Wednesday, August 13, 2008


A - "Keeping it Simple"
When fruit is dropping and birds are feeding in the tree, chances are you're approaching harvest time for that crop. Then apply the taste test. These are perhaps the easiest ways to determine harvest time in the School Orchard, with its multiple varieties of trees.

B - "More in Depth"
For the Apples, you should be able to indent the skin and flesh with your finger nail, and when you cut it open the seeds should be dark brown or black. If seeds are still light color, you're not quite ready for harvest. If there is good sunlight on the apple, and the nights are cold, some red color will still develop.
Be careful when harvesting the Apple! Lift it with a little twist. It should  separate at the stems abscission zone (that's the little wider area near the tree end of the stem). If it doesn't come away easily... leave it on the tree. The risk is breaking the little gnarled "Fruiting Spur." In Apples, the Fruiting Spur should bear fruit for 10 or more years. Some instruction  for the students and helpers will keep your Apple tree bearing for years, otherwise you'll have to wait for another Spur to develop! Apples ripened on the tree taste great. Let the students have a harvest party, and eat the apples right there.
"Asian Pears"  (e.g. Chojuro, Shinseiki) can be harvested like the Apples, and eaten right off the tree. Use the same "ripeness" criteria. They will usually turn from green to a yellow buff color, even almost tan to russet. And for Pears.... treat the Spurs the same as Apples. They wont last quite as long, but they set fruit at the same spot year after year.  The most frequent harvest problem in the School Orchard is that kids pick the fruit prematurely, and "pull" the apple or pear down, breaking the Spur.

"European" Pears (e.g. Bartlett) can be picked when they are full sized, but still green and firm. They should then be stored in a refrigerator for at least a week,  then taken out and allowed to ripen. These are not eaten "tree ripe." When ripened on the tree, they tend to get "mealy."
Your Stone fruit (Peaches, Plums etc.) are probably all harvested by now, but if not, they should be allowed to ripen (soften) on the tree and eaten fresh.  The Persimmons should be ready from October to November, in most regions. Both common varieties should be bright, shiny Orange in color. The flat, squat shaped ones, the "Fuyu," should be eaten when they are firm, like an apple. The acorn shaped "Hachiya" must be almost custard soft before you give them a bite! (but they can ripen off the tree) If you mix the two up you're in for a mouth puckering surprise!   Persimmons should be harvested by cutting the stem (there are harvest clippers that are shaped like your two fingers when you make a cutting sign.

Thursday, August 7, 2008

Fall Fertilizing

A - "Keeping it Simple!"
Right after Harvest, You can give the trees another application of Fertilizer similar to our Spring/Summer suggestions. Or, spread about 2 to 5 pounds of compost per tree in a 6" band around the drip line, under the mulch. (Keep away from the Trunk!)
If it's later in the fall: sit back....enjoy the view of the School Orchard, do nothing, think about the pleasures of Dormancy...... Lucky trees!  
B - "Hey, wait a minute what's going on here!" 
All that food and stuff from the leaves (starches, carbohydrates, sugars, pigments, water etc. etc.) has been retrieved (sucked back actually) by the trees..... before they actually dropped the leaves. All that food is stored in the trunk and roots. In the Spring, before there can be any energy production from leaves, the "sap" will come rushing up from storage to fuel the whole works. Vermonters will tap off some as "Maple Syrup" for Pancakes, and Southeast Alaskans will tap off "Birch Syrup" for their biscuits.  It's sweet 'cause it's loaded with sugars and Energy.
Don't worry there will be plenty to do later, but in the School Orchard more Fertilizer is usually not needed! The exception is:
If you've noticed a deficiency (yellow leaves during mid-summer), post-harvest is a good time to correct the deficiency.
Short of doing a leaf analysis, the Compost application is your best shot at fertilizing and correcting the nutrient deficiency.
Hint: Supermarket Chains in Los Angeles County have their day old and wilted Produce professionally composted. Vons especially has been very happy to donate compost to our School Gardens and Orchards. The Compost is Superb!! It's arranged through the Manager of the neighborhood Market in the School's community. It's likely done by chain Markets throughout the State. Their objective is to sell the Compost to Organic Farmers. A neighborhood manager can donate a load to your School Orchard. Be grateful... and post a sign thanking them.... the school garden and orchard can be a real link between school and community.

