Best Time to Fertilize Citrus and What Specialized Citrus Fertilizers Are Available

Citrus is a fairly well-known fruit in China, currently widely available on the market in our country, generally coming into season in winter. Many people like to grow citrus now, but during the growing process, if you want it to grow well, fertilizing is a very key step. When fertilizing, both the timing and the choice of fertilizer involve some techniques.

Best Time to Fertilize Citrus

There are many stages for fertilizing; you cannot really call any one of them the best, because all of them are important for fruiting, increasing yield and improving quality, from the base fertilizer in winter at the start of spring, to the shoot-promoting fertilizer in early spring, to the fruit-setting and fruit-stabilizing fertilizer, and then to the fruit-sizing and shoot-promoting fertilizer. All of them are important and all have their timing, and adjustments should be made according to the seasonal temperature changes each year, according to the vigor of the tree, and according to the types of fertilizer used over the years.

What Specialized Citrus Fertilizers Are Available

For specialized citrus fertilizer, a full-element compound fertilizer is a relatively good choice, as its nutrient elements are more abundant and the plant grows better and more vigorously. For top dressing, a phosphorus-potassium fertilizer is a relatively good choice, as it can promote more flowering and fruiting in the plant.

Fertilization Methods for Citrus

1. Methods such as ring trench application and strip trench application can be used. Farmyard manure used must be fully fermented and decomposed; chemical fertilizer should not be applied in excess at one time, and should be applied lightly and frequently. In addition, the main root layer of mature trees is distributed at a soil depth of 40-60cm, and their main absorbing roots are the fibrous root tips——the new root portion, so this should be taken as the basis when deciding the depth and location of fertilization.

2. Carry this out in November-December. The specific method is to apply once every other year, alternating between trees, digging radial, semi-ring, or ring-shaped fertilization trenches outward from the drip line of the canopy, taking care not to cut off large roots while digging. The amount of fertilizer applied should be increased or decreased according to tree age and vigor. Combined with root pruning, place weeds and green manure at the bottom layer of the trench for each tree before applying the base fertilizer, and mix thoroughly with part of the soil in the fertilization trench. Bearing trees should be given additional potassium fertilizers such as plant ash and potassium sulfate to facilitate flowering and fruiting.

3. Fertilization quantity. For the annual fertilization amount, apply 0.6kg-0.8kg of pure nitrogen per 100kg of fruit produced, and the ratio of nitrogen, phosphorus and potassium is preferably 1:0.4:1. Calculated at a yield of 2000 kg per mu, 12 kg of pure nitrogen, 5 kg of phosphorus and 12 kg of potassium should be applied per mu.

Top Dressing Techniques for Citrus

Mainly quick-acting chemical fertilizers, and where conditions permit, they can be applied together with decomposed farm animal manure water or oil cake water.

1. In the young stage, mainly nitrogen fertilizer (urea), plus an appropriate amount of high-quality compound fertilizer, applying about 0.1 kg per tree each time. Specifically, according to the tree's initial shoot-sprouting stage and rapid elongation stage (middle stage), dig holes or trenches at the drip line of the canopy and apply, and cover well with soil after each application. During fertilization and for 7 days afterward, the soil must be kept moist; apply less to trees with strong vigor and more to those with weak growth.

2. For top dressing of bearing trees, specifically apply spring bud fertilizer 10-15 days before sprouting from late January to early February, mainly nitrogen fertilizer (0.2 kg per tree), together with phosphorus and potassium fertilizers (0.1 kg each per tree), to promote spring shoot sprouting and flower bud differentiation. Apply a fruit-stabilizing foliar fertilizer once 5-7 days after flower drop in late April to early May, mainly nitrogen and phosphorus fertilizers (1 kg of monopotassium phosphate per mu sprayed at a 0.2% concentration), to increase the fruit-setting rate. Apply fruit-sizing fertilizer after the second physiological fruit drop stops in late June to early July, mainly nitrogen and potassium, applying about 1 kg each of high-quality compound fertilizer and raw oil cake per tree, to improve fruit quality.

There are many times to fertilize citrus; fertilization is needed at the start of spring, during fruiting, and so on. There are also many fertilizer choices, so you can ask around more on the market. Citrus fertilization methods include ring trench application, strip trench fertilization and so on, and you can choose according to your own actual situation.