cherimoya tree, Granada Hills, CA

Q: I want an evergreen tree without a wandering root system that produces shade but is clean since there is a pool to consider. I have been considering an Exoniensis magnolia (Magnolia grandiflora variety). Would this be a good choice?
P.M. Fagan, Granada Hills
A: Every tree produces litter of some sort. Magnolias drop most of their leaves during a five-month period, from May to September, when you’ll probably use the pool most. They also have “wandering roots,” which have been known to push up sidewalks and pool decks.
Accept the litter as a given, but control root growth, if you desire, with a root-control barrier. This barrier may be one large plastic ring sunk a foot deep into the ground or a series of modular plastic pieces that can be snapped together to the desired dimensions. The city of Los Angeles uses such
barriers for new street tree plantings.
The evergreen magnolia you wish to plant is a tree of distinction. It is a primitive plant, perhaps the oldest flowering tree on earth. A magnolia grown from seed may take 15 years to produce a flower, but the fragrant 10- inch-diameter blooms are worth waiting for. If you get a named cultivar such as Exoniensis – which has a symmetrical, conical canopy – it will be a grafted plant, and will begin to flower within a year or two after planting.
The root of a magnolia is succulent and delicate. Take care to dig the planting hole three times the diameter, and the same depth as the root ball. Fill the hole with water and let it drain all the way through. Then fill the hole with water a second time and let it drain again. Waiting for the water to drain may take the better part of a day, but extra time when planting is insurance against desiccation of roots and leaves before the tree is established. After the tree is in the ground, put a 2-foot-diameter circle of mulch around the trunk.
The evergreen magnolia – sometimes called bull magnolia on account of its flower size – grows best in the South, which is its home. In New Orleans, you see it everywhere. It reaches a magnificent stature in that city, appearing twice as large as it does in Los Angeles.
Q: A few months ago, my friend spotted a cherimoya, from his native Bolivia, in a supermarket. We purchased the fruit and planted its seeds, which have now produced seedlings. My friend’s father insists that in order for the plants to produce any fruit, we must have a male and female plant for pollination. Yet another person has told us we must do some type of grafting in order for fruit to be produced. We’ve heard from my friend’s mother, who lives in Bolivia, that there is nothing special that needs to be done to them in order to produce fruit. I wonder if you can help us with this dilemma.
– Grace Taylor, Granada Hills.
A: I would not be able to answer you except for the assistance of David Silber – Los Angeles’ foremost horticulturist – who grows cherimoya trees in your very own Granada Hills.
The seedlings you are raising will not produce fruit like that you purchased at the supermarket. In order to grow that same fruit, you will have to graft a shoot or a bud from the tree that produced it onto one of your cherimoya seedlings.
The cherimoya produces male and female flowers on the same tree. You only need a single tree to get fruit, but you will have to assist in pollination. When the tree’s flowers open in the late afternoon, you need to insert a soft paintbrush into the male flower, extracting pollen that is then inserted into the female flower.
Your friend’s mother doesn’t understand all the fuss about cherimoyas for good reason. In Bolivia, her home and the cherimoya’s habitat, pollination occurs naturally. Either the weather there is such that breezes waft pollen
from the male to female flowers or tropical insects – not found in California – work as pollinating agents.
To be under a cherimoya tree at dusk is a unique experience. As the flowers open, they give off a sweet fragrance characteristic of the fruit itself. Cherimoyas, which may cost more than $1 apiece, have a custardy taste and texture that make you wish you had a few hanging from a tree in your back yard.
Silber, who raises this and 80 other tropical fruit trees at his home nursery, may be contacted at (818) 363-3680.