I went to Descanso Gardens in La Canada Flintridge to look at the famous rose collection and fall-blooming Sasanqua camellias, but came away with an appreciation for new trends in container planting.
I also marveled at the well-kept displays of water-thrifty ornamental grasses and other drought-tolerant species utilized as companion plants to the roses. There was barely a weed in sight except for that pernicious nut grass (Cyperus esculentus), whose control, if not elimination, is a perennial challenge to us all.
If necessity is the mother of invention, rising water costs and tightening budgets have probably had a role to play in the evolution of container gardens. Annual flowers and fast growers have been replaced with slow-growing, drought-tolerant species. Where color was once achieved with flowers, it is now evident through foliage.
Icee Blue Yellow-Wood is Sensitive to Direct Los Angeles Sun
In Los Angeles, the most distinctive tree for container growing is Icee Blue yellow-wood (Podocarpus elongatus ‘Monmal’). It is shown off to excellent effect at the entrance to Descanso Gardens. The more I see Icee Blue, the more I am convinced that this is a tree that does best when protected from hot sun. While I would not classify it as a shade plant, it definitely performs at full potential only when shielded from anything resembling direct sun.
Icee Blue is a Conifer
Its silvery blue color matches that observed in certain cypresses, spruces and firs. This is not a coincidence since Icee Blue, like these other trees, is classified as a conifer.
Two entrance containers at Descanso utilize silver carpet (Dymondia margaretae) as a ground cover. This remarkable plant grows absolutely flat. Its leaf margins curl upward, its white, hairy undersides exposed, and so it takes on a variegated look, as though its foliage was striped greenish gray and white.
It is a member of the daisy family and it dutifully produces tiny yellow flowers that will remind you of miniature gazanias.
Silver carpet can take light foot traffic when planted in a garden. However, it is slow to establish and unless you plant it so that it completely covers the soil, be prepared to spend a lot of time on your hands and knees pulling weeds until a solid carpet is formed. Once the wall-to-wall carpet has taken hold, however, it becomes quite drought tolerant.
In its Descanso containers, silver carpet is underplanted to green changing to burgundy Japanese maple and yellow bamboo. In both cases, the contrast afforded in color and texture makes for perfect design combinations.
In another entrance container, there is an intriguing triangulation of pink, yellow, cream and green variegated New Zealand flax (Phormium sp.), orange New Zealand sedge (Carex testacea) and Echeveria ‘After Glow,’ the pinkish-purple succulent that grows into giant rosettes. These plants are all water-thrifty species and are therefore highly compatible in the same container.
Australian rosemary (Westringia fruticosa) and a variety of small-leafed pittosporums are also featured prominently in Descanso containers. Australian rosemary is a robust, pale-gray beauty that is seen in both shrub and sub-shrub, compact configurations and it is the latter, growing no more than 3 feet tall and wide, that is in evidence here.
Australian rosemary is slowly gaining the recognition it deserves in the pantheon of drought-tolerant plants. It is one of the few plants that can be reliably planted under pines and eucalyptus. It grows in sun or light shade and, once established, is about as water thrifty as regular rosemary (Rosmarinus officinalis), the type used for cooking.
Australian and culinary rosemary are botanical cousins and neither of them, once established, should require soaking more than once every other week, unless they are planted in containers, where more frequent watering is required. Small-leafed pittosporums, the perfect complement to Australian rosemary, may be variegated, occasionally possess distinctive black stems and always have a freshly polished foliar sheen.
Several succulents, growing comfortably in containers, caught my eye. The most unmistakable was Euphorbia tirucalli ‘Sticks on Fire,’ also known as red pencil plant since it consists of nothing but stems.
‘Sticks on Fire,’ a major horticultural contribution to our part of the world, was made possible by Gary Hammer, the peripatetic nurseryman who recently passed away. Hammer discovered ‘Sticks on Fire,’ in all of its red and gold glory, in the course of his botanical globe-trotting.
Close by you will find a gorgeous chocolate-burgundy succulent that looks like an Echeveria of some sort, with glossy, spatulate foliage.
‘Little Ollie’ (Olea europaea ‘Little Ollie’) is a reliable ball of green that is eminently suited to both garden and container growing. This is actually a semi-dwarf variety of olive that can be kept under 3 feet tall with regular pruning. It also makes a handsome hedge or divider between garden beds.
This is the moment that black-eyed Susans (Rudbeckia spp.) are in their prime, and you can enjoy them lustily at Descanso Gardens. I had always assumed that black-eyed Susans had orange petals and black central cones and was not aware that there are also golden varieties such as Rudbeckia hirta ‘Irish Eyes,’ noted for its brilliant yellow petals that surround green cones.
Descanso has an insectary garden with plants that attract pollinating insects and birds of all kinds. My favorite specimen here was bog sage (Salvia uglinosa), with true blue flowers. It also can handle some shade. Bog sage grows into rhizomatous clumps in either wet or dry conditions. Its erect growth habit and old-fashioned look would make it feel at home in an English garden.
Tip of the week
Zephyr lily (Zephyranthes candida), a ground cover beloved by all, is growing in a corner of one of the Descanso rose beds. This delightful bulbous perennial possesses six-petaled snow-white flowers that peek out from amid deep green, grassy foliage. It blooms on and off throughout the year in partial sun to shady exposures.
To keep it blooming, withhold water after flowering ends. Zephyr lily is a clumping plant and may also be seen in yellow and pink.
Its downfall is excessive watering and/or imperfect soil drainage. Properly cared for, it will last for years and spread vegetatively on account of its bulbs.