Fruit Trees – Dormant Oil Sprays

I can ignore a few holes in my lettuce leaves or the occasional blemish from a hungry bug, but I can’t STAND aphids.  It seems like they pick a fruit tree to colonize each year, with their ants helping them along.  Sometimes a thorough spraying with the hose will help, but last year we battled aphids on our LaCresent plum all summer.  The trunk was wrapped with sticky Tanglefoot, aphids were shot of via hose on a regular schedule.  The quickly growing leaves curled and hid entire generations of damn aphids inside.  At the tail end of the summer, aphids populated the Honeygold apple.  They must have overwintered on a few of the leaves, and I’m seeing tiny aphids before the tree has even started to leaf out.

Fortunately, I bought a backpack sprayer over the winter and I’m excited to use it!  Michael Phillips, an organic orchardist, suggests the following recipe for a 4 gallon backpack sprayer:

2.5 ounces of pure neem oil
1 generous teaspoonful of soap (emulsifier)
10 ounces of liquid fish emulsion
6 ounces of mother culture of effective microbes (I use aerated worm compost tea)
1/2 cup of blackstrap molasses dissolved in warm water
5 tablespoons of liquid kelp or half an ounce (dry weight) of the seaweed extract

Top off with water.  Spray your trees to the point of runoff on a dry, sunny day.  Kill those aphids.

If there was a toxic compound that killed all aphids, I would have a spray bottle full.  There is nothing more irritating than trying to fight an aphid infestation on your poor little artichokes or dill.  However, nothing wipes them out, so a smothering spray like this concoction is a good option AND delivers some nutrients to your plants at the same time.

Why is it called a dormant oil spray?  It is usually applied early in the spring, when trees are still dormant.  At this stage you can easily reach all the crevices where bad bugs overwinter.  Once a tree leafs out it is really hard to reach every surface, and if you miss one aphid stronghold they’ll repopulate!