Once Plants Mature, They Become Drought Tolerant

There are certain garden occurrences – you might call them acts of God – that just happen, leaving you suddenly wiser about plants.
Frequently enough, a volunteer seedling emerges and is barely noticed until it is in full flower or turns into a buxom shrub or fruit-bearing tree. On a number of occasions, I have seen this happen with California native coyote brush (Baccharis), fig and loquat seedlings, camphor, ash, elm, oak, and pepper trees, glossy leaf privets and bush lantana and Washingtonia fan palms, which may poke through Los Angeles sidewalk cracks at any time.
So you cannot help but conclude that fig and loquat trees, for example, as well as those palms that pop up all over our city, grow just fine with little water.
Under the influence of benevolent late rains and mild June weather, I have yet to resort to irrigation of two ornamental plants, supposedly thirsty types, that I have been watching without interruption for several years.
Up until this year, I made sure that they were watered once or twice a week but now, having expanded in size to the point where they completely shade their own roots, I did not notice them in need of any water and began to wonder how long they could go without it. Thus, other than rain, they did not receive a drop of water for the first six months of this year.
Yet, lo and behold, they have never flowered as prolifically as they are flowering now, and so I cannot help but conclude that their water requirement is much less than I thought it to be. This may lead to a more general understanding that water, provided excessively, may actually discourage flowering.
The plants in question are chaste tree (Vitex agnus-castus) and evergreen veronica (Hebe). Neither of these beauties ever appears on lists of drought-tolerant plants and yet, once established, they seem to grow fine in barely irrigated earth.
The chaste tree has spicy leaves, large royal blue flower spires, and edible berries that have both anaphrodisiac (testosterone inhibiting) and aphrodisiac (estrogen generating) qualities. During the Middle Ages, monks and priests were known to grow chaste trees in their gardens.
The chaste tree is one of those botanical marvels that, depending on how it is or is not pruned, may be grown as a tree, a shrub or a ground cover. Leave it alone and it will grow into a 20-foot tree, or prune it regularly to maintain a more compact growth habit. It will defoliate during the winter and you will completely forget about it, but this temporary loss of stature is more than compensated for in late spring when it begins to show off its incomparable inflorescences of blinding blue.
More than 10 years ago, I discovered a massive planting of Hebe (HEE-bee) in Woodland Hills from which I took a small clipping. Today, that clipping has grown into a shrub that is four feet tall and wide.
For the last decade, I never saw more than two or three flowers at a time and was lucky if I saw a dozen flowers in the course of an entire year. All that changed this spring when I refrained from giving it any water, seeing how far I could stretch the advantage of late rain and mild weather.
Every year, I had strongly debated whether or not to remove it, asking myself if it made sense to keep something around that took up so much space but barely flowered. I did enjoy its foliage but wondered whether that pleasure was sufficient to justify its garden presence.
All that changed when I suddenly saw my Hebe burst into bloom a few weeks ago.
It should be noted that most Hebes are not this rugged. The types available in nurseries are usually small shrubs with a lifespan of only a few years.
Where these nursery types are concerned, you are wise to take clippings for propagation during the summer. Root the clippings and you will have plants in reserve when the mother plant dies.
It is unfortunate that there is such a small selection of Hebes available in nurseries.
There are dozens of Hebe species and cultivars, mostly native to New Zealand, with delicate, sequined caterpillar blooms in pink, mauve, blue, violet and white. Their shiny foliage varies from simple green to cream and white, to gray, to purple toned. Visit the botanical gardens on the campus of Cal State University, Northridge, to feast your eyes on the Valley’s premier Hebe collection.
TIP OF THE WEEK Joe Varela, of Yosef Amzalag Supply, informs me that the recently introduced Precision Series Spray nozzles, manufactured by Toro, are a major advance in irrigation technology. To the naked eye, water delivery may appear to be the same, whether Precision Series Spray or conventional spray nozzles are in use. In fact, however, Precision nozzles apply water in pulsating jets that, invisible to the eye, replicate the oscillating streams of water delivered by rotary sprinklers, leading to reduced runoff (onto sidewalk and street). In addition, water savings of 10 percent to 15 percent have been confirmed. Filters are pre-attached to Precision nozzles and they are available in both male and female configurations. They operate optimally under water pressure of 20-50 psi. Choose from radii of 5, 8, 10, 12 and 15 feet.

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