The reason celery is considered something of a challenge is because it needs approximately 4.5 months to grow in cool weather. It also requires specific amounts of fertilizer and water. If your soil is moist and there is a lot of organic matter in it, this will be advantageous. If your celery doesn't have access to water even for a short period of time, it could cause problems, explains Garden.org.
Celery roots are limited and can only stretch 2 to 3 inches in depth and 6 to 8 inches away from the plant. This means the top part of the soil must contain all the nutrients that the celery needs in addition to having adequate moisture content.
If you live somewhere that is hot all of the time, your celery plants aren't going to survive. They do best in areas where the winters are mild and the summers are reasonably cool. They also do well in areas where there is a cool, long growing period in the autumn.
It takes celery seeds a good while to germinate. If you soak the seeds overnight, this jump starts the germination process. You will need to start your seeds in flats indoors or in plant boxes about 10 or 12 weeks before the last frost. Transplant the plants to peat pots when they are 2 inches in height. If you are planting them in flats, locate the plants 2 inches apart.
You can put the celery in your garden a week or two before the last frost date, but the plants need to be at least 4 to 6 inches high before you set them outside. If the temperature drops consistently below 55 degrees Fahrenheit for two weeks straight, this may cause the plants to prematurely go to seed. However, it is still worth the risk to put them out early since such a long growing season is required.
When you set the celery outside, trim off the outside leaves because this will help them get over the shock of being transplanted and growth will start sooner. Put the plants 8 inches apart. Mulch them when they're 6 inches tall. This keeps the roots cool and soil moist and prevents the growth of weeds, which can interfere with the growth of the celery. The celery requires water. If it doesn't get enough, it will become pithy or hollow and become stringy and tough and won't be good to eat.