Although the land in Brentwood, California is some of the most fertile in the country, when Farmer Al began on a 13 acre plot here in 1976, much of the soil had been depleted by monoculture. That meant that if he had continued to grow a single crop without replenishing the nutrients it soaked up from the soil, the land was at risk of eventually becoming barren. 

Over the next 45 years, Farmer Al and team made sure to support the balance of minerals and biology in the soil and to care for each tree. Now, they produce the sweetest fruit I’ve ever tasted.  But how?  I found myself asking when I began working here this May.  How do they do it?

Every day I learn something new about the laborious and highly-adaptive process that is growing fruit. Thrust into the ebb and flow of harvest season here (the busiest time of year on the farm by far!) I have an ever-growing appreciation for what each beautiful piece of fruit takes. That peach you have to eat over the sink because it’s so juicy and delicious—that doesn’t come from simply being a farm that doesn’t use toxic chemicals on the trees or in soil. I’m learning it’s ohhh so much more than that. 

1. We pick our fruit when it’s “ready to eat” ripe.

For the home grower with just a few trees, letting the fruit fall when it’s ready might sound like a simple and obvious way to ensure tastiness. But if you have thousands of trees, that's… harder. 

The majority of farms (both conventional and organic) pick their fruit a bit green. That works well when the fruit needs to travel long distances—it’s less likely to be damaged or rot in transport. But there’s a downside: a fruit’s sugars stop developing once it’s off the tree. If you pick on the early side, you’re sure to lose some flavor.

Farmer Al and the Frog Hollow harvesting team let their fruit “tree-ripen,” meaning the sugar and acid levels in the fruit reach an optimal level for eating before the team picks it. It’s tricky though! The timing is dramatically affected by weather and varies by fruit variety. And there are risks to waiting too long. Let the Leah Cot apricot sweeten up on the tree past perfect ripeness and you lose that gorgeous acidity. Picking fruit ripe also means it’s more delicate, so the team must carefully handpick each piece. 

All in all, knowing when an orchard is perfectly harvest-ready is no simple task—it’s both a science and a gut-sense. Luckily, Farmer Al has both. After 45+ years of farming he can judge if a particular orchard is ready by the look and feel (maybe even smell!) of the fruit. Farm Assistant Rachel Sullivan brings another great tool into the mix: measuring sugar content, or what we call “Brix” level, using a cool science gadget called a  refractometer. For some context of what “Brix” looks like in practice, think about this: The average Brix level for an apple you buy in store is 10.* Can you picture it? Close your eyes and imagine the taste. 6 for an average quality tomato, 7 for a mango, 9 for a blueberry, and 10 for a banana.* If you want to get a little technical, you could say that one degree of Brix equals roughly one gram of sucrose in 100 grams of liquid. It’s important to keep in mind that while Brix does tell you a lot about sweetness (helping us on the farm evaluate when fruit is ready to pick), it doesn’t take into account anything other than sugar content, like acidity, which is very important when it comes to complex and delicious flavor.

Rachel measuring Brix with the refractometer

Right before the crop comes off the trees, Rachel takes a random sample of 5-10 pieces of fruit from the orchard to test. She slices them and squeezes the juice from each one onto the refractometer. Looking inside the tool, she sees a scale from 0 to as high as 35 where the sugar level in the juice will register. Rachel records the numbers for each piece of fruit she tests, takes the average and then has an idea of where the crop’s sugar levels are as compared to last year. Farmer Al consults her data as he decides when to pick a particular orchard. If the Brix level is lower than expected, they decide to leave the fruit on the trees for a few more days. If it’s higher, they exclaim in delight and invite whoever’s in the vicinity to taste it. (I’m lucky enough to often be nearby!) Each variety of apricot, cherry, nectarine, peach, pluot, and pear in the orchard have their own optimal Brix range. And with years of data to compare it to, Rachel and Farmer Al can easily tell whether a particular crop is where it should be. Brixing also lets the team experiment with planting new fruit trees. Farmer Al can make an informed choice about whether to plant more of a new variety depending on if the crop grows well in the soil and if it’s up to Frog Hollow flavor standards.

Rachel and I hosted a fruit tasting at Brentwood Elementary School this past week and the looks on the kids’ faces when they took a bite of our Goldensweet apricots was a delightful combination of pure shock and joy. Ask anyone what they think of Frog Hollow fruit and they’ll talk immediately about the sweetness. 

Looking at the Brix data is also its own sort of delight. Today, I Googled what was considered “normal” Brix levels for the kinds of fruits we grow. If you sample a random selection of fruit available in grocery stores across the US and compared it to the average Brix levels of our fruit last season, this is what you see:

 This year, our Brooks cherries averaged 25 in the early season and our Goldensweet apricots are coming in at 21 now!

2. We care for our ecosystem by cultivating the nutrients in our soil.

Even if all farms were to let their fruit ripen a little longer, outstanding Brix levels don’t just magically happen. Part of what makes the trees so happy here is that we don’t dump toxic chemicals into our system to manage fertility. Instead, we work hard to balance the nutrients in the soil using naturally-derived materials—meaning whatever minerals a single tree absorbs from the ground, we make sure those minerals are replenished. 

Plants require a few key macronutrients (nitrogen, phosphorus, calcium, sodium, and potassium) as well a number of other micronutrients (magnesium, iron, and zinc) in order to grow and we carefully monitor their levels using soil testing, adjusting them when necessary. Conventional farms often apply heavy amounts of synthetic fertilizers to put those nutrients back into the soil, which might have adverse consequences on the environment (ex: nitrogen leaching into groundwater). We do not. We apply carefully calculated small doses of naturally-derived fertilizers (ex: fish hydrolysate for nitrogen and gypsum for calcium) right around the base of the tree. 

We also apply tons of our good old “homemade” compost. The compost is rich in microbes—tiny soil creatures that mineralize nutrients for our trees to soak up. The happier and more plentiful the microbes, the happier and healthier the trees. The conscientious recycling of our decomposable resources into compost and then back into the soil is part of what it means to be a regenerative farm (rather than simply an organic one). We also plant “cover crops,” which are plants whose roots provide structure to the soil and homes for microbes. They also hold some of those nutrients and moisture that our trees like to suck up. And we allow for beneficial weeds and grasses to grow in our orchards, which we cut by hand and leave on the orchard bed as a layer of protective mulch. This mulch protects the soil from the blazing sun, helping the trees absorb water even when it’s so hot. As a bonus, that helps us conserve water.

Frog Hollow's compost piles

3. We take extra care with our trees all year round.

It takes a year of care to make one peach. And with 60,000 trees, it’s kind of hard to wrap my head around what that looks like. You can roughly break it down by season. After harvest, in the fall, we focus on ground care—fertilizing the soil, applying compost, planting cover crops, and more. During the winter our tree team prunes the trees to get rid of dead branches and to make sure sunlight reaches the inside leaves. That helps the tree grow efficiently. Then, throughout the spring months, the team thins the trees, meaning we hand remove some of the fruit that a tree is producing early on in the season so that the fruit that’s left can soak up plenty of nutrients. Frog Hollow also takes an integrated approach to managing pests, meaning providing habitat to owls (who help us keep the ground squirrel and gopher populations under control) or releasing “good” bugs to eat the “bad” bugs in the field—natural ecosystem management processes (rather than synthetic/toxic) that could all be their own blogs! All this takes time, effort, and hard work. But the taste is worth every minute. We hope you agree. Like I said, it takes a year to produce that single peach. But Frog Hollow is up for the challenge.

Thinning a young tree