Fruit Thinning

We've just about finished the tedious task of thinning excess fruit from the trees. Thinning is a vital step in fruit tree care that many backyard gardeners neglect, while others may not realize that it should be done at all. But given the right growing conditions most stone fruit trees will set far more fruit than they can support. Unless much of the excess is removed, both fruit quality and tree health will suffer. Trees that typically need thinning are apricots, peaches, plums, pears and apples. Cherries, figs, persimmons and citrus usually do not.

Here are the benefits of thinning:

• Thinning matches the tree's energy with the amount of fruit it has to nourish. A tree has only so much carbohydrate stored in its roots, so when too many fruits compete for this nourishment they all end up small and flavorless.
• Thinning reduces disease and insect damage. Crowded clumps of fruit offer hiding places for damaging insects, which can then damage all the fruits in a group. Crowded fruits also stay wet longer in damp weather, encouraging mold and fungus problems that can quickly infect all adjacent fruit.
• Excess fruit weighs down branches, especially when trees are not adequately pruned. This often leads to broken limbs.
• Crowding shields fruit from sunlight, decreasing fruit color and flavor.
• Thinning is an opportunity to remove smaller, deformed or damaged fruit so more of the tree's energy can go into the remaining perfect fruit.

As we admire small green fruits early in the season and dream of biting into a ripe peach or apricot later on, it can be really hard to pull fruit off. But as with pruning, this is not a time to be squeamish. Apricots should be left no closer than 3-4" apart, and peaches no closer than 6-8". Fruit at the ends of long branches should be thinned even more heavily to avoid breakage in a wind storm. On a heavy year we will often need to remove 90% of the fruit from a tree, leaving the ground littered almost solid with small green fruits.


Apricots before thinning . . .



Timing of thinning is important too. Most trees will self-thin to some degree; at an early stage some fruits will yellow and drop off on their own, so it is important to wait for this to happen before manually thinning. But once that happens we like to thin right away, so the remaining fruit will get the most benefit. Leaving too much fruit on also starves the tree which then reduces next year's crop, so it is always better to thin more, not less!



and after the first thinning

 Thinning can be done by knocking with sticks, but we prefer doing it by hand. It's a lot more work, but gives us much better control and hence more benefit. Ideally the smallest fruit should be removed in favor of the largest.


Peaches before thinning . . .



We will typically thin twice, the first time leaving a few too many to cover our bases in case a bad hail storm or wind should damage much of the fruit. Then after 2-3 weeks when the fruit has sized up a bit more we go back and get more agressive.

and after the first thinning

The pictures at right show a typical before and after first-thinning look at cots and peaches. The second thinning will remove even more fruit. It hurts to do it, but always pays off in fruit size and quality. After 40 years I don't remember ever thinking we thinned to heavily.

Birds of Spring

Male Bullocks Oriole

This time of year the air is a symphony of bird sounds as mating season gets into full swing. Whether calling to a mate, announcing their territory, or just singing for the fun of it, birds are especially vocal right now and are a joy to watch and photograph.

We tend to put birds into categories based mainly upon their diet:

• Birds of prey (hawks and owls) get a totally positive rating for their service eating varmints.
• Insectivores and seed eaters (various flycatchers, doves, goldfinches, quail, robins and hummingbirds) get a positive rating for eating insects or seeds and mostly avoiding orchard fruit.
• Voracious fruit eaters (blue Jays, orioles, house finches, starlings, sparrows) get either a mixed or negative rating due to bad manners, eating too much fruit, and generally being a pest. Of course not all birds are necessarily completely good or bad. Our Bullocks orioles are about the most dramatically colored birds around and always a treat to watch, but I'd like them better if they didn't eat our fruit.

A barn owl peeks out of his home

Owls are some of our favorites, especially barn owls. These beautiful creatures have our undying gratitude for solving our serious gopher problem some years ago. Barn owls nest only in cavities (hollow trees, old buildings, or man made nest boxes) so several years ago I installed several boxes on our property and around the area to entice more owls to settle here.

Seven young barn owls in their nest box

Now we enjoy the comforting sounds of barn owls at night year-round, knowing they are on the job keeping rodent pests in check. You can see more of our owl photos in this post.

Besides barn owls, great horned owls, screech owls, and burrowing owls inhabit the neighborhood. And a variety of hawks take over varmint hunting duties during the day.





A male bluebird sits outside a nest box

Western bluebirds and tree swallow populations are also increased by nest boxes. We have several boxes around the orchard that house nesting pairs every year. Both birds eat mainly insects, or small wild berries in winter.



