1st Phase Redevelopment Complete!

The grove is beautiful this time of year with the trees exploding in dark green growth, walnut-size baby avocados peeping out here and there, the buzz of bees everywhere, and a blissful breeze flowing from the west. We recently visited the grove to check out the redevelopment, the first phase of which was completed in early May. As we pulled up the drive, we couldn’t contain the excitement at seeing the transformation from a dying and barren grove to perfect rows of hundreds of baby avocado trees. Our manager, Gary Dicks and his crew, did an amazing job. Here’s what went into it.

Planting Prep

The grove was prepped and cleaned of debris. Gary engineered the new layout on high-density 15′ X 15′ spacing plan. Each spot is flagged on the center. Using a small front-end loader, tiller and hand labor, crews tilled an approximate 4′ X 4′ area to mix native soil, compost and organic gypsum. They hauled a large mound of chip material (using the old wood chips from the avocado trees we removed in the fall), placing it next to each planting site to be used for top dressing mulch after planting. A total of 262 spots were prepped.

Irrigation Design and Installation

Prepping the new lines.

Prepping the new lines.

Our 5-acre grove is split into 5 main blocks, allowing water to be controlled differently in each block. A sub-line water main runs through the property with “block” ball valves to control the water flow to each block. Then there are secondary “hose-bib” ball valves to control the irrigation lines to the trees themselves. This gives us a good amount of control to vary the irrigation to meet the trees’ needs.

New valves and pressure gauges.

New valves and pressure gauges.

Crews dug new sub-main line trenches by hand. They installed a new 1 1/2″ SCH 40 PVC sub-main water line along with new 1 1/2″ block ball valves with pressure gauges and 3/4 ” hose bib valves with pressure regulators for lateral irrigation lines. A whopping 4500 feet of 1/2″ above ground poly hose lateral irrigation lines were laid. We had permanent, in-ground irrigation previously. I believe the above-ground irrigation is used because trees may be removed in the future to reduce the density as they grow. So this will allow the irrigation to me moved and changed easily. At each planting spot, they installed poly hose bases with 8″ risers and 20 gph half-circle micro jet sprinklers. All old block ball valves were replaced throughout the grove, not just in new planting areas. Each location of a block ball valve was staked and painted yellow while each hose bib valve was staked and painted red. The crews backfilled and compacted all trenches. They then pressure tested the entire irrigation system, cleaned sprinkler heads and checked for leaks.

Planting

Before planting the trees, the crews irrigated each mound with 200 gallons of water. We planted 260 certified Hass avocado and 2 Reed avocado trees on Clonal Dusa (Merensky 2) root stock purchased from Brokaw Nursery in Ventura, CA. This root stock was chosen for its resistance to root rot. Each tree was planted in a hole large enough for the pot and then soil was mounded up 1-2 feet at the base. After planting, they spread the reserved chip material over each mound. Each tree received 8 ounces of 11-7-14+18S+Zn+Fe and was irrigated again with 40 gallons of water.

Baby trees in their mounds with new irrigation lines.

Baby trees in their mounds with new irrigation lines.

Using backpack sprayers, the crews sprayed foliage and soil with 0-28-25, 0-60-0, growmore 20-20-20 and super thrive phsphorus acid nutrient mix. This will be the first of several applications this year for the baby trees. Each tree was also sprayed with white paint to keep them from getting sunburned.

So now all we can do is wait for approximately three years before we can get our first harvest!

Meanwhile, we still have two blocks in the grove with old trees to be redeveloped. We turned off the irrigation on one block because the trees in this area are dead and cannot be salvaged by stumping. The’ll be removed. The last block of trees will be stumped later in the summer or fall. Gary determined that 6 of the trees that we previously stumped last fall are unrecoverable because they have not sprouted new growth. He cut these trees to the ground and chipped the wood. Finally, 9 trees near the top of the pad (that had previously provided us glorious shade when we visited!) were also stumped to 7′ and painted with white latex paint to protect for sunburn.

So all in all, our grove is now a hodgepodge of 262 baby trees, 62 6-month old stumped trees, 9 newly stumped trees, approximately 100 dead trees to be removed, and another 97 or so 30+ year-old tall trees to be stumped! Plus, we have a few empty spaces from the 6 trees that did not survive stumping. We got a little of everything, but this way the redevelopment (i.e. costs) will be staggered.

Feeding the Trees

Many people living in California may have an avocado tree in their yard or know someone who does. So when I have mentioned to friends and acquaintances that we have an avocado grove, their eyes light up with curiosity. They often ask how to improve their growth and production. As I understand, sometimes backyard avo trees are stubborn producers. I am no expert on avocado tree management. We have our grove manager, Gary, who is a living encyclopedia on the subject, to help advise us about how to increase production and we generally just nod and tell him to go ahead. But I can report to you all the stuff that Gary does and maybe some things might help your backyard tree.

I’ve talked about water (important for all trees) and phosphorus injections (important for trees infected with root rot) in previous posts. All trees also need food. So Gary supplements with fertilizer twice a year, once in fall and once in spring. In early April, the following fertilizer was applied:

The fertilizer Gary uses.

The fertilizer Gary uses.

  • 8 pounds per tree with 11-7-14+18S+1Zn+Fe, that’s ratios of 11 nitrogen, 7 phosphorus, 14 potassium, 18 sulfur, 1 zinc, and iron.
  • 4 pounds per tree with sulfate of potash (0-0-50).

