Again this year, the excellent weather that makes gardening so much fun even through winter has the potential to become a problem. Winters are innately mild here, and like this year, are sometimes mild and warm enough to prompt many plants to bloom much too early. Many of the fruit trees and their ‘flowering’ (non-fruiting) counterparts are already finishing bloom as if it is the middle of spring, even though the equinox is about two weeks away. This should not be a problem for the flowering cherries, plums, pears and apples (flowering crabapples), but is risky for the many trees that should produce fruit.
The problem is that, despite the weather, it really is winter and early spring, so could potentially rain while fruit trees are blooming. The rain can batter the blooms, or cause them to rot before they set fruit, compromising or even eliminating the fruit production for the following summer. Trees that are not blooming, or just barely showing ‘color’ of the first few blossoms, should be safe. Also, the trees that bloomed earliest and have already set fruit should likewise be safe, as long as the weather does not stay rainy too long, which it almost never does here. Trees that are in full bloom when it rains are the most sensitive to damage.
It is impractical to cover mature trees with plastic sheeting to protect them from rain. Even if it is possible to get the sheeting over the trees, it knocks much of the bloom or developing fruit off anyway. Also, if the sheeting is not removed when the rain stops, it can trap humidity, which can rot the blooms that were so carefully protected from the rain. (Although, high trees hold the plastic high enough from the ground to allow for good air circulation.)
Small trees are easier to cover, but do not produce enough fruit to worry about. In other words, it would be easier to buy fruit at a market, or to get it from friends and neighbors with different varieties (that bloom at different times) than to put too much effort into protecting trees from the rain. In most situations, it is best to just accept that fruit trees will sometimes have ‘off’ years when they either do not produce, or produce only minimal quantities of fruit. The good news is that trees that lose some but not all of their fruit often produce best.