I recently returned from a visit to Jerusalem. While there, I could not help but notice that the most popular April flowering tree in that city is a close relative of western redbud (Cercis occidentalis), a California native tree. In addition to its being a principle street and garden tree, the redbud in Jerusalem (Cercis siliquastrum) flowers more abundantly than in the Valley.
The reason for this is easily explained – Jerusalem’s winter is colder than our own and the redbuds needs a good chill to bloom its best.
In fact, I have noticed that western redbuds in our own area bloom more heavily the farther north you live; they bloom heaviest in the Antelope Valley, still quite well in the Santa Clarita Valley, but somewhat less in the San Fernando Valley. When we have a warm winter, the differences in bloom among our various valleys is especially pronounced.
The western redbud is highly drought-tolerant and only needs a good dose of winter rain to flourish. Summer water will speed its growth but, in nature, it is often found along slope bottoms or winter creeks that quickly dry up with the onset of warm weather. Not only are butterflies attracted to its stunning magenta flowers and birds hungry for its leguminous seed pods; the flowers and young green pods of redbuds may be eaten by human beings as well – in case you are hiking in the chaparral and need a snack.
The western redbud is a full sun tree but its cousin, the eastern redbud (Cercis canadensis), also flowering in magenta, requires some shade. All redbud trees are on the small size, reaching a mature height of 20 to 30 feet and, unless pruned regularly when young, may quickly resemble large shrubs rather than trees.
The eastern redbud also has a white flowering variety (Cercis canadensis alba) and a fascinating purple-leafed variety known as “Forest Pansy.” If you have a partial sun or lightly shaded area that needs an ornamental tree, you just might want to plant a “Forest Pansy.” Its leaves are large, appear from a distance to have a pansy flower’s silky texture, and have a heart shape that also resembles that of a pansy bloom. This tree is susceptible to scale insects so make sure it gets good air circulation and is not planted in a dead-end corner of the yard.
The redbuds belong to a select group of trees that flower before they leaf out in the spring, heightening their spectacular floral display. Certain ornamental plums, peaches and apricots flower before leafing out, as do deciduous magnolias.
Two varieties of the tropical trumpet tree (Tabebuia) have been flowering in the Valley for the past few weeks prior to the emergence of their leaves. Tabebuia chrysotricha is probably the most memorable flowering tree in our midst, its electric yellow flowers invariably making an indelible first impression on novice and veteran tree watchers alike, while Tabebuia heterophylla has pink flowers.
When deprived of winter rain, the Jacaranda tree (a botanical relative of Tabebuia) will flower in a madness of blue-mauve before exhibiting its ferny foliage. Notice also certain of those thorny, muscular coral trees (Erythrina species) will soon be flowering in red or red-orange prior to the appearance of their leaves.
In Jerusalem in April, the most widely seen flowering vine or billowing shrub is primrose jasmine, a plant Valley gardeners may wish to consider for its fragrance and drought tolerance. Primrose jasmine (Jasminum mesneyi) has semi-double yellow flowers that fade to white. The flowers emerge in puffy clusters, so that some gardeners have bestowed the appellation of “popcorn jasmine” upon this plant. One of the best places to view it is when you drive north on the San Diego Freeway near the exit to the Simi Valley Freeway.
Primrose jasmine may be grown as an alternative to bougainvillea. Like bougainvillea, it must be trained to grow as a vine but will admirably grow up a wall, fence, or trellis with the encouragement of plant ties. Left to its own devices, it will spread happily over the ground, whether flat or sloping in terrain.
All plants in Jerusalem gardens are selected for drought tolerance since Israel, like California, is subject to long periods without rain, which may last for several years. All irrigation in Jerusalem is drip irrigation, the scarcity of water prohibiting the use of the kinds of sprinklers we are used to in California.
It is important to remember that whereas our common spray sprinklers deliver water at the rate of one to four gallons per minute, drip emitters and mini-sprinklers deliver water at the rate of one to four gallons per hour. In other words, it takes 60 drip emitters to deliver the same amount of water as a single pop-up sprinkler!
TIP OF THE WEEK: Snails are here with a vengeance. The best way to keep snails out of the garden is to allow fallen leaves to decompose in garden beds. No garden is more attractive to snails than a hygienic garden where rake and/or power blower have removed every shred of botanical debris.
Whether they prefer feeding on fallen leaves to fresh plants or whether they find it more difficult to navigate over rotting leaves or bark than bare soil, it is a fact that snails have little interest in planters where a mulch of leaves or bark is constantly present and where rakes and blowers are not allowed.