Monday, April 18, 2011

Dormant Spray

We spray our fruit trees and rose bushes in the spring with dormant oil spray.  The timing is tricky because you need to spray before the buds open so as to not damage the new leaves.  You do not want to spray when the blooms are out (some fruit trees bloom before they leaf out) because you can harm the bees.  On the other hand, you do not want to spray if the temperature is below 65F.  You also need a calm day with little or no wind.  And last but not least, you want the weather clear for at least 8 hours after you spray so the rain doesn't wash the spray off the trees. 
We use a combination of lime sulfur and horticulture oil that is considered organic.  Lime sulfur is a fungicide and also kills mites and insect eggs that have over-wintered on the tree or rose bush.  We follow the mixing proportions on the bottle. 

We sometimes use store-bought horticultural oil as well.  The oil smothers the eggs of insects such as aphids and leaf-rollers.  It also kills scale insects and mites.

Most of the time, however, we mix our own oil.  We use 1 Tbsp of cooking oil

And 1 tsp of dish detergent in a gallon of water.  We mix up the lime sulfur, oil, soap and water in correct proportions and pour into the sprayer.  You start at the top of the tree and spray all the bark on the branches and trunk.

The first year we used this sprayer but it was too small for the number of trees we have.  We wore ourselves out pumping.  You have to push the handle on top, up and down to build up pressure.  Plus it didn't hold very much so you wasted alot of time mixing.

Last year we used this sprayer.  It is carried on your back and has a longer handle so it is easier to pump up the pressure.  It holds more volume as well so you don't have to fill it as often.  The down side is the weight on your back while climbing up and down the ladder.

This year we got this sprayer.  It runs off a battery so no pumping.  Usually you would put it on your quad and drive around and spray.  We don't have a quad and it would be impossible to get to all the trees with a quad anyways.  The guys rigged up a board on the wheelbarrow for this year and it worked fine enough.  We are going to try to find a wagon that will hold the tank and we can pull it around the yard.  The pressure on this tank was great so very little ladder climbing was necessary.

1 comment:

  1. Thanks for the informative post, Joan! I've never sprayed my trees with anything before and thought I'd give the dormant oil a try this year. I never got a day that wasn't either rainy or terribly windy, so mine didn't get done again this year. :P