Growing Celery – Get an Early Start!
Gardeners begin to get the seed starting itch in February. Here in Saskatoon, for most flowers and vegetables, February might be a bit early. Regarding vegetables though, the exception to the statement above are Brussel sprouts, cauliflower, hot peppers, celeriac and celery. And yes, you can grow celery in Saskatchewan! Many of us know this already but if you are just new to vegetable gardening and starting seeds, this may come as breaking news!
Way back in the day, celery was used as a medicinal herb by the Egyptians and Greeks. It was used to treat colds, poor digestion, bouts of flu, arthritis, water retention and liver /spleen ailments. Wild Celery was native to the Mediterranean and grew in boggy soil. Celery has been found in Egyptian Pharoah’s tombs and Romans used it in cooking. In the 1600s, France followed suit and began to use it as part of their diet.
Celery (Apium graveolens) is a cool weather, long season crop. The Latin name means ‘strong smelling’. It is a member of the carrot family (Apiaceae or Umbelliferae). The soil must be kept moist at all times. Celery is a biennial and has very similar flowers to carrots which are biennial as well. If you are a bit heavy handed with watering, this is your plant! It is divided into three types; green stalk, leaf and celeriac.
Today, celery is used primarily for dipping, soups, salads, stir fries and in stuffing. Home grown celery is very flavorful and most varieties have a high fibre content (strings). It is also full of Vitamins A, K, C and is a source of calcium and potassium. Celery contains coumarin and acetylenics. These are compounds that help inhibit the development of cancer cells. Celery is well known as a diuretic due to its high salt content. It has no significant disease problems other than the possibility of aster yellows; a disease spread by leafhoppers.
This DIY is about starting green stalk celery seeds (Apium graveolens var. dulce) and growing them on in your garden. Let’s get started!
Celery seed should be started inside 10-14 weeks ahead of the projected last frost date. At best, the seed has a 55% germination rate so don’t be discouraged if only a few of your seeds produce plants. Celery seeds are very fine so there is usually quite a few in a pack. Pelleted seed is available which helps to save time on thinning in the future. The shelf life of a packet of seeds is usually three to four years if kept in the dark in an air tight container. Celery days to harvest is roughly 100-120 days dependent on the variety. Some new varieties have shorter days to harvest which is a bonus for our climate. This is a good time to buy a grow light set-up with a timer as grow lights provide consistent light and keep the celery plants compact from the start.
To begin, it is recommended that you can use a new or used seed starting tray. No matter what container you choose, it must be washed with soap and water and soaked for 20 minutes in a 9 parts water to 1 part bleach solution. This disinfects the container and goes along way in preventing damping off disease. Make sure your containers have good drainage and fill them with a quality, pre-moistened, seed starting mix. Preferably a mix that has some nutrient in it that will sustain the seedlings until they are transplanted into four inch pots.
Lightly tamp down the soil surface and cover it with a very fine layer of pre-moistened vermiculite. Celery seed is very fine and the vermiculite holds the seed in place and slowly releases moisture around it. It also comes in pelleted form which takes the chore out of thinning after germination. Celery needs light to germinate so do not cover it with more starting mix. Mist and cover your containers with plastic wrap or a transparent tray lid and place them in a bright light location. A room temperature of approximately 21 degrees is recommended.
It is very important to keep the soil moist but never soggy. Check the seeds for germination daily but you may not have to mist/water them daily. Germination time varies but most celery seed will germinate in 10-12 days. Some varieties can take up to 3 weeks.
When seedlings are at the six leaf stage, gently prick out and separate the strongest ones from the group. Carefully transplant each seedling into four inch pots that contain a rich soil mix. Make sure that the four inch pots have drainage holes.
If the soil in your four inch pots contains nutrient, there is no need to fertilize as the seedlings grow. If not, feed established four inch pots every two weeks or so with an application of water soluble vegetable fertilizer or a fertilizer high in nitrogen.
