Growing Celery

How to buy celery

Celery (Apium graveolens) is a versatile vegetable, because it is delicious and health-giving both raw and cooked. Its crunchy texture and nutty flavour compliment salads and dips, and it imparts a crisp freshness to casseroles and soup.

Celery is an annual which can be purchased either as seed which takes between two to three weeks to germinate, or seedlings which mature after approximately five to six months after planting, depending on the climate and position. Many stringless varieties are available.

Where to plant celery

Celery is a juicy vegetable which demands plenty of fertiliser and moisture to develop well. Ensure that your soil is deep, rich and moist enough to support the plants during their relatively long development time. Heavy soils should be dug over well to a depth of 25cm and if they are very clayey, gypsum should be added at the recommended rate to break up the clods. The addition of a generous quantity of animal manure (such as 5 in 1 Organic Fertiliser) will help retain the moisture as well as provide essential fertiliser to the young plants. Similarly, sandy soils should be laced with compost and manure to bulk up their porous structure.   

Despite being a moisture lover, celery insists on good drainage but being shallow-rooted it should never be allowed to dry out. As it is a cold season crop, plant it in a site where it will receive plenty of winter sun.

How to plant celery

Seeds can be sown directly into the soil in which they are to grow but better results are gained if they are sown into individual cell-pack punnets and transplanted when they are approximately 10cm high. This may take up to ten weeks as they are slow developers. The average family will require about 15 plants to see them through the season, and unlike some vegetable varieties which can be planted a few weeks apart to stagger production, celery should be planted in one go.

Seed should be sown in punnets to a depth of 6mm and lightly dusted with seed raising mix or sand and vermiculite. Keep moist until the seeds have germinated.

If you are sowing seed directly into the ground, excavate a shallow drill and allow approximately 30cm between each plant. Cover the row of seeds – either by gently replacing the soil from either side of the drill or using a sand/vermiculite mix – and water well.

How to grow celery

Ensure the soil around the plants is free of weeds which will compete with the celery for food and water. To grow well, celery requires plenty of food, and a fortnightly application of a soluble fertiliser such as Searles Flourish® Vegetable & Tomato is essential if they are to continue producing healthy new growth.

The maturing stalks of all types except the self-blanching varieties will naturally become dark green through the process of photosynthesis and if they are allowed to do so, they will become tough and bitter. To prevent this from happening, blanch your plants by wrapping their stems in newspaper or cardboard, or cut the bottom out of a waxed milk carton and gently slip it over the plant. For extra protection, mound the soil gently up around the individual plants until they are ready for harvesting. After approximately three months of growth, the outer stems can be picked as required, and the paper sleeve replaced until more stems are needed. Once the plants have reached their full maturity they should be harvested within six weeks, as plants left in the ground become woody and inedible, even when cooked.

Pests and diseases of celery

Celery requires plenty of moisture and because of this, humidity can build up around the plants, providing a perfect breeding ground for a fungal disease called septoria leaf spot. If this becomes a problem in your garden, use a seaweed-based soluble fertiliser such as SeaMax Organic Fertiliser Liquid, applied to the foliage and the soil, on a fortnightly basis.

Bonus point: Celery was used medicinally by the ancient Greeks. Celery juice is reputed to act as a diuretic and helps ease fluid retention, while an infusion of celery leaves may aid rheumatism. Celery should not be consumed excessively.