Growing and Caring of Onions – How to Harvest Onions

Growing and Caring of Onions - How to Harvest Onions

Onion Plant – Allium Cepa 

Onions or Allium Cepa is a perennial annual plant which is native to China, Persia, India, Egypt and central Asian countries. The plant has hollow blushy green leaves and the begins to grow at the base of the plant. During the spring season, foliage may die and outer layers of the bulb become dry and brittle.

Onion varieties grow to a height of 8-18 inches tall and the leaves may appear in long, cylindrical, hollow stems.Onions are the popular vegetables as they have a wide variety of uses. They are very easy to grow, require very little space and harvested first in its growing season.

Though it has some medicinal health benefits, when you chop the onion it releases the chemical substances that irritate eyes and may start watering. It is mostly cultivated for its use in food like savory dishes, eaten raw or make pickles, chutneys, soups, curries, gravies, boiled, grilled, baked, fried and roasted.

Here in this article, we share about the growing, caring and harvesting of onions. If your onion plants are suffering from pests and diseases problem, we also come up with a solution to deter them and making your onion plants healthy, strong and bloom all year around.

Onion Varieties

S. No Variety Specification
1 Snow-white Round onions that weigh 1 pound
2 White Round, very  mild taste, matures 85 days
3 Yellow onions Mild taste, papery skin with pale golden color
4 Red Large size, red color skin
5 Green onions Immature onions, tall green shoots
                             Onion Plant Information | Growing Conditions

Name                                                 :               Onion

Family                                               :               Amaryllidaceae

Scientific Name                               :               Allium cepa

Origin                                                :               Central Asia

Soil                                                     :               Well-drain soil with pH 5.5 – 6.5

Sunlight                                            :               Full sun to partial shade

Plant Height                                    :               75 – 180 cms (2-6 feet)

Temperature                                    :               68 – 77F

Watering                                           :               Sufficient amounts

Fertilizers                                         :               NPK-fertilizers

Harvesting Time                             :               100-120 days

How to Grow Onions at Home?

To grow onions plants at home, you must start growing from seeds. As these are cold-season crops can easily grow at because of their hardiness. A step by step procedure is given below about how to grow onions from seed indoors…

  • Before planting, choose a hybrid variety onion that you would like to grow in pots at home indoors.
  • Make sure the onion seed you prefer to plant is healthy and must have the capability to produce a high yield crop gain.
  • Select an area or location with full sunlight where the growth of onions will not be damaged by the other neighboring plants. They can even grow in partial shade climatic conditions.
  • Place the onion seed in pots of size 6-8 inches at the beginning stage. The pot is made up of plastic, clay or ceramic and must have holes at the bottom to drain the water quickly. You can also use large containers if you wish to grow.
  • Well-drain, the loose rich fertile soil is suitable to grow onions plants.
  • Like other vegetables, they do best in slightly acidic soil. Ideal soil ph conditions to grow onions are 5.5 to 6.5. At this range, we can easily access the soil nutrients to plants.
  • Add the mulching agent (ripe fruits-vegetables and dead leaves) at the base to keep the soil moisture levels constantly and to improve the soil fertility.
  • Provide onion plants about 1 inch per week. For an optimal plant growth, the soil should not be soggy. Do not overwater the onion plants as it damages the plant growth and may even die.
  • Onions are adaptive to a wide range of temperatures and are frost tolerant. These plants establish leaves, roots, and bulbs in cool temperatures ranging from 55-75F.
  • These plants will not survive if the temperature drops below 20F. To maintain an optimum temperature of 68-77F to grow onion plants at home.
  • The seeds may take 7-10 days time to develop into seedlings when planted in small pots. It also depends on the climatic conditions the cooler the weather is the longer it takes for the seeds to germinate.
  • During seedlings time, it may be of few inches (2-3) height. Do not harm your seedlings as it will not grow properly and produces onions in less quantity.

Pests and Diseases

Pests Diseases
Onion maggots Botrytis leaf blight
Thrips Downey mildew
Armyworm Gray mold
Beetles Purple blotch
Onion fly Fusarium wilt
Spider mites Damping off
Leaf miners Root rot

Nutrient Deficiency

S. No Element Deficiency Symptom
1 Nitrogen Curl and erected yellowish green leaves
2 Potassium Bolting, dark green leaves
3 Calcium Reduces bulb size, slow growth
4 Phosphorus Slow growth, light green leaves, dried bulbs
5 Sulfur Chlorosis leaves completely turn yellow
6 Manganese Burn leafy tips, light color curlings at edges
7 Iron Yellowing of young leaves, interveinal chlorosis
8 Zinc Necrotic leaves, young leaves turn yellow


Onion plants are heavy feeders and they need a constant supply of fertilizers to produce big bulbs. They require a high source of nitrogen content to thrive quickly. The first application of fertilizers should be after 3 weeks from the time of planting. You can use the best fertilizer like fish emulsion, bone meal or compost tea,  Eggshells, aged manure, Epsom salt and Baking soda to improve the plant grows quickly.


