Celery: not the easiest vegetable to grow. Photo: http://www.wearefound.com
Question: I have a problem with my celery. It looks fine, but the stalks are hollow. Why?
Answer: This is a common problem with celery (Apium graveolens dulce), not the easiest vegetable to grow under most conditions.
It may help to understand that wild celery is a plant of marshes and stream edges, used to a rich, organic, very humid soil. As a cultivated plant, celery’s short roots aren’t very efficient at reaching minerals or moisture, so it prefers a soil that is always moist, light and very rich in minerals. And as you can imagine, celery loves compost, so add more annually!
Heat and drought are its two worst enemies, leaving it with hollow stalks and a stringy texture. Drought-stressed celery may even start to go to seed, leading to a bitter taste.
Also, mechanical damage can make the situation worse. If possible, avoid hoeing at the base of celery plants. That injures the roots and can lead to further drought stress.
Mulch to the Rescue
Even home gardeners who don’t normally mulch their crops should make an exception for celery. Mulch it heavily with an organic mulch about 3 to 4 inches (7 to 10 cm) thick. That will help keep the soil cool and moist. Mulching also keeps down weed germination (therefore, you won’t need to hoe!) and helps make sure that grains of sand don’t work their way into the heart of the plant, often an annoyance with store-bought celery.
And, of course, water early and often. As soon as the soil feels the slightest bit dry to touch, you should be out watering your celery.