, however, it may never reach that height. Tropical plants growing in subtropical, temperate, or Mediterranean climate zones such as our own often do not reach their full genetic potential. Still, tropical plants that can grow outdoors in our area develop a tolerance for dryness, but only as they mature. The Hawaiian elf (Schefflera arboricola) is the best example of this. This common indoor plant will grow into an outdoor garden lover’s 6-foot-tall by 6-foot-wide shrub with umbrella-shaped leaves and orange berries in shade or partial sun. It will require regular water until firmly established, but upon reaching maturity will need only as much water as most other woody shrubs, including natives. If you have a story about a plant generally grown indoors that has succeeded in an outdoor environment, please send it to me so I can share it with readers of this column.
California native of the week: Incienso or brittlebush (Encelia farinosa) is a mounding plant with silver foliage and yellow daisy flowers. Incienso means incense in Spanish and refers to its resinous sap that was used for this purpose in the early Spanish missions of the Southwest. Its foliage is also potently fragrant. The brittlebush epithet refers to its stems that are easily broken. Its species name of farinosa is attributable to the mealy (farina = meal or flour) texture of its foliage due to the presence of matted hairs. Sun-reflecting silver foliage and hirsute foliage are both characteristics of drought-tolerant plants and this one is at the top of that list. It may be short-lived but as long as soil drains well, seeds should easily self-sow and new plants should always be coming along. As you go north on the 405 Freeway where it leaves the San Fernando Valley, look to your right and you will see a mounding silver leaved shrub that has completely covered a slope. Caltrans has been hydroseeding brittlebush throughout Southern California and this accounts for its spread into areas beyond its habitat.
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