If you want to help increase the monarch butterfly population, plant a milkweed (Asclepias sp.). Milkweeds are the sole food source of monarch butterfly larvae and there is good reason for this. Toxins found in milkweeds are absorbed into the bodies of the developing, leaf-munching larvae, rendering them — as well as the adult butterflies that they become — unpalatable to birds and other animals that would otherwise prey upon them. Yet milkweed species, which number 108, vary in their toxicity, and many species in the young seedling stage, at least, are fit for human consumption.
During the last 20 years, the monarch butterfly population in the United States has declined by 90 percent, which is related to the decline in milkweed stands because of pesticide use, extreme weather of all kinds, recent droughts and loss of winter habitats. Two distinct monarch populations exist, divided by the Rocky Mountains. The population that lives east of the Rockies winters in central Mexico, in fir forests north of Mexico City, while the population west of the Rockies winters in coastal retreats that stretch from Baja California up to Sonoma County, north of San Francisco. Locally you can view hibernating butterflies at Leo Carrillo State Beach in Malibu and at Camino Real Park in Ventura. At both locations, in November and December, you will see flocks of monarchs hanging from eucalyptus trees. Pine, cypress and fir trees are also favorite havens for wintering monarchs.
Growing up in Chicago, I remember netting monarch butterflies and filling large jars with them all summer long. Yet today, in the San Fernando Valley, monarch butterfly sightings have become truly rare events.
There are 15 California native milkweed species, many of them drought-tolerant. If milkweeds were planted in parks, highway median strips, large backyards and other extensive landscapes, the local monarch population could increase.
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Mexican petunia (Ruellia brittoniana) is a highly versatile perennial bloomer for full sun to partial shade exposures. The conventional Mexican petunia grows in a clump and reaches a height of 3 to 4 feet. It is seen with either violet or pink, crepe-textured flowers that bloom as long as the weather is warm. Foliage is an attractive purplish bronze. There is also a dwarf Mexican petunia, spreading far and wide as a ground cover, that is available in violet, pink and white. If grown in lots of sun, you will need to soak your Mexican petunia twice a week, as opposed to shadier locations where once-a-week watering should be sufficient.
If silvery-green to silvery-blue foliage that is deeply serrated appeals to you, consider planting a single honey bush, or three or five of them. One of the principles of garden design is that accent plants such as honey bush, which can rapidly grow to a height of 10 feet, are best and most memorable when planted in odd numbers. In any event, honey bush (Melianthus major) would be a major garden attraction solely on account of its leaves, but it has another attraction, too. Suddenly, without much of a warning, the most unusual wine red, waxy-textured, nodding, unopened flowers appear. These flowers are highly distinctive before they open, but rather nondescript when they finally bloom.
Nick Kurek of Granada Hills sent me a picture of a moraea, African iris, or fortnight lily, describing it as a “very hardy drought-resistant plant.” He grows his “in full sun with little water.” It blooms on and off, although flowers only last “for a day or two and then the pods yield zillions of small black seeds.” If your soil is fast-draining, these seeds may germinate. I have seen it happen often enough. Fortnight lily, while possessing captivating flowers, is rather unsightly when it comes to its foliage, which is a collection of dull green spears that yellow easily and are typically burnt at the tips. Wild yellow iris (Dietes bicolor) is a fortnight lily with pale yellow petals and triangulated maroon markings.
For more information about area plants and gardens, go to Joshua Siskin’s website at www.thesmartergardener.com.. Send questions and photos to [email protected].