A bluebird enjoys a drink from the birdbath

As we have encouraged beneficial birds with nest boxes, bird baths and a diversity of food sources, we've noticed an increase in their numbers compared to pest birds. But we still have plenty of fruit eaters that require elaborate bird scare contraptions during harvest season - more on that when the time comes. In the meantime we're just enjoying the sights and sounds of our feathered friends.




A goldfinch frolics in the bath

Acorn woodpecker

A dove sits patiently in her nest

Promoting Balance in the Orchard

It is now early April and we're nearing the end of a very wet rainy season. The cover crop on the orchard floor has flourished, growing tall and dense. Starting in early winter the thick growth of bell beans, vetch, field peas and mustard helped to capture rain runoff and prevented erosion.


Once in the bloom phase the cover crop has attracted and nourished many types of beneficial insects which help keep harmful pests in check.

Just about any flowering plant will attract insects and other creatures both good and bad. The key to natural pest control is to promote a diverse biological environment so natural predators can help keep harmful insects and animals in check. In the photo at left a bell bean plant is infested with black aphids. These aphids do not attack fruit trees, but they do attract lots of green lacewings and lady bugs, which are then present to control the green aphid that does infest fruit trees. And sure enough this plant is covered with dozens of lady bugs and their larvae (the larvae are the alligator like creatures).

Another benefit of a good cover crop is natural soil fertility. Besides mining the soil for deep minerals, the legumes in the mix have the wonderful ability to add nitrogen to the soil. So called nitrogen fixing bacteria in the soil colonize the roots, forming the white nodules shown at right. These bacteria live in a symbiotic relationship with the plant, capturing nitrogen from the air. When the plant dies, excess nitrogen is then available for other crops, in this case the fruit trees.

But as the rainy season ends it is time to conserve as much soil moisture as possible to see the trees through the dry months ahead. So I've just mowed down the cover crop to stop it from drinking up any more of winter's rainfall. I use a flail mower which chops the growth into a uniform layer of mulch. This residue will soon dry to a straw color, reflecting sunlight and keeping the tree roots cool while reducing evaporation from the soil surface. The decaying roots and mulch will now be digested back into the soil in nature's continual process of cycling nutrients from plant to soil to plant again.

A Successful Bloom!

We're now basking in the afterglow of a wonderful heavy orchard bloom, thankful that mother nature and our trees have come through once again - no devastating hail storms or severe freezes to ruin the blossoms, but cooperative weather that let the trees burst out in glorious bloom.

Apricots in full bloom

Peach trees at sunrise

 

The flower buds formed during last year's growth, then sat dormant overwinter waiting for the required 400 or so chilling hours (hours below 45 degrees) needed to make them viable. Once the required chilling hours have been met, the next hurdle is avoiding extreme cold during bud swell, bloom and beyond. So far so good.

Bristling with little pea sized fruits, the trees are now sprouting this year's leaves as they transform from winter's dormant skeletons into vibrant bushy fruit factories. Notice that the tiny apricots already show the beginnings of that beautiful red blush that makes them drop-dead beautiful when ripe.

For the next few weeks the main hazard for apricots are fungal diseases, a problem made worse by wet weather. We try to minimize this by spraying a copper compound several times during the dormant season.

What's that, how can you be organic if you spray? Well, the question is not whether you spray, but what you spray. Spraying is just a method of applying something to a plant. We use a sprayer to apply many things to the trees: fish emulsion and kelp for foliar feeding, bacillus thuringiencis (a naturally occurring bacterium) to kill leaf eating caterpillars, a light colored clay powder to reduce sunburn on walnuts, a natural soap solution to control aphids, and a copper product as a fungicide. The key is that any "input" to our farm must be labeled as approved by the Organic Materials Review Institute (OMRI). Generally that means only non-synthetic ingredients. Copper is a naturally occurring (and necessary) soil nutrient, not a synthetic chemical, and the particular product we use is OMRI approved. But first and foremost we try to promote a condition of balance in the orchard where diseases and pests are kept in check by natural enemies. More on this topic next time . . .

Bloom Time

In a way, bloom time is a period of climax in the orchard, when the benefits of pruning, composting and cover cropping launch this years fruit crop. This regular routine of pruning and soil enrichment, together with kind weather, almost always delivers a heavy bloom in our trees. So this is always a season of optimistic anticipation of healthy blooms and a good fruit set.

