This post covers:
- How to germinate the seed
- Transplanting/optimal soil conditions
- "Cut and come again" - celery beyond the first cutting
- Nutritional content of celery and why to only eat it organically grown
How to germinate the seed: Most gardeners have a favorite way of germinating seeds but we'll just share what works for us and you can adapt it to your own preferences.
Celery seed is very slow to germinate. Seeds can take 2-3 weeks to show their first leaves and the plants are not big enough to be planted in the ground for at least two months after that. Here in the Pacific NW, USA (USDA zone 7b) we start our celery in mid-February and they're usually ready to go into the ground by late April or early May. Don't worry if you've missed that planting schedule; celery can be started all through the spring.
|Celery seed is very slow to germinate. Celery seedlings (left) over 1 month old. Lettuce (right) approx. 3 weeks old.|
|One celery plant starting to flower. One celery plant will yield thousands of seeds!|
|Being vegetarian, we eat a lot of tofu! With holes drilled in the bottom for drainage, they make excellent pots for germinating seeds. |
A good rule of thumb is to only cover seeds with soil twice as deep as the seed is thick. So, a millimeter-sized seed, would be planted approximately 2 mm's deep.
They will germinate best with some bottom-heat from a heat mat,
or to be kept indoors until the seedlings pop up above ground but as
soon as the green leaves appear they need sunlight or a grow-lamp. Keep the soil moist (but don't over water!) by bottom-watering (in a shallow dish) or with a plant-mister as too much water can kill the tiny seedlings.
The seedlings will develop an extensive root-system first which can take many weeks. Don't give up on them!
Transplanting/optimal soil conditions: Our celery seedlings go through two transplanting processes. First, once the root-system has developed and the plants are about 1/4 - 3/8" tall, we carefully tease them apart and give them each their own pot. Jumbo six-packs work fine. We have also used the tofu containers mentioned above (six to a container). These work well if you'll be able to do the next phase of transplanting as soon as the roots fill the soil. The jumbo six-packs extend this time a little bit as they hold more soil.
|Transplanting tiny seedlings...|
Celery is a heavy-feeder and the soil you transplant into should be well-draining and relatively high in nitrogen and minerals.
Celery naturally grows flat on the ground (like a starfish - if seen from above). To get upright bunches (like you buy from a market) it must either be grown close together in a block, or in collars. In the first few years we grew celery, we used milk cartons and large soy-milk containers to keep the celery growing upright (see pics). The collars blocked the sun from getting to the celery and hence "blanched" it (kept it from getting too dark-green or tough). But we always had problems with slugs which found the collars to be a perfect habitat. For the last several years we've simply grown the celery close-enough together so each plant holds the others up that are around it. Spacing them about 8" apart seems to be the ideal distance. To use this method (without collars), plant them in a block or square (not a single row). They'll grow fine in a single row, they just won't grow upright and may be darker green and a little more fibrous.
|We used to use milk cartons (held in place with bamboo stakes in two corners) to keep celery upright - it tends to flop flat - and to blanch it (direct sun makes celery darker green and more fibrous) but the collars proved to be ideal slug habitat.|
|Now we plant the celery in "blocks" (not rows), 8" apart, and the plants hold each other upright. They're not quite as blanched as with the collars but it takes less time and we don't have problems with slugs or snails.|
|Late winter celery in our greenhouse. This has been harvested once and grown again.|
|Second-cutting of celery is often more coarse but also more flavorful. Chop finely to use in soups. "Mmm, good!"|
Nutritional content of celery: Celery is high in water and fiber-content and very low in calories. Since celery is mostly made of water (almost 95%), it is not particularly high in any one vitamin or mineral. Nevertheless, celery is a good source of vitamin K, with one cup containing about 30% of the recommended daily intake, according to the University of Michigan. Celery can also help you get enough folate, potassium, fiber and the micronutrient molybdenum. It contains small amounts of vitamin C, vitamin A and some B vitamins. "Celery is naturally low in calories, carbohydrates, fat and cholesterol," (Read full post here: Celery: Health benefits & nutrition facts)
|Always grow or buy organically grown celery. Having such a high water-content, it absorbs and retains pesticides and herbicides.|
As people tour our gardens, they commonly remark that they've never grown their own celery. We hope this post has helped demystify the process and we wish you much success with your growing.
And here's some more excellent guidance on growing celery from the National Gardening Association: How to Grow and Care for Celeries