Apple Trees

The following information is from our gardener, Mark Palczewski.

Pruning -

At minimum, we should prune the trees to remove dead and damaged branches as well as open up the tree to improve air circulation.
The sooner the better. Some articles have stated that pruning can be done anytime of the year, while others recommend pruning when the trees are dormant. The trees are currently at the green tip stage in bud development, but with the weather pushing 80 degrees, they may soon be at the half green or tight cluster stage.

Apple Scab -

The organic fungicides are:
- Lime-Sulfur
  - Low toxicity, but very caustic to the skin, lungs, and especially the eyes - can cause permanent eye damage.
  - Most effective.
  - Can cause russeting of fruit and leaf burn.
  - Can’t be sprayed above 80 degrees or within 1 month of an oil spray.
  - Low toxicity for bees.
- Bordeaux Mixture(Copper Sulfate)
  - Toxic and caustic.
  - Effective
  - Can cause leaf burn.
  - High toxicity for bees.
- Neem Oil
  - Safe
  - Less effective than Lime-Sulfur
  - Has insecticidal properties - can kill harmful as well as beneficial insects
  - Toxic to bees directly contacted, low toxicity otherwise.
- Bacillus subtilis
  - Safe - Bacillus subtillis bacteria is commonly found everywhere.
  - Efficacy is questionable.
  - Safe for bees.
- Potassium Bicarbonate
  - Very safe(Baking powder)
  - Less effective than Lime-Sulfur
  - Safe for bees.
- Copper Solution
  - Toxic.
  - Highly toxic to fish.
  - Effective
  - Can build up up in soil and cause soil toxicity
  - Low toxicity for bees
Keeping the are around the trees clean can help in the reduction and severity of the infection.This includes:
- Cleaning up leaves, branches and fruit that has fallen from the trees.
For apple scab, I would recommend using either Potassium Bicarbonate or Bacillis subtilis. They are organic and very safe for humans and bees.
A spraying program should begin as soon as possible, since the leaves are susceptible once the buds break.