The more I learn about primrose jasmine, the more I like it. This time of year, it’s nice to look at, too. Long shoots are bedazzled with butter yellow blooms. Primrose jasmine will cover a pergola, spill over a block wall, serve as a carefree hedge, or do all of the above if you decide to make it a major part of your horticultural experience. And, lest I forget, its water requirement once established is virtually nil and it will survive a freeze down to 20 degrees, in addition to growing in both full sun or light shade. You will still see outcroppings of primrose jasmine along the east shoulder of the San Diego Freeway between Van Nuys and Granada Hills and occasionally notice it brightening up freeway entrance and exit ramps along that route. I am sure these plants never see water except for winter rain and that they are as drought tolerant as oleanders, those other famous freeway plants which, unfortunately, have all but disappeared thanks to a bacterial plague.
The natural growth habit of primrose jasmine (Jasminum mesnyi) is fountainesque, meaning that its shoots, up to 10 feet long, arch up and over like the flight pattern of rockets shot into the sky. This is similar to the growth habit seen on glossy abelia (Abelia grandiflora), another excellent candidate for a whimsical, informal hedge. Maintenance of primrose jasmine involves, primarily, just watching it grow and then, when the time comes, cutting it back as necessary, depending on your purpose in planting it. You can also just let it go. Eventually, its interior turns to thatch as its shade producing exterior growth takes away light from the older wood, which is rendered leafless. At this point, you may want to cut your primrose jasmine back to within one foot of the ground, from where — being an evergreen that grows almost continuously — it will spring back up in no time.
I think people will begin looking more closely at thicket plants like primrose jasmine, Turk’s cap (Malvaviscus drummondii), native tree mallow (Lavatera assurgentiflora), Mexican sage (Salvia leucantha), Salvia microphylla ‘Hot Lips’, Copper Canyon daisy (Tagetes lemmonii) and a large variety of ornamental grasses. You plant these love-to-be-neglected types and just leave them alone until they get out of control or thatchy, at which point you cut them back — late winter is good time to do so — and then wait briefly until they begin to grow again. Just don’t bring them down to ground level, but allow 12-18 inches of the old growth, which generally contains growing points for new growth, to remain.
Although the name jasmine is synonymous with scent, yellow flowers, including those that appear on certain jasmine species, are rather odorless. A plant crafts its flowers to attract insects for pollinating purposes. A plant will invest its energy in producing flowers that are either scented and colorless (white) or colored, but seldom both. It’s an aspect of nature’s economy. The exception here is roses, which makes them so special, since they have both wonderful colors and fragrances too.
Lilac vine (Hardenbergia violacea), also blooming now, has cultural requirements that generally match those of primrose jasmine, except that lilac vine is a bit less cold tolerant. It also may be trained in a variety of ways, whether you want it to just sprawl and cover the ground or climb. When grown as a vine, Hardenbergia does not produce the sort of dense growth you may seek if your objective is to cover an ugly chain link fence or block wall. Hardenbergia serves better as a vining decoration around a light pole, for example.
In its native Australia, aborigines have long used lilac vine roots for making a flavorful drink and thus its appellation of false sarsaparilla (pronounced sasparilla). Typically, sarsaparilla refers to a beverage sweetened by a tropical Smilax plant, whose roots were used not only to flavor drinks but to produce the original root beer foam as well. Botanically, lilac vine is closely related to soybeans and, as a legume, makes its own fertilizer through symbiosis with nitrifying bacteria that inhabit its root nodules.
“I have two cherimoya trees that flower a lot. The problem is: they don’t produce fruit. Is there a way for a chermoya tree to produce fruit by itself without hand pollination and is grafting necessary for the tree to produce fruit by itself?”
Josephine Margi, Covina
Whether you grew your chermioya trees from seeds or planted grafted trees, you will have to hand pollinate in order to get fruit. The reason for this is that in the South American tropical home of cherimoyas, their flowers’ pollinating agents — indigenous insects and breezes that blow at just the right time of day — are uniquely qualified to transfer pollen from male to female flowers. In Southern California, without aforementioned bugs and breeezes, pollination is done with human assistance. Male and female flowers are produced on the same tree and you only need one tree to get fruit. When the tree’s flowers open in the late afternoon, insert a soft paintbrush into a male flower, extract the pollen and then insert it into a female flower.
Incidentally, if you grew your cherimoya trees from seeds, the fruit that comes from them is likely to be inferior to those you find at the market. In order to be assured of quality fruit, you will need to grow grafted trees of named varieties. Whether you pollinate or not, to be under a cherimoya tree when its flowers open is a unique experience. You will imbibe a sweet fragrance that evokes the flavorful essences of the fruit itself.
Tip of the Week: Winter annuals will always exert a special bright and warming magic on account of the contrast they offer to gloomy skies and chilling wind and rain (when we get it). While pansies garner the lion’s share of winter annual glory, violas or johnny jump ups, which are pansies’ smaller cousins, are the most charming of winter annual fare and also self-sow from year to year. Pansy and viola flowers are edible and may serve as a garnish to salads and other dishes. Diascia (pronounced either di-ASH-ia or di-ASS-ia) is a relative of nemesia, only diascia is a larger plant with bigger blooms. It also spills up and over the sides of any flower pot. In most of the country, diascia is strictly a spring and summer annual, but here it starts its distinctive flowery display in winter.