Fall Pruning

 A - "Keeping it simple!"
 August, (and perhaps the first few weeks of September) is the best time to prune the Apricot and Aprium trees.
 With your Pruners and Loppers remove any "suckers," cut out Dead, Deformed, Damaged, and Crossing shoots and branches.
 Remove the "Water Sprouts." These are the paradoxically very green and healthy looking shoots, that you might think are "good"  to save..... they're not! They usually grow from interior branches, are this years growth, and grow straight up to the sky with no branches (they will rarely have any fruit!)
 The lateral branches (reach out with your arms) will have the shoots with fruiting spurs. For the ones that grew this year (green bark) visually divide the shoot into four sections, starting from the origin,.... cut off the outermost one, of the four sections (that is: reduce the length by 20-25% of the shoot's length).
 Try to cut the shoots or branches at a point about 1/4 inch out from a bud or node. It's best if the bud (node or shoot) is pointing in the general direction that you want the branch to grow (e.g. not pointing down.... or towards the central/interior area of the tree). If you have to  remove a branch entirely, make the final cut just outside of the little "collar" where the  Branch originates from the Trunk. Don't leave  a "stump."   
 B - "More in Depth:"
 Post harvest, or late "summer" pruning is particularly useful if trees have been growing too vigorously, and are getting out of control (too high).
 Summer and post harvest pruning has a modulating effect on tree growth. On the other hand: Pruning after leaf drop is a great stimulant to spring growth!
 APRICOTS  should NOT be pruned any later than early September. So this is the last time you can prune them before mid-summer next year.
 Apricot pruning wounds are subject to a disease (Eutypa Dieback) the organism is spread by rain. The pruning wounds need 6 to 8 weeks of dry
 weather to properly heal.
 The Water Sprouts can be thought of being like your Appendix.... it probably once did.... but no longer has any real function. Probably genetically left over from when the tree had to "get up there" to compete for light from its surrounding trees. These shoots rarely if ever bear any fruit.
 You also want to remove shoots growing towards the center of the tree. This allows air to circulate and sunlight to penetrate to the interior.
 If you shorten the shoots (the 25% number), you'll be keeping the fruit more towards the trunk and major branches and reduce the chance of breakage. The remaining spurs will now bear larger and healthier fruit.
For all the trees, it's a good time to remove branches that have broken under the weight of fruit
("really herb, where have you been!....... Some Orchard in Fresno!")  ........Just wait your trees will get there. 
C - "Some more Background:"
  - A good time for pruning over-vigorous trees is after harvest, before dormancy. The other trees are best pruned later,
in the Dormant period. Broken or cracked limbs or branches (some say a Shoot becomes a branch when it's 1 yr old) are a place for disease entry (like any wound). It's best to remove those branches, back to a proper location. The area of a bud (those little swellings, or a leaf node) contains the hormones necessary for proper healing. The smooth sections (internodal area) will not heal, they'll just die back to the bud, and you've not accomplished much.
If the bud (or shoot) is pointing to the direction you want the limb to grow, your cut will also have "training" value. The Branch Bark Collar, at the origin of the branch, has the healing potential to close over the wound (take a look at some old pruned trees). A stump that protrudes will heal poorly, if at all. Pruning paints or sealers are not recommended.    It's far better to place the cut in an area of good natural healing.
Dead shoot ends (black and really dry) may have been invaded by a borer, or bacteria. The dead, wilted and shrivelled leaves may still be hanging down and attached. Prune these shoots off (don't cut through the dead part, go back a ways to where the shoot is normal looking. Diseased branches may have a bacterial or fungal infection. These branches will often have an area of disrupted bark, and oozing a somewhat resinous, brown or black sticky fluid. Cut these branches back at least a foot from the wound, so that you are in healthy looking wood.  (Nice intact bark and cambium layer, with uniform and light cream colored sap and heart wood (not stained brown or black).
When pruning out dead twigs or branches (particularly if they look diseased; oozing, crusting) leave a healthy margin of normal looking branch (up to about 12" if you can) to get well beyond the bad part.
Cut out crossing branches, the areas where they rub are subject to wounding and disease entry. Leave the bigger, or better oriented branch. (Or make an "executive decision" and leave the one that YOU like best. Hey..... you're doing the work!  Michael understands.)
This is also a good time to prune the Citrus trees of any dead branches or twigs, and any branch ends that are dragging on the ground. When you have access to the trunk, renew the "Tanglefoot." If you can keep the ants out of the Tree you're probably 90% to good disease control. Often, nothing more is needed. (Ants kill the Beneficial's larvae that are feeding on the Pests...... that's not good)
Except for the Apricot (remember?), you will probably want to do some Winter Pruning on your trees......
but more about that in the next newsletter.
And remember! with any diseased branch... or going from Tree to Tree..... always sterilize your  pruners between cuts, by dipping  the blades in 70% or 90% Drugstore Alcohol (Isopropyl).     When you're finished, wash off the pruners and spray or  apply  a protective oil. Afterwards  I always resharpen my Pruners, and spray metal parts with an oil protectant like "WD-40." 
Cleaning your Tools between "Cases", is just like washing your hands. BECAUSE..... You're Doing Surgery!  And wear your goggles!!
Hint   For Orchard Instruction, Pruning, Training, or Tree Care: Fill out the Commonvision request online, for a free Workshop at your School Orchard. These are put on by the Master Gardener Orchard Team (not yet available in all Counties).

