Some people refer to it as a dormant spray, others (myself included) call it a cleanup spray; still others call it a preventive spray. They all are talking about the “kick off” spray to start your spring garden. One expression actually means something totally different from the other two.
A strictly DORMANT spray must be given while plant life is entirely dormant. This practice originated in the days of our forefathers when no material was available which would be safe to use on plant life after it began to function. One spraying was done with straight lime and sulfur in the hope it would possibly do good.
Actually it was impossible to spray totally dormant plants successfully because insect life is subordinate to plant life and unless sap has started to flow insect life has not yet “come alive,” nor do fungus spores become active so early in the season. Another insecticide in those days was arsenate of lead.
Preventative Spray
When we speak of a cleanup spray we, also, mean a “preventive” spray. It is so much easier to prevent trouble than to battle it when it is strong and powerful. This spraying should be given to plants (especially roses) just after they start to function, that is just as soon as the sap begins to flow, it is also the proper time to prune roses.
Immediately after pruning is finished, give the roses their cleanup spray. The best material use to be lime sulfur and oil emulsion. People would mix lime sulfur spray with a light oil emulsion to achieve this two-purpose fungicide-insecticide.
Others preferred a product called CALSUL which combined the lime sulfur (calcium polysulphide) with vegetable, mineral and organic oils so it is a perfectly balanced chemical formulation complete in one bottle. You added only the required amount of water to make a perfect spray.
By this time insect life has begun its activity but it is young, tender and easy to kill. Fungus has not yet had time to get out of control. Such a spray used at this time checks both evils and your roses get off to a clean start. If this is done after pruning you have accomplished one of the most constructive things possible for your rose garden all through the year.
Spray Plant and Soil Area
Spraying the soil area around the plant material is just as important as spraying the bushes as insect life hibernates and fungus spores overwinter on the soil surface.
A well rounded cleanup spray will check spider mites, scale and thrips, it destroys many of the overwintering aphid eggs. There is no chance of entirely preventing aphid infestation, the eggs hatching in early spring are female, the stem mothers. They fly from one place to another, starting colonies wherever they settle.
It is a matter of course that some of these colonies will get into your garden. Of course, when they do appear and become numerous you will have to spray. I’m not a believer in over-spraying, one good spraying for aphids thoroughly applied with a proper material will carry your garden along for a couple of weeks.
There will be re-infestation of some aphids even the very next day after spraying. As these become numerous it is a good idea to rinse them off the plants with your water hose. This does not kill the pest but it gives the plants a rest before being re-infested. And after a couple of weeks spray thoroughly again.
The Advance of Warm Weather
As the warm weather advances the aphid becomes less hardy. Nature gives you a hand by means of natural mortality and your plants go on into the season quite happy.
If your cleanup or preventive spray in the early part of the season is made with an oil emulsion it will also break down the eggs of the red spider. Earlier we never heard about red spider on roses but now they are one of the major rose pests.
This situation is undoubtedly one of the common tragedies resulting from the use of many new insecticides that have destroyed the beneficial predators. Your cleanup spray will rid the bushes of red spider but you may have to use spray on them later in the season.
Spores of black spot, mildew, rust and other fungus diseases are prone to overwinter, invisible in the body of the rose bush as well as in the soil and, of course, there is nothing finer than the lime sulfur content in your spray material to destroy them.
The Plus of Early Spring Spray Applications
You can see the advantage of spray material in the early spring. In addition to destroying many fungus spores, another advantage is not only to kill insect life but to prevent them from spreading any fungus spores that may be prevalent such as black spot and mildew.
Our grandfathers had the right idea when instituting the dormant spray but modern improvement in spray materials has been a boon to roses and other plants through the medium of a preventive or clean-up spray which can be given right after pruning.
