Buds are formed on trees during the growing season. When winter comes the buds remain on (deciduous) trees when the leaves drop. They also remain on trees that hold their foliage (evergreens) over the winter. In the spring these buds begin to swell as the leaves or needles grow. As they grow the bud scales are simply pushed out and fall off.
Some trees will break bud and form leaves. Some will push out flowers and seeds before buds break. Some will form leaves and flower several weeks or months later. And others will leaf out and flower almost simultaneously.
When protecting plants from fungal diseases like Powdery Mildew or Bacterial diseases like Fire Blight it is important to time the treatments properly. Below is a visual guide to help you understand when to call us for treatment.
This Apple bud has just begun to break through the bud scales. It has not pushed out enough leaf tissue yet to warrant spraying for fungal control or fire blight.
At this stage a first application of fungicide will help control infections from occurring. This is not an appropriate time for fire blight flower treatments. However, a trunk injection for fire blight control can be done at this stage.
This is still a good time for a first application of fungicide or it may be 7-10 days after the first application and be time for a second. The flowers have begun to emerge but are not ready for treatments to control fire blight or fruit suppression.
This is the stage at which the application for Fire Blight or Fruit Suppression should begin. Because flowers do not open all at once on the same tree it is necessary to do at least two applications to cover all the flowers as they open. As you can imagine it is difficult to cover all the flowers so it is imperative that you let us know when your flowers start opening.