Plants
   Vines
   Trees
   Shrubs
   Herbaceous perennials  

 Information
   Planting instructions
   Planting instr. (acid)
   Printable plant list
   Newsletter archive
   Ask the Chuckster

 Driving directions

 Chuck’s courses
 and consulting

 Driving directions

Ask the Chuckster...
Maintaining plants under insect and disease pressure

I'm concerned about fire blight. What should I do?

There’s much disease pressure on useful plants as the heat and moisture build this time of year. As usual, the early the better for treatment, ideally around the time the plant is leafing out and beginning to flower.

Early signs of fire blight, most likely on apples or pears, are seen when the tips of the plant begin to curl like a shepherds crook and turn black.

The first order of business is to prune to 6” below any sign of infestation.

Next, treat with neem oil or horticultural spray at about weekly intervals until no more signs appear.

If the fire blight is advanced a more powerful biological bactericide is in order. At the nursery we use Streptomycin sulfate which is OMRI certified and non toxic to people or the environment.  Another option is a sulpher-based fungicide such as copper sulfate or lime sulpher.

What about that moldy blotchy stuff on the leaves?

Another common disease this time of year is a foliar disease called downy mildew which looks like little white powdery blotches on the upper side of the leaves.

In our nursery this is the most common on our serviceberries.

Over the years we’ve tried many things but have settled on a combination of Organicide, which is a sesame oil based product and Serenade, an organic fungicide. The oil coats the leaves and provides some protection while the fungicide works on the fungus.

In general, as long as there are high humidity conditions we will continue to see plant diseases. If they are too far advanced treatment won’t undo the damage that’s been done but further damage can be stopped.

Inadequate air circulation puts plants at the greatest risk. Hillsides are ideal for orchards and be sure to prune so that more air and light can circulate through the center of the plant.

Some Insect Advice

This time of year the aphids are out in full force. They tend to inhabit the young tender growth on plants, and while rarely fatal, can distort or deform the new leaves.

The first line of defense is a healthy ladybug population. Ladybugs can easily be ordered online from a beneficial insect company. Neem oil is also an option as is Spinosad, an organic spray that addresses soft-bodied insects like aphids.

Slugs are another trying insect, particularly for strawberry growers. For a permaculture solution, incorporate chickens and ducks into the strawberry patch, as they’ll happily clean up the slugs. Short of that, you can use Slug-O which is iron phosphate. While it gets rid of the slugs it also adds nutrients to the plants themselves.

From the UPN June 2010 newsletter.