Fig. 1 Flower buds and new leaves emerge as the temperature rises.
As the California temperature rises, the once cold-beaten citrus trees are now on a rebound. New buds are starting to surface from under last-year's foliage - promising another bountiful crop (Fig. 1). In order to have that promise materialize, there are a few things to keep in mind.
Factors to Consider All Year
Sunlight. Citrus plants need long hours of sunlight. Make sure they get at least six hours of good sunshine everyday.
Soil Nutrient. Citrus are heavy feeders. Apply fertilizer during the early spring. In my garden, I use 16-16-16 in late winter to replenish what was spent during fruiting and to give them an early starter food for spring. Repeat fertilization once a month and give them a dose of fertilizer containing micro-nutrients - especially for plants grown in containers.
Soil Moisture. Contrary to popular belief, citrus plants require moderate amounts of water. Water them regularly in the early spring to ensure excellent fruiting. Fruit-set is highly dependent on optimum water during flowering to fruit set.
Fig. 2 Allow the trees some rest by harvesting the last season's fruits.
Things to Look Out for in Spring
Last season's fruits. Citrus fruits are beautiful and unlike other fruit trees their fruits do not abscise readily. If you have not done it already, it is time to harvest the remaining fruits to allow the plants to completely focus their resources into the development of the new crop (Fig. 2).
Suckers/Water Sprouts. Water sprouts also known as suckers are a natural occurrence in citrus plants. They are vigorous young branches growing vertically which often come with thorns (Fig. 3). They are healthy-looking but if allowed to remain, they will exhaust huge quantities of resources such as water and nutrients at the expense of the rest of the plant. Therefore, cut off water sprouts as soon as possible.
Fig. 3 Water sprouts are vigorous growth with
Fruit Drop. Flowering and fruit set directly affects final yield of citrus plants.Under favorable conditions, citrus plants generally set more fruits than they can support and at some point, the tree will naturally shed some of the tiny fruits (usually the size of jelly beans). Excessive fruit drop could be a result of water stress. Numerous studies have shown that water stress influences flowering and fruit set. Make sure the trees get sufficient soil moisture during these critical stages.
Pests. Snails, slugs, scales, and leafminer can all pose a challenge to citrus plants. There are a million options when it comes to pest management. Nonetheless, success can only be achieved by proper timing. Control snails and slugs in late winter before they can have a chance to lay eggs or damage plants. Applying horticultural oils can prevent scale infestation. Spinosad or Pyrethrin can control the leafminer moth before oviposition. Still, allowing nature to deal with its own seasonal imbalances is even better. When pests arise, some insects that are antagonistic to them also flourish.
With a little attention to details, your citrus trees will reward you with a bountiful crop.