When bulb matures pull out the soil for the bulb to expose to sunlight. If the onion bulbs are not developing out of the soil then you may need to remove soil to some extent, so that the roots and bottom part of the bulb are in the soil. This process helps the bulbs to dry faster.

Once the skin of onion bulbs are dried then it ready to harvest. Harvest the bulbs when they are 2-3 inches size and bend the plants to ground level to avoid top rooting of the bulbs. Now allow the bulbs to dry for 5-6 days and turn the brown color. After harvesting place, the bulbs in a well- ventilated warm container such as boxes or bags for a longer time.

How to Propagate Onions?

Onions produce pungent smell than any other vegetables in the garden. Though they are heavy feeder plants require a lot of care to handle them. There are many methods to propagate onions i.e. from bulbs and from onion sets or sprouts.

From Bulbs

You can easily propagate onion plants from bulbs as it takes less time for the plant to mature and bear healthy disease resistant big onions. To grow onions, start planting onion bulbs in fall or spring season.  Place them in a well-drain fertile soil about (1/2inch) depth and 8 inches apart between each bulb. Water the bulbs regularly in sufficient amounts. The bulb receives enough nutrients from the soil, sunlight and starts growing vigorously. It may take few months time to produce onions. If the clusters are in contact with the ground level, it can form clumps and try to separate them.

From Sprouts or Sets

You can also propagate onion plants from the sprouts or transplants or simply called sets. Once they are planted into the ground develops quickly and reaches maturity stage. Sets that are grown from the seeds are sown in the soil as soon as it produces bulbs. These immature bulbs are harvested after 10 weeks from planting and stored in its growing season.

Is onion a root or stem vegetable?

Onion is considered as a root vegetable because root vegetables grow underground and also absorbs high amounts of nutrients from the soil to thrive. The onion layers or the bulb of the onions contains as a modified stem in the center and leaves.

How long does it take to grow onions?

To grow onions from seeds start planting in early spring seasonGreen onions are ready to harvest after 20-30 days planting in soil whereas dry bulb onions take 100-175 days to reach harvesting stage.

How often do you water onion plants?

Water the plant regularly (day-to-day basis) throughout the year. If the soil is dry, water immediately after planting. Keep the soil moisture levels constant but not soggy. If you have planted in a well-drain soil, they need 1 inch of water per week to grow. Make sure you don’t overwater the plant as it may result from the plant to root rot and sometimes may even die.

Can you grow green onions in water?

Green onions are easy to regrow from kitchen scrap. For this, you just need to take the leftover onion roots and place them in a glass of water. The position is as such that the roots are pointing down. Place it in a sunny location and change the water in a glass for every couple of days. Within a week or so you will be able to see a new set of green onions. Harvest spicy onions and use it for cooking purposes.

What are the good onion companion plants?

Onion plants love to grow along with beets, Brussel sprouts, tomatoes, summer savory, lettuce, chamomile, strawberry, spinach, roses,   broccoli, cabbage,  peppers, carrots and potatoes . All these plants help to improve the plant growth and also deter pests, nutrient deficiency problems.

Like the good companions plants for onions, there are some plants that damage the growth of onions from blooming. Beans, peace, sage, asparagus, garlic, leeks utilize the soil nutrients and do not allow the onion plants to bloom.

Is onion plant poisonous to pets?

Onions contain a compound called thiosulphate which is toxic to both cats and dogs. When cats and dogs consume the onion leaves causes an indigestion condition called hemolytic anemia that damages the red blood cells in your loving pets. This toxic nature can also cause skin burns, irritations and may fall sick.

Onions Nutritional Information

On serving 100 grams of onions contains 40 calories, carbohydrates, proteins, and fats.  Onions are naturally cholesterol free and low in fats. They are a very good source of biotin and also contain manganese, phosphorus, dietary fiber, calcium, potassium, and magnesium.

Onion Health Benefits

Onions are a part of allium family and have been cultivated by farmers for many centuries for its flavor and medicinal properties. A study says that 105 billion pounds of onions are harvested every year worldwide. China ranks first in producing onions according to FAO-Food and Agricultural Organization of the United Nations. Here are some possible health benefits of consuming onions that includes cancer prevention, boosts mood, skin and hair growth.

  • High fiber intake can lower the risk of cancer. A study shows that consuming 7 servings per week can reduce the cancers like colorectal, prostate and stomach in humans.
  • The antibiotic and antiseptic properties of onions help to cure infections, wounds, skin problems. It also improves the quality of sleep and boosts the mood.
  • Consuming onions in required amounts helps to cure digestion, improves bone health, lower blood pressure, allergies, asthma, hypertension, arthritis, and cholesterol.

Growing and Caring of Onions - How to Harvest Onions

Start growing these pungent onions from bulbs that deter pests and also make your home garden a better place. If you have amazing ideas about growing onion plants, please share your experience with us.

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