Disease Prevention

These are, for the most part, general measures designed for the overall health of the Orchard. Occasionally additional measures may be useful for a specific Pest that has gotten out of control. The objective is to have an overall strategy that maintains a healthy ecosystem for plants, critters, and people,and encourages beneficials. It's called IPM (Integrated Pest Management). The point of the Newsletter is to help you keep your trees healthy and vigorous by good cultural methods, so they can resist disease with a minimum of additional intervention. 
A - "Keeping it Simple!"
Make sure the Team has done a good job on the "Clean-up," and check for any "mummies" left on the tree. Remove any residual leaves and hose off the tree using a pressure-spray nozzle. It's beneficial to see that all dead leaves are removed from the tree, and raked up. For the Apple Trees; cut a 3 inch wide strip from a corrugated cardboard box, and wrap it tightly around the trunk (so the little tubes are vertical), just below the first branch (or about a foot and a half above the ground). Remove the band on December 1st, put it in the garbage pail (not for garden composting). 
* If there has been a severe infestation of soft bodied insects or scale a "Horticultural Oil" can be sprayed during the Christmas Vacation period, when children are away, and when the Tree is dormant. 
B - "More in Depth"
OK -  The Corrugated Cardboard band will catch Codling Moth Larvae as they travel down to the ground to pupate. Removal in early December should catch some of the larvae in the little corrugations. Best to burn, or dispose of these with trash. This will help reduce the Codling Moth population in the coming season, although, if you had a heavy infestation we'll have more suggestions for Winter and Spring.
Obviously-diseased shoots and branches can be Pruned out when the tree has gone dormant and you're removing residual leaves. (The tree begins going Dormant when at the ends of the twigs the tiny leaves have been replaced by a tight Leaf Bud. This is where growth will be initiated in the spring               
* Spraying of pesticides (organic or chemical) should only be done if there is evidence of disease uncontrolled by the physical and mechanical techniques. There is always the risk of upsetting the natural balance by injuring the beneficial insects and microbials.  When appropriate however, spray strategies can be used. 

If you're concerned about the level of disease in some trees, call your County Master Gardener office and request a visit from one of the Master Gardeners. The School holiday weekends and holiday weeks during November, December, and January are the best times to use preventive sprays (like Horticultural Oil), and to deal with a School Orchard disease problem.
C - "Why is that ?" 
Many insects and pests (soft bodied insects, scale, etc.) over-winter in the crotch of branches, in the bark, and even  in the bud tips.  Although dormant, they need  to respire (breathe). The Oil will smother them if the coverage has been complete. Horticultural Oil may also be called "Narrow-range" or "Superior" Oil. This technique, is relatively safe and has minimal adverse environmental impact. AdditionallyIt's important to realize that most control measures are only effective at certain stages of a pests life cycle. Oil is most effective during dormancy, at other times the effect may be negligible.
For Deciduous Trees, spraying in the Dormant season has many benefits: The days are cooler and moister, when sprays are less phytotoxic (harmful to plants).  The elements of the tree most likely to suffer damage (leaves, blossoms, new shoots etc.) are safely out of the way. Bees, and other pollinators are relatively safe.

For School Orchards that have Citrus trees, Columbus Day weekend would be a safe time to use Horticultural Oil spray. You don't want to do it any later in the year, and be  sure that the trees are well watered before any spray operation. If they have been a problem; this treatment will help control Scale, Aphid, White Fly and other soft bodied insects that overwinter in the tree.

Fall Clean Up

A - "Keeping it simple!"
When harvests have been completed, remove all fruit from the Deciduous Trees and rake up all; leaves, fallen fruit, and weeds. 
Send all the orchard waste for composting.
B - "More in Depth:" 
Many pests "over-winter" in the fallen fruit and fruit left on the trees. The fruit left on the trees are called "mummies." It's best to have these professionally composed, so that the usually higher temperatures obtained can kill all of the pest larvae, bacteria and fungi. If the tree has been very healthy, without a lot of disease on the leaves, then composting leaves in the garden is fine. If not, put the leaves in with the fruit  for the community composting operation.
Accumulated leaves and weeds are a favored spot for pests to spend the winter, in their own state of dormancy. In the Spring they would be ready for another life cycle..... unless of course they've been composted !!
If you have composted leaves  or other clean mulch, this would be a good time to spread a fresh layer under the tree.
C - "What else can we do?"
OK - While you're under the tree  spreading the mulch (remember to keep it away from the trunk), it's a good time to remove any "suckers"
that appeared since your last tree care. These will be sprouts and shoots that arise from below  the graft union, or coming up directly from the
roots. Don't be fooled by their healthy and vigorous appearance. These just steal nourishment from the tree, we're not interested in
growing more root stock. You can also renew the "Tanglefoot"  (your anti-ant trap!).
On the young trees you can renew the trunk paint (white water based latex paint, mixed with an equal amount of water) right down to the
top-most roots. This will protect against sun burn and  ground-level insect Borers.