Grow Onions In Container | Soil, Pots, Planting, Fertilizer, Care

Growing onions in containers in the home garden a lot easier. It is one of the best organically growable vegetables. This is one of the best vegetables for container gardening.  Because it not a taller plant (max 25inc) and it has a small root bowl than other plants. We can expect the harvest in 90-120 days (on average) after planting the seeds, transplants, sets, or cuttings scraps. This time change according to the onion varieties.

Onion is also called the bulb onion or common onion. There are several methods to grow onions at home. The easiest method is from scrap cuttings. It calls a plant an onion from an onion. It is a cheaper method and faster. This vegetable can grow all year round. Generally, it is not considered a seasonal vegetable. This is a perennial vegetable.

Different varieties have different flavors. These are some of the common varieties that we can find.

  • Red onion has a sweet taste and its bulb size goes from mid to large. This variety is also called purple onions. It mainly uses for salad, sandwiches, cooking, and pickling.
  • Yellow onion has a strong flavor. This variety is also called Spanish or brown onions. It is rich in sulfur contents. yellow onion is mainly used for sandwiches and salads.
  • White onions – These onions tend to have a mild flavor. It is a low sulfur content. It is used for soups, sauces, and salads recipes.
  • Shallots have mid-taste and have smaller bulbs. Its leaves also use as an ingredient for many cooking and deep fry recipes.
  • Green onions/scallions similar to the shallots and have a milder taste and have very small or no bulb. Green onions grow for leaves harvesting purposes.

Growing onions in containers

How To Grow Onions in Containers.

Onion Potting mix.

Onions love well drainage sandy loamy soil mixture. You can use your own homemade organic compost with chicken manure for this. The most important thing is your soil mixture should loose. It grows well in organic soil and requires less fertilizer. Onions will grow in slightly acidic soil which is ph5.5 to 6.5. It can grow in clay sand, but it is not recommended. If the soil keeps too much moisture, it will rot the root and onion bulb.

When growing onions in containers best Onion soil recipe is,

Make sure that your soil does not consist of any rocks. Adding leaf mulch also beneficial to prevent small grass from growing. Not only that it improves the organic materials. Adding chicken manure will provide Nitrogen, Phosphorus, and Potassium which are essential for growing the leaves and bulbs. Increasing the chicken manure will improve the nitrogen level, but adding too much not good at all. It reduces the strength of stems.

See also  Why Is My Aloe Vera Plant Turning Yellow Green?


Onion sunlight requirement.

Like other edible plants, the onion plants require to grow a good root system, with good foliage before developing their onion bulb. So daylight is highly affecting the form of bulbs. According to that, there are mainly three types of onions around the world. They are,

  • Short-day onions require 10-12 hours of daylight for forming the bulbs. Best in warmer climates. The suitable time to plant is fall, harvest in late spring. USDA zone 7 or higher regions. The southern part of the USA and the UK are most suitable. Also in Australia Queensland and New South Wales.
  • Day-neutral onions: varieties also called Intermediate onions. It needs 12-14 hours of daylight for producing the bulbs. Suitable for zones 5-6. Plant in fall and can collect harvest in mid-winter. These varieties grow anywhere in the world except too the humidity area.
  • Long-day onions: grow best in 14-16 hours of daylight area. The best time to plant in early spring. Suitable for zone 6 and lower regions. This means colder climates like Northern America, Canada, the northern part of the UK.

When selecting the onions plants or seeds, you have to carefully read the packet instruction to select the right variety.

The best-growing temperature is 55° to 75°F (13-24°C). It need cool dry climate condition and not like wet soil and humidity. This is one of the rapidly growing vegetables. Although some varieties can grow even 77°F (25°C) or higher temperature.

When growing onion indoor, especially in a greenhouse, you can provide the necessary light by supplementing LED growing lights. But it does not require 24×7. According to the above day-light requirement, you have to provide. It needs a few dark hours. If the onion plant becomes a pal and stretches it require more light.


Onion Water requirements.

This plant requires plenty of water to grow bulbs. Though daily watering does not require for this plant. When the surface soil is dried, you can start the water. Dig a dried stick around 2 inches deeper and check if it has enough moisture. If it has moist no need for water. To harvest sweeter onions, you have to use more water. Overwatering can cause root rot and increase fungal disease activities. Before water always check the surface moisture level.

When adding the leaf mulch to the soil surface, it reduces the water evaporation and keeps the surface moisture. So it needs less water. It is more useful to keep the water during the drought and summer.



Regular fertilizer is not required. Adding organic compost during the planting of sprouted onions is sufficient for the growth of the plant.


Onion growing method.

We can get plants by using seeds, sets, transplants, or either cuttings scraps. Onion sets are young alive bulbs harvested from the previous cultivation season. Transplants are small dormant seedlings just like the scallions and might appear pale. They grow perfectly once they planted. Growing from seeds need more time. The fastest-growing methods are transplants or cutting scraps.


Can you grow onion from an onion?

Yes, you can grow onions from onions. In every onion bulb, we can get one to three plants. In this method, we cut the bottom root area and submerge it in a water container to sprout out and then plant it in the onion potting mix. This method called the scrap cutting method and it is one of the fasted growing methods. If you go for commercial cultivation, the best method is growing onions from seeds, sets, or transplants. Below you can get more details about growing cuttings.

