Once the temperatures outside are consistently above 50 F, you can plant your celery into your garden. Remember that celery is very temperature sensitive, so don’t plant it out too early or you will kill or weaken the celery plant. A growing celery plant needs a lot of water. Make sure to keep the soil evenly moist and don’t forget to water them. Celery can’t tolerate drought of any kind. If the ground isn’t kept consistently moist, it will negatively affect the taste of the celery. You’ll also need to fertilize regularly to keep up with the nutrient needs of the celery plant.