– Irwin Goldring, Sherman Oaks
Answer: For the uninitiated, Roger’s Gardens is a retail nursery in the Corona del Mar neighborhood of Newport Beach that has a reputation as the premier destination nursery in Southern California. A destination nursery is a place you visit because of the experience of going there, much the way you visit an arboretum or a botanical garden.
Roger’s Gardens is famous for showing off its plant selections in original and vivid display gardens.
There are several dwarf avocado varieties, including ‘Don Gillogly,’ ‘Holiday,’ ‘Little Cado,’ named for its small fruit, ‘Gwen’ and ‘Whitsell,’ whose mature heights range from 10 to 15 feet, while conventional trees grow to around 50 feet. If your variety is a ‘Don Gillogly,’ I would not be surprised at your lack of success since nearly all reports on the performance of this tree are negative.
The dwarf ‘Holiday,’ on the other hand, is a more reliable performer. In general, dwarf avocado trees are less vigorous than normal sized trees. Where soil drainage is less than perfect, all avocado trees are susceptible to a debilitating root fungus.
Yet, since they require a steady moisture supply, watering can be tricky, especially when trees are young. The fact that the top of your tree is stressed could be a sign of root rot since wilted shoot terminals are the first sign of root problems. Despite evidence of dwarf trees bearing fruit in containers, it is wisest to plant them in the ground. The best mulch for avocado trees is their leaves which, after they fall and are spread under the canopy, may inhibit root fungus development. Avocado trees are heavy feeders and it is advisable to apply a fertilizer especially formulated for them. You can find such a product, usually labeled “for citrus and avocado trees” at most nurseries. Burnt tips of leaves are not unusual and are not necessarily a cause for alarm since fertilizer salts, as they move up through the tree, are sequestered in leaf tips and margins. Bud drop may be attributed to inadequate water supply, brought on by stressed or diseased roots, or to lack of mineral nutrient availability.
Q: I am a member of the San Fernando Valley Historical Society, and we have received a palm tree growing in a wooden box. Our tree is from the Lankershim Collection, and was donated to us with other items for protection and display at The Andres Pico Adobe in Mission Hills.
This tree is quite distressed and has not been receiving any proper care. The tree (about six feet tall) is about the right size for the box that it is in, but the soil has washed away and exposed some of the roots.
Before it was moved to a new location two weeks ago, it had also rooted itself through the bottom of the wooden planter to the ground. I would like to add some soil and TLC for this poor thing. I am not new to gardening, but I have never even thought about palm trees. What type of soil is best to add: potting mix, soil amendments? What about light: full sun or partial shade?
– Roy Bossier, Winnetka
A. While your tree may be somewhat distressed, most of its fronds appear healthy. Wooden containers are plant friendly because their porosity makes it easier for roots to breathe and waterlogging in the pot is rarely an issue. Also, tropical plants, including palms, have shallow root systems so that they can grow quite large in small containers.
It appears that you have a Kentia palm (Howea forsteriana), named for British botanist William Kent, a classic indoor plant which may be grown outdoors in the Valley if you can protect it from hot sun and freezing cold. It probably can handle more shade than any other palm. Use any all-purpose soil mix, mixed 50/50 with perlite, sand, or fast-draining top soil if you transplant it into a larger container. Apply a fertilizer specially formulated for palm trees, such as Whitney Farms Palm and Hibiscus Food or Woodace Palm Special.
If you see an opulent palm tree in a hotel lobby, it is most likely a Kentia. The fronds (leaves) of this palm can extend to nine feet in length. The Kentia is most beautiful when young. As it grows older, its spindly trunk becomes the focus of attention rather than its voluptuous leaves.
Many front yards in Hancock Park are homes to mature Kentias. It must have been stylish two or three decades ago to plant these palms in that part of the city. But you can grow Kentias in the hottest parts of the Valley, too, as long as you give them shade and regular water.
The Kentia palm’s habitat is found exclusively on Lord Howe Island, an extinct volcano remnant that is only seven miles long and one mile wide, located in the Pacific Ocean 400 miles east of Australia. The inhabitants of this island derive their income primarily from export of Kentia palm seeds to tropical plant nurseries throughout the world.
Michael Kappel, a master gardener in Westwood, makes a point of growing plants that you do not often see. He is particularly fond of a perennial geranium called ‘Jolly Bee,’ which he first saw at the Getty Museum garden in Brentwood. ‘Jolly Bee’ flowers in lavender blue nearly non-stop throughout the year. Poppy mallow or wine cups (Callirhoe involucrata) is another stunning selection from Kappel’s garden, its privileged status earned by silky red flowers, snowflake shaped leaves and a modest water requirement.