See also  How To Care ZZ Plant - Zamioculcas Zamiifolia


Grow Onions from scrap cuttings.

Cut the onion 1 to 0.5 inches (2.54 to 1.27 cm) from the bottom root area. Then take off only the dried covers, not remove any dried roots. To sprout onion, place the cut scraps on water containers and make sure that bottom root parts submerge. Onion sprouting requires to touch the root area with the water. Within 10 days, it starts to sprout, you can start planting sprouted onions in containers with the correct potting mix.

Onion scrap cuttings for sprout

How to Planting onions in containers.

How to planting sprouted onions?

Once the onion sprouts out and you can see small green buds. Depending on the scraps it can be several sprouts. Now you can start planting sprouted onions in containers.

Dig an individual hole for each sprouted onions and place the green part upward direction and cover it with soil. After planted sprouts add leaf mulch to retain the moisture for a longer time. It is beneficial for the growth of the root system.


How to plant onion transplants.

Normally these transplants come as a bundle. First, separate them apart. Depending on the transplant root length, dig a hole in the onion growing container. Typically these plants 2-3 inch length roots. Once you planted onion water well.


Growing onions in containers.

Can you grow onions in a pot?

When growing onion indoor, grow onions in a pot is the best method. First, you have to consider the pot dimension and depth. More than 9-inch depth pots are enough. Diameter depends on how many onions plants that you going to grow. For a single plant, it requires 6 inches in diameter. The best economical method is planting many onions in a single pot. By selecting wider pots, you can collect decent crops. Space between each plant is important. If there is not enough space between the onion plants, it results in small onion bulbs.

Onion growing containers requirement.

  • More than 9- inches depth.
  • Select wider pots for harvest decent crops (for growing many onion plants).
  • Require good drainage, so make sure that it has enough drain holes.


Onion Plants Space Requirement.

Space between the plants is more important especially growing onions in containers as well as the ground. If there, is not enough space, it makes overcrowding and results in smaller bulbs. Onion plant’s space requirements vary according to the plant’s variety.

  • Green onions/Scallion plant space between the plants is 2 inches. Because these plants do not develop large bulbs. It mainly uses for harvest leaves.
  • Red, White, and other onions: These varieties need around 6 inches of space in-between the plants. (Red onion, etc.) and 9-12 inches row spacing.
  • Shallot onions plants’ space requirement is 7 inches, even if it generates smaller bulbs. Because a single plant can produce several small bulbs cluster.
See also  How to Care Aloe Vera Plant At Home - 8 Tips


How to get big onion bulbs.

There are few requirements to get bigger onion bulbs when growing onions in containers in your indoor garden.

  • Enough space between each plant. So each plant bulbs do not touch each other and plants can absorb enough nutrition from the soil.
  • Sandy loamy soil mixture. When the soil mixes too much hard (close to the clay), bulbs forming slowly and produce small onion bulbs. Loose soil is perfect.
  • Remove seeds pods. Cut them when it starts growing unless you need them for replanting. Because the plant starts using all the energy to grow its seeds. Trimming onions for bigger bulbs
  • More organic nitrogen fertilizer: As I said earlier, adding more nitrogen-rich organic compost fertilizer improves bigger onions bulbs. Chicken manure is high in organic nitrogen. Adding more leaf gives extra ring to an onion. Which means more leaves bigger bulbs.
  • Plant at right time: Planting onion sprouts at the right time to harvest bigger onion bulbs. The best time to plant onions plants in early spring or fall.
  • Mulch: For onions to grow bigger it requires good nutrition and water. Adding leaf mulch prevents weeds from stealing nutrients and reduce water evaporation.


How long do onions take to grow?

Generally, it takes 90 to 120 days to harvest the onions, right after plant the seeds/cuttings. In a year, you can grow onion two or three times, If you can manage the climate conditions (using a greenhouse) or the seasonal effect is low. There is a slight difference in each variety and planting method.

  • Red onion bulbs growing time is generally 90-120 days from the planting. Different red onion varieties have slightly different maturity dates. All of them fall within these three to four-month periods.
  • Green onion growing time 60-80 days after the planting. This is one of the rapidly growing varieties in the onion family. You can expect a fully grown harvest after 80 days. That is similar to 2 to 3 months of maturity time. Depending on the climate condition and family variety its time slightly changes.
  • Shallots onion bulbs growing time is around 80 – 90 days from the planting. After that, the maturity it can be harvested. This time change according to the selected variety and climate conditions.
  • White onion bulbs growing time around 100-120 days after the planting. But its time depends on its variety and daylight. It time growing time similar to the red onion.
  • Yellow onions growing time around 80-110 days from the planting. You can pick the bulbs after 3 to 4 months. This period varies slightly depending on the variety and climatic factors that affect the plant.


When to harvest onions?

You have to wait until the plant gets fully mature for harvesting onions. When the plant’s leaves are fallback and beginning to die, that is the right time to pluck the onion bulbs from the plant. When onions ready to harvest just pull the plant from the sand.


How to grow onions in the water?

Onion can grow without the soil. However, in a colder environment, this is not a good alternative growing method.

Leave a Comment!

error: Content is protected !!