So far this season has been good, nice and wet but yo-yoing from warm to cold and dry to wet, in all combinations. So we've had a start/stop in the bloom where some flower buds  opened and set fruit in our warm early February, but most stalled when the weather turned unusually cold

This photo shows buds in several stages on one stem: the red "popcorn" stage buds just ready to burst open, the white petaled fully open flower, and the lower bud after pollination and petal-drop, with a tiny apricot forming inside. Those are the ones we like to see.

Meanwhile the cover crop is maturing into a lush mini-forest of green matter. Right now the orchard floor is an absolute jungle of microbes, fungi, earthworms, insects, and birds. The bell beans, peas and vetch loosen the soil with deep roots, bring soil minerals to the surface, capture nitrogen from the air, attract beneficial insects and pollinators, prevent erosion, and hold rainfall on our slopes. Later it will be mowed, left to break down and feed the microbes that then feed the soil, which then feeds the trees.

Bell beans blooming

I'm convinced that one of the major benefits of a cover cropped, mowed-not-tilled orchard is the habitat it provides to beneficial insects. There will always be opportunistic bad bugs, but attracting a diverse insect population helps to keep things in balance. The bell beans in the cover are just popping out, and are alive with lady bugs, green lacewings, and bees, all doing their good deeds. Next the field peas will bloom and finally the vetch, providing an ongoing habitat for beneficials.




Mustard is another great part of the mix, with a great root system and a heavy load of pollen. Native bees, bumblebees, and honey bees all like to come.

So, for the next three weeks we're anxiously waiting to see how the fruit set turns out. We'll be hoping for mild dryer weather during peak blooms but also for more rainfall to store in the soil to get us through next summer. We're optimistic!

Pruning Season

This is pruning season in the orchard, the time of year when I give all the trees their annual haircut. Pruning accomplishes several things: removal of dead and weak growth, opening up space for ladder access and to allow sunlight and air circulation into the lower parts of the trees, and limiting the height and spread of the trees.

Without regular pruning most types of fruit trees lose vigor and become too tall and cluttered. Stone fruits especially require heavy annual pruning. The fruit bearing shoots only live for 2-3 years, so pruning stimulates constant growth of new fruiting wood. And left unpruned, most trees will get so crowded with growth that the lower and interior parts become too shaded. The shaded areas then die back and stop producing fruit, leaving only the top and outer branches bearing. Excessively long branches are also subject to breakage.

So pruning season is time for some tough love, where each large tree will receive hundreds of cuts. There is an art to pruning to get the best results, but in reality any pruning is better than none. The heavier the pruning the more new growth results, so over time wood removal is the best way to create the size and shape of tree you want, while keeping it healthy. The photos below show one of our 35 year old apricots before and after pruning.




Large apricot tree before pruning

 

The same tree after pruning



It's Persimmon Season!



Hachiya Persimmons



It is now early November and after a long dry summer we are enjoying all things Fall - the cool weather, the hills turning green, the smell of damp earth, and now, ripe persimmons. We have two types, the heart shaped Hachiya and the tomato shaped Fuyu. Both are delicious but very different in their ripening requirements.



Unripe Hachiyas have very high tannin content and taste terribly astringent in that stage. They must be allowed to ripen completely until the skin is translucent and they are as soft as water balloons. When fully orange but still firm they can be picked and allowed to finish ripening off the tree. (Tip: Enclose them in a paper bag with an apple or banana. These fruits give off natural ethylene gas which speeds ripening.) When fully ripe they taste like fruit syrup, super sweet and delicious. You can use them in persimmon cookies or cake, or just spoon the gelatinous pulp over oatmeal or ice cream.


Fuyu persimmons


Fuyus on the other hand can be eaten when still crisp-firm, or left to soften further. Once fully orange they are very sweet and can be eaten like an apple, sliced up into Waldorf or green salads, used to make chutney, or sliced on top of cereal or pancakes. One of our favorites is a simple fruit appetizer of peeled and sliced Fuyus sprinkled with fresh lime juice. Since the persimmons are sweet and very low acid, the addition of the lime juice really sets them off. This dish always amazes guests!



Sliced Fuyus and lime

















Cover crop update

Timely fall rains and warm days have provided perfect conditions for the cover crop seed to sprout in the orchard floor. With adequate winter rains the seedlings will become a tall dense stand of nutrient rich plant matter by next spring. We will then mow it down to cycle it back into the soil for grow-it-yourself fertilizer. In the meantime we watch the weather forecasts hoping for more rain.