Aerial view of hands with knife cutting celery

How to Grow Celery

Celery has been called the ultimate gardeners’ challenge, but if you get a few key things right it is not as hard as it may seem. Celery is a hungry plant that likes it wet and is sensitive to the cold when young. Follow this guide and you should hopefully have your own homegrown celery to put in your Bloody Mary! 

Sowing 

As Celery mustn’t get cold when young, it is great to sow in your S-Series and keep the temperature controlled. Sow seeds thinly in March or April in trays, multi-cell trays or pots. Water the compost thoroughly before sowing and sprinkle just a tiny amount of compost or vermiculite on top. Water again by misting and put a plastic dome or cling film on top. Make sure that it has air holes for ventilation! Keep the soil evenly moist until the seeds germinate because if they dry out they will most likely not germinate at all. Patience is required here as germination can take a long time. 15°C is an ideal temperature but make sure that it does not drop below 10°C at any time as it can make the plant bolt (run to seed) at a later stage in its life. 

Plant care 

After germination, remove the plastic from the top and grow on, ideally at 15°C. When the seedlings are big enough to handle, which might not be until several true leaves appear, pot them on into individual 7.5cm pots filled with peat-free compost. Make sure to keep the plants well watered and that the temperature does not drop below 10°C!

Keep the pot in your mini greenhouse till early summer when the temperatures are above 10°C at all times. To acclimatise the plants to outdoor conditions, lift them outside in a sheltered, lightly shaded spot during the day, and put them back in at night. Do this for about two weeks before leaving them out all the time. Gradually increase the time outside – this is a very important step as Celery can suffer ‘transplant shock’ which makes them bolt at a later stage. 

There are two types of Celery; Trench Celery and Green or Self-blanching Celery. 

For Trench Celery, dig a trench 40-50cm wide and 30 cm deep. Incorporate plenty of well rotted organic matter and plant in a line along the trench. When the plants have reached 30cm tall, earth them up by mounding soil around the stems. Draw 7.5cm of soil at the time so that the stems become blanched.

Green and self-blanching celery should be planted at ground level in blocks 25cm apart to ensure the plants shade each other. This will aid blanching.

If growing celery in pots feed them every 14 days with a balanced liquid general fertiliser during the summer as it is a very hungry plant! It is especially important to keep pots well watered at all times.

Harvesting 

Celery can be harvested by breaking off a stalk from the outside when needed, or cutting the whole plant with a sharp knife at the base once it has reached the desired size. Some trench varieties may last into winter if earthed up well – but most must be harvested before the first frost. 

Watch out! 

Slugs and snails like to munch on young seedlings, so you should protect the plants by keeping them in your Sprout until they’re a bit bigger.

Pro Tip

Mulch around your plants to keep the moisture in.

Nerdy facts

The botanical name of Celery is Apium graveolens.  Wild celery is found on boggy riversides and marshy ground, and it’s easy to see why the cultivated variety needs lots of water!

Recommended Varieties

Here are two great varieties but there are many more to choose from! 

‘Granada’ is a self-blanching variety with pale green stalks. It has a medium to strong flavour.

‘Octavius’ is a trench celery with medium-length, slightly ribbed stems.