Articles written by Darryl McCullough (unless otherwise noted)

Sunday, December 27, 2015

Message Received

It's a little more than a year since the passing of Pete Ray, one of many who made the MRFC the great club it is today. Our paths only crossed for a couple of years near the end of his life, but I learned a lot from him. He took me on a personal tour of his fabulous collection of fruit trees, and last year he gave me several trees and shrubs that I hold special.

Pete also encouraged me to take over his blog, despite my status as a fruit tree beginner. Some days I still feel like one, but the challenge of coming up with a weekly something that somebody out there might find worth reading has been a great motivator for me to learn and keep learning.

Christmas is a time when most of us think back to earlier days, and remember the people we knew along the way who gave us something we still carry inside. Even though I won't ever forget these folks, I often receive little reminders from them, and last week Pete sent me this one on a hibiscus plant that came from his collection. There are many beautiful flowers, but I don't think there are any more elegant than a hibiscus at that perfect moment.

Sunday, December 20, 2015

From Here To There

For various reasons, I've transplanted quite a few trees and shrubs this year. I began with misgivings, but to my relief it has generally worked out very successfully.

Back in February, 2014 I planted a Tithonia rotundifolia, the Mexican Sunflower, in my east mango grove. It's a nice ornamental and also a good nutrient recycler, a vigorous grower of long, thin branches of soft wood perfect for the mini-chipper. But I hadn't realized just how vigorous a grower it was, and before long it was creating a shading and crowding problem. So in February of this year, it went to a new home under a big live oak. The moved cost it a lot of roots, but it's a tough plant and after a droopy week, it took off again. It's in the middle of this photo, flanked by a young floss silk tree on the right and a pair of seagrapes on the left, and with the oak behind it.

This “Raggedy Ann” copperleaf had been losing badly in competition for light and water with a nearby oak tree. It had partially defoliated and looked destined for the chipper. At the end of June, I tried it in a terraced spot near the driveway. Six months later it's happy as can be, showing off its unique foliage every time we pass by.

Here are a couple of Grewia asiatica bushes, often called Sherbertberry or Phalsa. Somewhere in the world people are enjoying sherbertberries, I'm sure, but mine have all tasted terrible. So last June the lanky plants lost their sunny irrigated spots to two grafted dark-fruit Surinam cherries. The spread-out root systems of the Grewias were mauled when I transplanted them to a morning-sun location along the east fence. Both bushes almost completely defoliated, but after pruning back they quickly leafed out again. In this somewhat dry, shady spot, they have grown slowly but looked healthy, even producing a few more of their unpalatable fruit.

These are the Surinam cherries that took over the spots vacated by the Grewias. So far they've produced a few tasty fruit that I've taken off quickly to avoid attracting the climbing raccoons who live in the adjoining woods. And the smaller one is triply staked for extra protection.

This wampi seedling was occupying a sunny, irrigated spot. It may be a while before it produces, and the wampi fruits I've eaten were very resistible, so in November it went over to the east side to live under some oak canopy. It's taken the move in stride, and should green up with some nitrogen feeding in the spring.

Here is the Angie mango that took over the wampi spot. It's the only mango variety I have two of, so I used this one in this space next to the woods. That way, if the critters grab a lot of its fruit I'll still have its twin in a safer location. Or maybe they will just develop a real craving for Angies...

This winter-dormant frangipani has a nice shape and pretty dark pink flowers, but certainly didn't need the irrigated space where I naively planted it as a broomstick more than three years ago. Now it's terraced near the bottom of the septic drain field hill. Perhaps a little risky to the field, but I figure it will send most of its roots downhill, and provide a nice drought-tolerant ornamental in an otherwise useless spot. Its former location is ready for the Jin Huang mango on my porch to be planted there next spring.

These two little sapodillas, an Alano and a Molix, were an unsuccessful experiment to see whether they could do well near some oak trees on the east side. Competing for sun and water, and occasionally molested by raccoons, they were struggling. The raccoons even killed a larger Oxkutzcab sapodilla nearby, so it was high time to clear out. Seen here a week or so after transplanting to prime locations, they already looked happier. To their right is a Campeche variety sapodilla that produced its first fruit just this year, and center rear is a Sweetheart lychee that really wants some cool weather to help it fruit next June.

