At one time or another, most of us have probably seen one of those television shows that highlight valuable works of art, antiques, or odd ball memorabilia that were found quite by chance in someone’s attic, garage, or at a yard sale or flea market.

Sally Navarette, whose backyard, cactus-like Euphorbia tree in West Covina “is taller than my two-story house” may have similarly unexpected good fortune growing in her garden.  Still, justifiably, Navarette confided that “we are afraid that if it falls it can kill someone” and, although her husband has spoken about cutting it down, she loves the tree and asks: “Is there a way to save it?”

I have never seen a columnar Euphorbia as large as yours other than those growing in the world famous cactus and succulent section of the Huntington Gardens in San Marino.   Show a photo of your plant to one of the experts there for proper identification.  Columnar euphorbias, when it comes to their classification into species, are a challenge to identify due to the ease with which hybridization of the various species occurs.  It looks like your tree could be a Euphorbia ammak, one of the more popular species and, yes, Euphorbias as large as yours are prone to toppling over so you may wish to remove some of the growth near the top to stabilize it.  Another option would be to build a support for your tree, in which case you would need to contact a fencing contractor or other expert in wrought iron construction.

I am guessing that a columnar Euphorbia as large as yours, were it for sale in a large tree box in a nursery, would probably sell for a thousand dollars, if not more.  You might wish to contact nurseries that specialize in cacti and succulents to see if they would be interested in purchasing your tree.  You could also contact tree brokers, readily located through an Internet search, to gauge their interest.  Tree brokers are always on the lookout for valuable trees, especially palms, but are interested in large tropical trees of any description.  Euphorbia trees are not widely seen, probably because they are cold sensitive, although most of them can handle temperatures down to 28 degrees.

Although columnar Euphorbia trees resemble so-called organ pipe cactuses, they differ in the source of their prickliness.  Cactus spines grow from aereoles, small fuzzy circles on the surface of cactus pads or stems.  Euphorbia thorns, by contrast, grow directly from the stem.  In addition, euphorbia thorns emerge in two’s whereas cactus spines may number from 1 to more than 10 per aereole, depending on the species.  Another distinguishing feature of Euphorbias — and all thornless Euphorbia species, such as poinsettia, are included among them — is their white latex allergenic sap, which demands long sleeves and gloves when pruning them.  Finally, the habitat of all cactus species except for one is the Western hemisphere, from Patagonia and Chile in the south, up through Central America, into the American Southwest and finally all the way up to western Canada.  By contrast, thornless, leafy euphorbia species may be found on all continents, but the thorny types are native to southern Africa and Madagascar exclusively.

I grew two cherimoya trees from seed and one has already given me a little fruit.  I have several questions about the trees.  Is the crop usually small in more tropical areas?  I can’t help but notice the terribly high price for the fruit.  I seem to have the best luck cutting them green and letting them ripen like avocados.  Is there a perfect time to harvest them?  Should I top the trees to keep an umbrella shape and when should that be done?  Is there a way to encourage more fruit?

Joan Lucero, Mission Viejo

You deserve congratulations for growing cherimoyas from seed and harvesting fruit.  The tree produces heavily in the tropics and will give you more fruit, too, with your assistance.  You need to collect pollen on the day it is produced and immediately apply it to female flower parts (stigmas) or store the pollen overnight in your refrigerator and apply it to the stigmas first thing the following morning, as soon as stigmas open, since the pollen quickly loses viability.  Application is best made with a small artist’s paint brush.  A detailed explanation of this process, with pictures, may be found on the California Rare Fruit Growers web site (crfg.org).

Chermoya fruit is expensive because of hand pollination, pruning, and irrigation expense.  In addition, fruit splits easily and stores poorly.  You are correct in harvesting them while firm and letting them ripen off the tree like avocadoes.  Cherimoyas put on lots of annual growth and fruit bearing trees should have two-thirds of previous year’s grow removed each year.  You must prune heavily in order to keep trees at a manageable height.  Withhold water starting next month in order for the tree to enter dormancy in April, which is the proper month to prune.

Tip of the Week:  Cherimoyas, mangoes, and papayas are the only commonly available fruit whose seeds grow into trees whose fruit are, as we say, true to type.  In other words, the cherimoya fruit that Ms. Lucero harvests from the trees she grew from seed would stand up in a taste test to cherimoyas sold at the supermarket.  Germination of seeds from other fruits, whether apples, oranges, or avocadoes, will almost always result in trees with inferior quality fruit.