A whole lot of hibiscus for your garden consideration
If you lived in ancient Greece and someone told you they were growing a hibiscus plant, you may have then inquired about coming by to roast marshmallows once the plant’s roots were well-established, which would take around two years.
The reason for this is that hibiscus (a Greek word) refers to the plant whose roots contain the fibrous substance — which takes two years to manufacture once the plant begins to grow — from which the marshmallow confection was originally made. The marsh mallow plant (Althaea officinalis) still exists and its small flowers are similar in form to those of the popular Chinese hibiscus (Hibiscus rosa-sinensis) — with which it shares botanical kinship — that we plant in our gardens today.
Should you wish to acquire marsh mallow seeds, you can do so through vendors found on Etsy.com and ebay.com. While marsh mallow needs a moist environment to thrive, such as at the edge of a water pond or anywhere in the garden that stays moist, planting it in a permanently wet bog or swamp is not to its liking. The seeds also need a cold stratification period of two months prior to planting, which can be achieved by placing them in a bag of moist sand in the refrigerator for this period of time. The marshmallows we eat today, as you probably suspect, are made from artificial ingredients.
Ironically, hollyhock (Althaea rosea), a close cousin of marsh mallow, demands polar opposite soil conditions for growth. I have seen hollyhocks growing out of the asphalt of an abandoned gas station and at the base of a stone wall adjacent to a busy street. This is a classic example of the fact that botanical kinship is determined by flower structure alone and has nothing to do with habitat or preferred environmental conditions for growth.
Should you have a water pond and desire a brilliantly flowering plant that can grow there unabashedly, including in the middle of the pond, then you would want to select scarlet hibiscus (Hibiscus coccineus). I first saw this plant growing in a water pond at the Jerusalem Botanical Gardens, but have never seen it in a water pond in the Los Angeles area. I wonder why this is so since the climate in Los Angeles is strikingly similar to that in Jerusalem. The scintillating petals of scarlet hibiscus are not only attractive to our eyes, but their nectaries — located deep within the flowers, at the base of their petals inside the sepals, as in all hibiscus species — are a magnet to hummingbirds too. Another hibiscus species I saw in Jerusalem and am waiting for it to appear in our area is maroon mallow (Hibiscus acetosella). Foliage is shaped like maple leaves that are maroon in color.
The reason I am writing about hibiscus is because, just a few days ago, I noticed my rose of Sharon (Hibiscus syriacus) began to bloom. This hibiscus is not anywhere near as gaudy as the familiar Chinese hibiscus whose flowers appear in brilliant red, pink, orange, or yellow. Still, rose of Sharon has its charms. It is deciduous and so you completely forget about it during its leafless period, only to notice regrowth of its foliage that is eventually followed by summer flowers in mauve, pink, or white that are equally as plentiful as those on the hibiscus we typically see. And rose of Sharon is cold hardy too, withstanding temperatures as low as 10 degrees without complaint. Expect it to grow into a shrubby tree that is 12 feet tall by six feet wide. Finally, an advantage of growing rose of Sharon over the evergreen species is that — probably on account of its deciduous growth habit — it is not visited by whiteflies.
Whiteflies continue to be a major pest on Chinese hibiscus. In seeking a remedy to this problem, I turned to the website of the Southern California Hibiscus Society (socalhibiscussociety.org). The most benign solution is application of worm castings around the base of the plant. The reason behind this practice is that worm castings contain an enzyme known as chitinase that breaks down chitin, the major constituent in the exoskeleton of many insects, including whiteflies, aphids, and leaf miners, as well as spider mites. You can purchase worm castings (a euphemism for worm poop) by the bag or bring red wigglers into your life for a constant supply of their excretions. You can find bins and trays for growing red wigglers through a multitude of Internet vendors by searching “make your own worm castings.” The problem with worm castings is that they are often applied in a thick layer that stays wet and creates anaerobic conditions in the soil or around the crown (where trunk meets roots), causing a bacterial infection that impedes plant growth or worse. If you do use worm castings, it is sufficient to dust them around the drip line of your plant every other week.
A more reliable whitefly abatement program starts with spraying fine horticultural oil on the whiteflies resting on your hibiscus leaves. Make sure this is done just before or after the sun is out since spraying during the day can burn the leaves. You will want to continue to spray as long as you see whiteflies since they will continue to hatch from unseen eggs. In addition to contact control by means of spraying, Safari is a recommended systemic product you can apply; its granules come in shredded form so they easily dissolve in water and, in solution, can be watered into the soil at the plant’s drip line. Bayer Advanced Tree and Shrub is also effective but it takes longer to act since its granules are applied dry and take time before they break down and their active ingredients can be absorbed by roots.
Before leaving hibiscus, I must direct your attention to Annie’s Annuals and Perennials (anniesannuals.com). There you will find a few hibiscus species that you won’t see anywhere else and you may want to consider for planting in your garden. One of these is pink hollyhock tree (Hibiscus splendens). The plant can put on eight feet of growth in one year and produces a plethora of six-inch diameter blooms. Cotton rose mallow (Hibiscus mutabilis) also displays six-inch flowers, only these are darker pink in color, on a plant that reaches a more manageable height of six feet. Finally, although not available at the moment, you will find Florida cranberry (Hibiscus sabdariffa) with stunning, edible red calyces that remain once flowers have fallen and can be used in a variety of recipes for baked goods, stews, chutneys, or simply for making tea.
California native of the week: Sonoran false prairie clover or California Marina (Marina/Dalea orcuttii) is a rare native species. Its false clover appellation comes from the fact that, although it is like clover in being a legume, with some similarity in leaf and flower, it is not a true clover. This plant is a perennial that grows in rocky terrain. It is a delicate little thing that reaches 4-8 inches tall and bears no more than 15 leaves at a time. Foliage is soft and gray with pinnate leaflets upon which tiny hairs, providing insulation from the heat, are pressed. Flowers are violet in color. If anyone knows a source for this plant or its seeds, please advise.
If you have a hibiscus tale to tell, please send it along to joshua@perfectplants.com. Your questions, comments, gardening predicaments and successes are always welcome here.