That's not all, there's more. We'll see it in a future post.

Sunday, December 13, 2015

The Heat Is On

Every fruit tree grower, and most everybody else, knows that it's been unseasonably warm in Florida. Throughout our state, in fact, it was the warmest November ever recorded, and with today's ten-day predicted highs and lows both far above average, there is no letup on the horizon.

The good news is that we're getting extra growth from young trees, like this vigorous December flush on my young No Mai Tsze lychee tree. The bad news is that annual cycles are being disrupted. My fig trees, which should be dropping their leaves for the winter, are merrily budding. Friends report blueberry plants heavy with fruit. You can probably supply your own examples.

For a dooryard hobbyist like me, a bad blueberry or lychee crop next year is not a big concern--- though I feel for commercial growers out there who may be facing major losses. My main worry is that we're set up for the tropical fruit tree grower's nightmare--- trees in active growing mode hit by a sudden freeze. I've meditated to Ma'am Gaia more than once about this matter, though I've had to admit that conditions bad for my kind may be perfect for other species, and that she might not have reason to favor these upright-walking social primates who have been doing so much damage lately.

Key to the upcoming winter is an El Niño that is at least the second-strongest on record. This band of unusually warm water in the Pacific equatorial region affects the jet stream and other determiners of our winter season. A lot has changed (notably polar temperatures) since the previous largest El Niño twenty years ago, complicating the already-difficult task of predicting its effects. The best guess from NOAA is a wetter-than-usual winter, and a fair chance of a cooler one, though perhaps counterintuitively, “strong El Niño’s often mitigate the chances for freezing temperatures.” In this case, it's wise to take “often” to mean “not always”.

So even though it still feels almost summery out there, it's high time to make sure all your favorite freeze-protection methods are in place and ready to go on short notice. Just in case the warmer-than-usual temperatures don't last for the next three months.

Sunday, December 6, 2015

Finally, Real Progress on Greening?

I'm still getting some good oranges off the mature trees left on our property by a previous owner. But last spring I had to put two Minneolas and a never-did-produce Valencia out of their misery, and as limbs die back, the remaining relics get smaller every year. They form far more fruit than they can possibly ripen in their weakened state. Most fall early or succumb to one assault or another, but a few make it through. And remind me that a good orange is among the finest of fruits.

The biggest, baddest of citrus diseases is, of course, the relentless HLB or citrus greening disease that continues to devastate the Florida industry. For years the news on greening has been dire, but Texas A&M researcher Erik Mirkov has developed greening-resistant trees by transferring spinach genes that produce antimicrobial proteins.

Now, scientists Jude Grosser and Manjul Dutt at Florida's Citrus Research and Education Center have used a gene from the mustard family to produce greening-resistant Hamlin and Valencia orange trees. Their September article in the prominent open-access scientific journal PLOS ONE details the work.

Test results of their trees appear similar to those reported by Mirkov. In field trials in groves heavily infested with greening, some lines tested positive for greening at some points in the trials, but greening-free later. Three lines tested free for the entire 36 months. Laboratory trees exposed to continuous attack by infected citrus psyllids exhibited similar resistance.

The work would have to be repeated for other varieties and citrus species, but this could be avoided if the method can be adapted to produce rootstocks that impart greening resistance even to non-genetically-modified scions. In addition, the authors speculate, this “could potentially be more acceptable to consumers than transgenic citrus scions.”

For both the Texas and Florida programs, considerable further development and testing are required, and it will still be years before these trees are available to the public.

Is victory at hand? Not yet. The trick now is to “stack” the mustard gene with another gene that works by a completely different mechanism. For such a doubly protected tree, it would be far more difficult for HLB to adapt to overcome the defenses. Then we win. At least until the next scourge spawned by the vast monocultures of industrial agriculture.