When outdoor temperatures are consistently above 13 degrees C and your garden soil is 10 degrees C or above, transplant your celery starts outside into fertile, humus rich soil in a sunny garden location. The soil should be neutral to slightly on the acidic side (pH 6-7). Be sure to harden off your seedlings for a week or so before putting them outside full time. If you put celery seedlings out too early in the garden, they may become cold and bolt (go to seed). Bolting may also occur if the plants are under watered and/or in high heat for too many days.
Do not plant celery close to carrots and parsnips as they all compete for the same nutrients and share the same pests. The root vegetables may also interfere with the celery root system. Companion plants for celery can be beans, cabbage, chives, leeks, nasturtiums, spinach and tomatoes.
Ideally celery can be planted between two taller veggie rows such as leeks, tomatoes and bush beans. These plants will keep the slower growing celery shaded in the afternoon. If you choose to grow just a few transplants, consider a 30-35 cm large container filled with rich soil and has good drainage. Four transplants per large container is recommended. If you are growing in a raised bed, plant 20-25 cm apart on center.
Some gardeners plant their celery plants fairly close together in a block (3 x 3) so that the plants shade each other’s stalks which helps create a milder tasting celery.
You may have heard about the trench method of planting celery. I am not a big fan of this method as it involves more work than I like to devote to the process. Also more self-blanching cultivars are coming out onto the seed market that avoids the process of blanching all together.
Celery is a heavy feeder and needs to be kept moist as it grows. The standard recommendation is two inches of water a week; more if the days are very hot. A layer of compost around each plant after transplant provides lots of nutrient and helps to hold in moisture. Continue to fertilize every two weeks and halfway through the growing season with a water soluble vegetable fertilizer. After planting out, it is also a good time to put in a drip irrigation system around the celery plants. If the weather gets too hot, you may have to go back to hand watering. Water celery at ground level so all the water gets to the root system. If your celery plants dry out, they will develop a bitter taste.
The process of blanching (or whitening) celery stalks should start three weeks before harvest. Blanching reduces the bitter taste of green celery stalks. Encircle the bare stalks of each plant up to the base of the leaves with pre-folded cardboard or waxed milk cartons and tie in place. When you remove the cover at harvest do not worry if a few leaves have yellowed. This is due to a lack of sun and will not affect the quality of the plant. If you have planted a self-blanching variety such as Tall Utah 52-70 or Golden Self-Blanching, you can skip this step altogether.
A day before harvest, water your celery heavily so it can take up the maximum amount of water it can hold in its stalks. This will ensure good flavor and texture. Cut bunches off at soil level.
Green stalk celery can be stored as close to 0 degrees C as possible. Provide high humidity and good air flow around each bunch.
Check out these Celery varieties/cultivars for your growing pleasure:
Tall Utah 52-70 – A heirloom variety. 20-30 days germination. 100 days to maturity. Bonus: Does not require blanching. Grows well with lettuce, spinach and peas.
Victoria – Pelleted seed. A bolt resistant variety. 100 days to maturity.
Tango – A stringless celery. 20-30 days germination. 85 days to maturity.
Golden Self-Blanching – a dwarf heirloom variety from Europe. 7-21 days germination. 90 to 120 days to maturity. It is still advisable to keep as much full sun off the stalks of self-
blanching varieties as possible, so place your plants between companion plant rows or in block formation as described previously.
Merengo – F1 hybrid. 14-21 days germination. 80 days to maturity. Has high disease resistance.
Redventure - Stalks are red in color, fading to light pink. 20-30 days germination. 100-110
days to maturity.
Celery is also sold as pre-started transplants in the spring.
Keep an eye out for slugs. They love celery too!
Velcro strips will gently hold the stalks vertical while growing.
Yes, you can use an outside stalk or two from the celery plants as they are growing.
Celery can tolerate a very light fall frost.
You can freeze celery but it will lose its crispness. It is still good for cooking various dishes. Blanch 1 inch pieces of celery in boiling water for 3 minutes or you can wash the stalks thoroughly, chop and freeze as is.
Bonus: The nutritional value of celery is not affected by the cooking process.