Sword rosefill (Volvopluteus gloiocephalus) (Photo by Joshua Siskin)
I have never seen as many mushrooms in my garden as I have this spring.
Mushrooms are indicators of organic matter in the soil since most of the mushrooms we see are nurtured by it. I never cease to marvel at how mushrooms grow up overnight. In a garden spot where nothing was to be seen the previous day, there will be a large single specimen or a significant clump of mushrooms, which you approach in awe as you contemplate the rapidity of their development.
In the nick of time, the Audubon Society’s “Mushrooms of North America” (Knopf, 2023) has just been published with lavish photos of 668 mushroom species. Seeing a cluster of white mushrooms emerge overnight from wood chips that I employ as mulch, I took a photo, including both the cap from above and the gills from below, and sent it to mushroomobserver.org.
This is the website you go to for mushroom identification. Registration is free, giving you immediate access to a large community of mushroom mavens; typically, someone will have identified the species you uploaded within a few hours. Sure enough, in a little more than one hour, my mushroom was identified as sword rosefill (Volvopluteus gloiocephalus). Checking with my new mushroom guide, I learned that the habitat of this species is “grass, gardens, wood chips, and similar disturbed and open areas” and that it is “ubiquitous in California.”
Shiitake mushrooms, by the way, like those found growing in my wood chips, are saprophytic. This means that, in the manner of most mushroom-forming fungi, they receive sustenance from dead or decaying organic matter.
I also saw a strange-looking growth on my wood chips which I uploaded to the site. I soon learned that it is a slime mold that may appear white, yellow, or orange with the unfortunate names scrambled egg slime and dog vomit slime mold (Fuligo septica). Formerly classified as fungi, slime molds have the capacity to actually ambulate like slow-moving snails in their plasmodium stage of development. Slime molds are now classified as protists, placing them in the same category as most algae. While they are decomposers like bacteria and fungi, slime molds may also feed on these organisms.
The Audubon guide does not indicate whether any of the mushrooms pictured are edible. This is a sensible policy since certain poisonous mushrooms closely resemble edible ones. About 2-3% of mushrooms are highly poisonous; 3-4% are edible and flavorful. Fifty percent are considered “edible but not incredible” while 25% are too tough to chew and another 20% make you ill but not fatally so. As to the sword rosefill in my own garden, it is in the “edible but not incredible” category so I am not about to taste it.
It is to be noted that while all mushrooms grow from fungi, only 1% of fungi produce mushrooms or fruiting structures and nearly all pathogenic fungi – such as powdery mildew and the orange rust you see on rose foliage – are not mushroom producers. The notable exception here is the honey mushroom (Armillaria mellea). It is also known as oak root fungus, a parasite that grows into the roots of oaks, but is also lethal to most trees – except for the ginkgo (Ginkgo biloba), which has shown resistance to it.
In fact, a long list of our common garden plants are susceptible to oak root fungus, although many California natives are not. In the manner of many soil-dwelling fungi, Armillaria spores (fungus “seeds”) are ever present in our soil and are just waiting for the right circumstances – inadequate drainage or standing water – to germinate.
Since many California natives do not need to be watered once established, the drier and generally well-drained soil in which they grow does not allow for Armillaria proliferation. Among natives resistant to oak root fungus, Yerba Buena Nursery in Half Moon Bay lists the following: coast redwood (Sequoia sempervirens), bay laurel (Umbellularia californica), California lilac (Ceanothus spp.), Oregon grape (Mahonia spp.), spice bush (Calycanthus occidentalis), and western redbud (Cercis occidentalis).
The mushrooms you see at the base of an Armillaria-affected tree are poisonous when raw – and even after being cooked some people become ill following their consumption, although they’re said to be a delicacy in certain parts of the world. (Ed. note: As always, we don’t recommend you eat anything without being absolutely sure of its safety.)
Some of the most highly valued edible mushrooms – truffles, chanterelles, and morels – grow from mycorrhizae, a class of fungi that live in symbiosis with tree roots (myco = fungus, rhizae = roots). Underground mycorrhizae filaments absorb nitrogen, phosphorus, sulfur, and zinc from the soil; these elements are then supplied to trees through their roots. In return, mycorrhizae receive carbohydrate essential for their growth via the tree roots to which they are attached.
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“The Color of Roses” (Ten Speed Press, 2023) is an ode to the 300 favorite roses of the author, Danielle Dall’Armi Hahn. She is the owner of Rose Story Farm in Carpinteria. The farm is spread over 15 acres and consists of 40,000 rose plants, from which cut flowers are sold to the trade. Among the 300 varieties pictured in the book, there are two whose roses are green and two – the deep apricot Brandy and the lavender to purple Fragrant Plum – whose hybridization is owed to the efforts of the late Jack Christensen, longtime garden columnist and contributor for this newspaper company.
As far as integrating roses into our gardens, Dall’Armi Hahn suggests matching the color of roses to the color of the house, as long as the rose color is of a shade more dominant than that of the house. The author recommends the sunset colors of pink, coral, apricot, and yellow for a stimulating effect.
On the other hand, “cool colors create depth and can make a garden appear larger” while “pastel colors soothe the eye.” As for flower arrangements, single colors of deeper shades provide a formal look, while mixed colors “create a more friendly feel.”
Although the main business of the Rose Story Farm is in cut flowers, rose bushes for garden planting are also available. Visits to Rose Story Farm must be arranged in advance and you can sign up for a tour at rosestoryfarm.com.
Native plant of the week: California bay (Ubellularia californica) grows into a tall, stately hedge and is generally immune to disease and serious insect infestations – unlike the popular eugenia that is frequently used as a hedge but whose leaves are often puckered by aphid-like psyllids. California bay can grow in sun or shade but will do best in soil that stays slightly moist. Related to the bay laurel (Laurus nobilis), whose leaves are commonly used in cooking, California bay leaves are more pungent and their fragrance is wafted a considerable distance on warm days. Although also appropriate as a seasoning, a report from ediblemontereybay.com states that “a single leaf has enough potency to overpower a five-gallon batch of soup and render a small pot completely useless.” Clearly, a little bit of California bay goes a long way. In its habitat, California bay can grow up to 100 feet tall; trained into a tree with multiple limbs rising from the base of its trunk, it will reach around half that size under ordinary garden conditions.
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