Now that unseasonably high temperatures have become the norm, the idea of planting tropical fruit trees would seem to make more sense than ever.
Perhaps the key to successful growing of tropicals is to remember they are evergreen and require constant fertilization throughout the year. Where mature trees are concerned, it may be enough to cover the soil with mulch.
At the Papaya Tree Nursery in Granada Hills, proprietor David Silber is an advocate of sheet composting, which is a fancy term for disposal of fruit and vegetable peels and other organic matter directly under a tree. That is the extent of the fertilization program administered to his mature white sapote, Oro Blanco grapefruit and seedless Valencia orange trees.
As the discarded fruit peels decompose under the trees, their constituent minerals are released into the soil. The feeder roots of tropical trees, quite shallow as an adaptation to the high rainfall and humidity of the tropics, then absorb the newly available minerals provided by the mulch.
These feeder roots will also be kept cool when covered with the nurturing mulch, resulting in a tree that is much less stressed, overall, than it would otherwise be when summer’s heat is at its most intense.
When grown in containers, tropical trees will need to be kept on a steady diet of fertilizer. Special fertilizers custom-blended for citrus and avocado trees are available in most nurseries, and these products should be effective with most other tropicals as well.
–When a plant has leaves with green veins and yellow spaces between the veins, it is a sign the plant lacks iron. This condition, sometimes called interveinal chlorosis, is often observed on tropical trees. To prevent the development of chlorosis, make sure your fertilizer includes a full complement of micronutrients, including iron, zinc and manganese.
One tropical plant particularly prone to chlorosis, but one that can be grown in protected Valley locations, is coffee (Coffee arabica). Coffee is a relative of the gardenia, a plant that probably shows chlorosis as much as any other. The gardenia is native to the acidic soil of subtropical China, not unlike the acidic soil in the Southeastern United States, where gardenias are most easily cultivated in this country. Where you have heavy rainfall, the soil is acidic; in dry climate areas like our own, the soil is typically alkaline. Thus, it is often a struggle to grow gardenias here but they, like the coffee tree, can be grown with a constant feed of acidic fertilizer. At Papaya Tree Nursery, I was informed by Alex Silber, the owner’s son, that the red fruit pulp that covers the coffee seed or “bean” is sweetly edible. The nursery, open by appointment, can be reached at (818) 363-3680.
Tanya, who lives in the San Fernando Valley, sent the following e-mail: “I want a tree for my front yard that is lacy, easy to grow and drought tolerant. In my back yard, I would also love a tree in the corner of my block wall.”
For your front yard, I would recommend the silk tree (Albizia Julibrissin) for shade and the California native palo verde (Cercidium floridum) for attracting birds and other wildlife. Both have the tiny pinnate leaflets and are drought tolerant. For your block wall, I would recommend a jujube tree (Zizyphus jujube). It has a columnar growth habit, shiny green foliage, and requires little water. In addition, it produces a delicious fruit known as a Chinese date.
GARDEN WONDERS
Gardener: Ellen Sarture
Residence: Sherman Oaks
Plant of interest: Schefflera
What makes this plant amazing: Sarture’s schefflera was barely 3 inches tall and close to dying when it was kept in a pot indoors. Not putting too much hope in its survival, Sarture took it outside, where she planted it in the shade beside her house. There, she said, the plant put on so much growth in a few short days, it reminded her of something out of “Jack and the Beanstalk.”
“We tried slowing it down once by topping it at its roof. It just shot back up, sending out two shoots, which reach around 45 feet tall in one area. It’s twice as tall as our house, which is one story. It finally slowed down, but it’s not stopped – we can’t possibly reach the top of it now.”
Maintenance: “I didn’t really do anything; did nothing to the soil. It’s just in an area besides the house where some ferns and some camellia are. It’s in a shady area.”
What Joshua Siskin says: “Schefflera can grow phenomenally fast. It’s a semi-tropical to tropical plant from Australia, related to ivy. Some people call it an umbrella tree. You can grow this plant outdoors, as long as you grow it in shade. It grows fast to 20 feet or more; anything above that is out of the ordinary.
“You can keep any large plant small if you prune its roots and keep the top of the plant pruned back. But a lot of tropical plants have the genetic predisposition to put on a phenomenal amount of growth. Take any plant, and if the conditions are very hospitable, it’ll grow like there’s no tomorrow. That’s certainly the case here.”
– Mike Chmielecki