Not Much Can Be Done About Splitting Oranges

QUESTION: I have a large navel orange tree in my back yard and the oranges are splitting and falling off. What is wrong?

--M.T., Artesia

ANSWER: Splitting or checking of citrus happens to some fruit, in some years, often causing it to turn orange and fall off well before the rest of the fruit on the tree. It is most common in September on navel oranges as the fruit begins to ripen, and according to your postmark of Oct. 8, your fruit was right on schedule.

According to Neil O’Connell, the citrus farm adviser for orange-growing Tulare County, it is a natural phenomenon, probably caused by environmental conditions, so there is little you can do to stop it (no one’s absolutely sure what causes it). The internal pressure becomes greater than the rind can handle, so the fruit splits like an over-inflated tire.

O’Connell says letting trees get too dry before watering aggravates the condition, so you can try and prevent it with consistent irrigation in summer and fall.

Another reader from Glendale had a similar complaint but added that the oranges were “split, wet and soggy.” This may be something altogether different, but it could be other problems often associated with splitting, including a fungus called black heart (Alternaria citri) that enters baby fruit, eventually turning the interior black. Splitting may also attract little dried fruit beetles. There is no control for these problems, so hope for a better season next year, and watch that watering.

Growing Fruit Trees From Pits Is a Gamble

Q: I have a small apricot tree started from a pit. When it grows up will it bear fruit?

K.K., North Hollywood

A: People are always curious what will grow from a pit or seed but there is no way to tell. Most fruit trees, from avocados to apricots, are cultivars, that is, they have been grown from plant tissue--a cutting or a bud--so they are exactly like their parent. Seeds are a complete gamble, though odds are the resulting tree will produce small, inferior fruit, more like its wild ancestors. There is also the chance that it could be quite good, but I wouldn’t take that bet, especially when it may take five to 10 years to find out.

Falling Leaves May Harm Impatiens’ Foliage

Q: Dozens of impatiens plants put in this spring are large and thriving. Now the valley oak that shades them is dropping leaves. Do the impatiens benefit from the leaves as mulch or should I keep the leaves cleared out? Also baby’s tears are nearing the impatiens. Should I expect a battle and if so which would win?

--J.S., Downy

A: If the falling leaves work their way to the ground, through the impatiens’ foliage, they’ll make a great mulch, but if they settle on top of the plants, they could cause the impatiens to rot. In that case, you may want to remove some and force the others through the impatiens foliage. Be sure to use the leaves as a mulch somewhere else in the garden since natural mulches like fallen leaves make for a richer, healthier soil and significantly happier plants. That’s one reason good gardeners frown on leaf blowers, which scatter all traces of natural mulch. Most expert gardeners believe no ground should go uncovered--every square inch should be mulched, and not with big chunks of bark or plastic, but with natural materials like leaves. It’s the natural scheme of things.

As for the baby’s tears, this won’t exactly be Holyfield vs. Bowe. Baby’s tears can be quite aggressive but are unlikely to overrun the taller impatiens. Since both like shade and moisture, they will probably coexist peaceably.

In winter, the impatiens are going to look a little ragged, but it will have nothing to do with the leaves or the baby’s tears. It’s just an awkward time of year for them. Though they can last several years, remember, they are bedding plants and are best replanted every spring, or at least every other.

Wet Spring Spelled Trouble for Roses

Q: I have three rose bushes in large whiskey barrels that were extraordinary last year but mediocre this year. They get sun from late morning through the afternoon, I water them every five to seven days and feed them monthly with a systemic product. Because of rust and mildew, I had to cut them back several months ago and now, while the rust and mildew are gone, they are droopy and the flowers’ life span is extremely brief when they used to last well over a week. Can you give me any suggestions to turn my roses around?

--N.D., Palms

A: Everybody had a tough time growing roses this year, after that long, wet spring. Mildew and rust were everywhere; even blackspot was common. Where the sun finally came out and the weather warmed, roses recovered, but in coastal areas like Palms, these diseases only disappeared late in summer.

Roses should quickly recover when cut back, even in summer, but being weakened by disease may have hurt their recovery, though picking off the affected leaves, or cutting the plants back is just about the only way to battle rust. There really are no other effective controls.

That’s probably what happened, but because your roses are in containers, I talked this over with horticulturist Tom Carruth at Weeks Roses in Upland, who I know grows lots of roses in containers in his own garden. He agreed with my guess but also suggested that the roses may need repotting, best done every two years in winter when plants are semi-dormant. If the roses are not too far gone (in that case, start with new plants), take them out of the pot, shake much of the soil from the roots, prune some of the roots, and replant with new potting soil. Once they leaf out, fertilize with a complete fertilizer high in nitrogen. Carruth uses a 16-16-16 blend and fertilizes once a month, though he says an 8-8-8 or something similar would also work. He says many special rose foods, especially systemics such as you’re using, are surprisingly low in nitrogen, the basic plant food.

He also suspects that going as long as five or seven days between waterings may be too long. Try more frequent irrigation, even every other day during the heat of summer.

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Questions should be sent to “Garden Q&A;” in care of the Real Estate section, Los Angeles Times, Times Mirror Square, Los Angeles 90053. Please include your address and telephone number. Questions cannot be answered individually.

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Garden Events

Walks, Talks, Shows and Special Sales

Saturday: A class on “Selecting, Planting & Caring for Roses,” 10 a.m., then “Dormant Pruning and Spraying of Roses,” 12:45 p.m., at the Fullerton Arboretum, 1900 Associated Road, Fullerton. Cost for each class: $8. Call (714) 773-3404 for reservations.

Saturday and Jan. 14: Orange County Rose Society pruning demonstration, 1-3 p.m., at the Civic Center Rose Garden, 8200 Westminster Blvd., Westminster; (714) 895-2860. Free.

Jan. 14: Lecture on fruit tree pruning, 2 p.m., at South Coast Botanic Garden, 26300 Crenshaw Blvd., Palos Verdes Peninsula; (310) 544-1948. $5, adults; $3, seniors and students; $1, children.

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