Celery & Celeraic

Celery and celeriac are biennial and will cross-pollinate with each other. They will also cross-pollinate with wild celery though this is not a common plant and found mostly along coastal areas. It is easier to grow just one variety every year for seed. You can grow other varieties just for eating, as long as you remove any plants that are looking to go to flower.

Grow the plants in the first year as you would for eating. Keep as many of the most true to type plants as possible by removing those plants that may not look so vigorous or has a tendency to bolt. Also, any plants that may have discolouration in the stems or leaves and look different from the others. You should aim for at least 16 true to type plants to maintain a good genetic diversity.

Apart from leaf celery, which is hardy and can be overwintered in the ground. The other types of celery along with celeriac will not withstand the frosts and will have to be protected by applying a mulch around the plants. Alternatively, they can be lifted in the autumn with the leaves trimmed, and stored like other root vegetables in boxes of moist sand or a similar organic moist material as the roots like to be kept damp but their stems dry.

In the spring, replant the stored plants. By the beginning of summer branched flower spikes with umbels of small white flowers are formed. The plants can reach a height of over 1m and will need staking. Pollination from one plant to the next is carried by insects. You will need to isolate your plants with a fleeced cage if there are other flowering celery and celeriac varieties close by. The plants that need to be caged can be pollinated through the use of blowflies.

Harvesting can begin when the plants start to turn yellow and the seeds on the umbels turn a grey-brown colour. It is advisable to harvest the seed as soon as each umbel becomes ripe as celery is known for shedding its seed easily. Celery and celeriac seed are very small and thus can be difficult to separate from the chaff. Using sieves is an effective method of cleaning the seed. More information on seed cleaning can be found under our section ‘Seed Cleaning and Drying’ on our website.