All fertilizers in our grove were hand broadcast, but some fertilizers can be injected into the irrigation systems.

At the same time, each stumped and mature tree was injected again with nutra-mix P+K phosphorus acid 0-28-25. This is the same as the injections done in the fall (see previous post). So these are done twice a year. Injections are made into alternate limbs and trunks from the previous injection spots in the fall. Recall from the previous post that we are using a “cool” phosphorus acid that requires more holes, but results in less burn. The method is to drill two 7/16″ holes angled 45 degrees down, inject 1 ounce per tree, then refill each hole for a total of 2 ounces per tree. Below are some pictures of new and old injections as examples.

We have 68, 5-month-old stumped Hass trees and 97 tall, mature Hass trees. The same amounts of fertilizer and phosphorus acid injections were applied whether the trees were stumped or fully grown. This is because the root systems on the stumped trees are still as large as if they were full size trees.

These are management practices done for mature trees. We are in the process of planting new trees (in the next week!) to replace the ones we recently removed in the fall. The fertilizer regimen will be much different for those trees. Stay tuned for reports on that. In the meantime, spring was glorious when we recently visited the farm in early May. Enjoy the photo gallery of the splendor below.

Saving the Grove: How we either gradually go broke or find prosperity.

My husband recently reminded me of one of his favorite quotes from Hemingway.

“How did you go bankrupt?”

“Two ways. Gradually, then suddenly.”

I had mentioned before that we knew our little farm was sick. Most trees are infected with root rot (Phytophthora cinnamomi). It’s a pathogen of the soil with fungal-like attributes that was introduced in the U.S. by Australian eucalyptus trees. It prevents the feeder roots (the most important roots for water and nutrient uptake) from thriving. Thus, the trees die gradually as they are starved of water and nutrients no matter how much you try to feed them. And then suddenly they stop producing fruit, barely grow any new foliage, and start to look like gnarled trees of a creepy forest.  Click here for more info.

Infected soil. Look for the cinnamon-colored roots.

Infected soil. Look for the cinnamon-colored roots.

During a walk around the property with our manager last month, Gary showed us first-hand what a root rot infested “dead” tree was like compared to a healthy one. As he removed some of the leaf brush covering the ground of a sick tree, he could easily pull up handfuls of dark, wet soil that had minimal root systems. The dying roots were all brittle, dark and covered with a cinnamon-like color (thus, the pathogen’s namesake). Beneath a healthy tree, he could barely get his fingers to dig just a few inches below the surface, there were so many roots. Scratching the skin off the roots revealed a bright white interior, a sign of a strong, healthy root.

A little blurry, sorry, but a healthy feeder root.

A little blurry, sorry, but a healthy feeder root.

The problem is that of the 400+ trees on our property, probably less than 25% are healthy. And it probably won’t be long until the healthy ones get infected. So how do we save the grove? Replant with resistant rootstocks, or stump the trees. Stumping is the process of cutting down the trees to about 6 to 7 feet high, whitewashing them, and waiting for them to come back. Avocado trees are magical in that regard. They’ll produce as soon as a year after being stumped and may reach full production again 3 years after. Stumping often does the trick, allowing the trees to become healthy enough again to beat the root rot, but it doesn’t necessarily prevent them from being reinfected. And while stumping will allow the trees to produce a little quicker than replanting, it is likely that they would only continue producing a yield for another 5 years before you have to restump or replant it.

So we’ve begun a “redevelopment” plan that will take several years to implement that involves both stumping and replanting. We just finished the first phase a couple weeks ago. Ninety-three dying trees were cut to the ground and chipped. Another 68 somewhat healthier trees were stumped to 7 feet. We are prepping to replant 125 Dusa and 50 Toro Canyon clonal hass avocado trees that will be resistant to root rot. The replanting will happen in the spring. The hope is that the few remaining healthy trees will partially cover costs while we wait for the stumped and replanted trees to produce. And then we’ll finish replanting the remaining trees.

As my husband was saying, the Hemingway quote is applicable to anything in life: our grove, health, relationships. Life is full of trials that take a lot of tenacity and deliberate action to stave off the gradual decline. But as I stood above the demolished and stumped trees, I couldn’t help feel a shiver of hope and excitement, like renewal or birth. I watched my kids climb the mounds of chipped wood pretending to “conquer” and my lips curved upward. We are building something together as a family. If nothing else, with all the trees gone, we now have a fabulous view! Check out the series of before and afters below and in my photo gallery (unfortunately, I took these pictures and not my sister!)

“Only those who attempt the absurd can achieve the impossible.”

– Albert Einstein

Lots of sad looking trees.

Before: Lots of sad looking trees.

Looking down the hill in the same location after removal. More of our healthier trees are down the ravine.

After: Looking down the hill in the same location  More of our healthier trees are down the ravine.

Before: Gary and Aaron walking up the drive.

Before: Gary and Aaron walking up the drive.

After: The same drive now surrounded by stumped trees.

After: The same drive now surrounded by stumped trees.

Before: X marks removal.

Before: X marks removal.

After: View to the west.

After: View to the west.

Before: Jack shaded.

Before: Jack shaded.

After: Not so much shade anymore.

After: Not so much shade anymore.

Close-up of the stumped trees.

Close-up of the stumped trees.