UNITED STATES—Climate is what makes gardening so excellent here. It is just warm enough in summer for plants that like a bit of heat, but not too unbearably hot for too long. It is just cool enough in winter for plants that like a chill, but not cold enough for hard frost or heavy snow. The climate is also comfortable for us while out in the garden! Yet, even local climate is neither perfect nor predictable.
El Nino is still out there, and likely to deliver an abundance of rain. The rain last month was great while it lasted. This presently dry and warm weather in between has been excellent, but is likely to cause serious consequences. Some deciduous plants that are normally bare through winter are being deprived of adequate dormancy. Some are blooming prematurely, and may foliate soon.
When the rain resumes, it will ruin some of the premature bloom. This is generally harmless for most fruitless flowering trees like the various acacias, flowering plums and saucer magnolias, but compromises their most alluring feature. It can be more dangerous to flowering pears (including evergreen pear) and flowering crabapples, because wet blossoms can be infected with fire blight.
The more serious problem is that rain ruins blossoms and juvenile fruit of various deciduous fruit trees. Stone fruits such as almonds, apricots, cherries, plums, prunes, peaches and nectarines bloom first, and do so with delicate blossoms. If the blossoms do not get knocked off by rain, the juvenile fruit will rot if it stays damp too long. Many fruit trees are likely to lose all fruit this year.
Apple and pear trees should be safer because they bloom later, and bloom with more substantial flowers. (However, like their fruitless relatives, their wet blossoms are very susceptible to fire blight.) Persimmons and pomegranates bloom even later, and with even tougher flowers, so should be safe. Figs are in a league of their own, and should be fine if summer is warm.
Fortunately, destruction of bloom and fruit, although disappointing to us, is harmless to the affected trees.
Avocado trees, Persea americana, grown from seed need to be about five years old to produce fruit that can be considerably different from the fruit from which the seed was taken, although such fruit is almost always quite good. Some trees need to be twice as old to produce. Grafted trees from nurseries are specific varieties that can start to produce their specific fruit immediately.
Fruit production is notoriously variable. Some healthy trees may be unproductive for a few years, and then suddenly produce more fruit than the limbs can support. Trees that are very reliable and productive may sometimes be unproductive or significantly less productive for a season. It is nearly impossible to determine which environmental factors inhibited bloom and fruit development.
Mature trees can be more than 40 feet tall, with awkward branch structure. The lush dark green leaves are about four to eight inches long. The tiny yellowish green flowers barely get noticed until they deteriorate and fall to the ground like corn meal. The dark green and pear shaped fruit is quite heavy. It develops on the tree, but then ripens after it falls or gets picked and brought inside.