1, requires a lot of nitrogen fertilizer. Celery needs a lot of nitrogen fertilizer during the whole growth period, mainly ammonium bicarbonate topdressing. Do it a few times, and generally need topdressing 2-3 times. If the soil lacks boron, 0.5-0.75 kg borax should be applied per mu to prevent the petiole from breaking and affecting its practical value. Spraying 0.2%-0.4% calcium chloride solution can prevent the occurrence of black heart disease.

2, it is not appropriate to topdressing urea because after topdressing urea, celery grows slowly, cellulose increases, plants are prone to aging, quality is reduced, and it tastes bitter.

3. topdressing organic fertilizer When celery is managed in the field, topdressing fully decomposed organic fertilizer after retting, because applying organic fertilizer can improve the quality of celery. However, if there is no decomposed farm organic fertilizer, it should not be used as topdressing, so as to avoid burning and rotting roots. After applying organic fertilizer, celery plants grow tender and strong, fiber is reduced, quality and yield are greatly improved.