Why Are My Celery Stalks So Thin?

Question: Something is going on with my celery plants. Why are my celery stalks so thin? I’m starting to think I’m not watering them enough. -Laura T.

Answer: There are several reasons that your celery may be producing spindly stalks, and we’ve explained each of them below along with their symptoms to help you determine what’s affecting your plants. Once you’ve figured out the problem behind your skinny celery, you can take the steps we describe to correct the issue.

• Celery variety: The type of celery plant you’re growing might have something to do with the size of its stalks. Look for varieties referred to as “stalk celery,” which is the type cultivated for produce departments because it’s known for having thick stalks. Varieties in the “cutting celery” category will produce a larger number of stalks, but each stalk will be narrower, and cutting celery also creates more leaves than stalk celery. The similarly named plant celeriac is a root vegetable with very thin stalks that resemble celery, but the celeriac plant is not the same thing as celery grown for its stalks.

• Improper harvesting: If you harvest your celery stalks too early, they’re bound to be thin due to their immaturity. Although celery’s maturation period is relatively long, allow the plants to finish growing for the entire 130 to 140 days recommended. If frosty weather comes through your area before the celery has matured, you may need to harvest before the maturation period is over, in which case you can expect thinner than usual stalks as a result of the early harvest.

• Lack of fertilizer: Celery is a relatively heavy feeder, but its roots are small (just two or three inches deep and six to eight inches across). The plants also just aren’t that efficient at collecting nutrients. That’s why celery plants depend on fertilizer for the nutrition they need. Prepare the soil where celery will grow with a 4-4-8 fertilizer or another blend that’s high in potassium, and mix the fertilizer into the top six inches of soil. You can also apply one inch of well rotted compost per 100 square feet of celery bed before planting. Side dress with a quarter cup of 21-0-0 nitrogen for each 10-foot row of celery plants at four weeks and eight weeks after transplanting into the garden.

• Not enough water: Celery is a low-calorie food because it’s mainly made up of water—so celery plants that produce spindly stalks may be doing so because they’re short on hydration. Make sure your celery is getting the recommended one or two inches of water per week during its growth period, between rainfall and the moisture you give the plants.

• Overheating: Although celery needs six hours of sun each day, it’s best for the plants to get their dose of sunshine early in the day so they can be protected from the heat of the afternoon. If the plants get too hot due to the beating afternoon sun, their growth can be affected, resulting in thin stalks.