Water Requirements For Onions
Onion plants need at least 4 inches (10 cm) of water per week during dry season. During wet season they require 8 to 10 inches (20 to 25 cm).
You can use drip irrigation or sprinkler irrigation. If you are using drip irrigation, make sure that it is not too close to your house because it may cause damage if there is a flood. Sprinklers are easy to operate but have their own problems. You must keep them away from your house.
If you want to grow onions indoors, then you will need to provide enough humidity inside the greenhouse. If you do not have any humidifier, then you can place some pebbles in the room where onion plants are growing.
These pebbles will act as a natural air conditioner for your home.
You can also use a fan to blow fresh air into the room where onion plants are growing. But remember that it is better to avoid blowing hot air directly on your house since it might cause fire hazard.
When you want to water your onions, you can either pour water over the soil or you can put some kind of container with water inside the garden bed and cover it up with dirt. The water in the container must be changed every three days.
This is called sub surface irrigation.
An expert claims that people living in dry places can grow onions by growing them under black plastic mulch. It helps to conserve moisture.
Onion plants grow best in full sun or at least 6 hours of direct sun light per day. If you are growing onion plants from seeds, then cover the soil with a dark cloth until they are 2 to 3 inches (5 to 7.5 cm) tall.
How often to water onion seedlings?
Onion seedlings should be watered with about 3/4 of an inch (2 cm) of water at least twice a week. If you have too much water, then you will end up having a lot of fungus problems.
Irrigating onions using Furrow
You can grow your onion plants using furrows. You need to dig furrows around your onion plants.
There should be enough space between each row and also between each onion seedling.
You will need to fill the furrows with water. It is better to use sub-surface irrigation for this purpose.
A mulch of compost around the plants will help keep weeds away and will also conserve moisture. Adding some fertilizer will also help your onions grow quicker and larger.
If you have chosen to grow your onions from sets, then the process is easier. Set the sets about 6 inches (15 cm) apart and cover them with 3 inches (8 cm) of soil.
Keep them moist until they start growing.
Irrigating onions in your garden bed
This process is similar to furrowing method explained above. The only difference is that you don’t need to dig furrows.
You will need to cover the soil with some plastic, black sheet, or use mulch to keep the soil moist.
You will have to water the soil whenever it is dry. If the weather is hot and sunny, then you will probably have to water your onions every day.
If you don’t have enough time to water your onions daily, then make sure that at least the top few inches (2-3 cm) of soil remains moist at all times.
Onions are heavy feeders. You will need to add some fertilizer to the soil before planting the seeds or sets.
You can use chicken manure, compost, or blood meal for this purpose.
How to prevent your onions from sprouting in storage?
You don’t want your onions to sprout or start growing while they are in storage. This process is called re-germination. It is better to place a few dry seeds in the container in case you need to replace some onions that have gone bad.
A dry, warm room is the best place to store your onions. The temperature should be between 70 and 80 F (21-27 C).
Onions can also be stored under proper conditions in a root cellar. Typically, a root cellar is located close to the house and has cool floors and walls.
The temperature should be between 45 and 55 F (7-13 C).
The USDA also recommends spraying your onions with copper sulfate (which can be bought at garden supply centers) 10 days before you need to put them away. Copper sulfate prevents the onion roots from growing.
Onions left in the ground in a cool, dry place will last much longer than those stored in boxes in a root cellar or shed. In fact, removing onions from the ground and leaving them lying around not properly cared for in general will increase the chances of them sprouting.
Onions are ready to be taken from the ground when the green part starts to turn yellow and falls off easily. If left in the ground too long, the onion will start to sprout in storage.
Harvesting and Storing Garlic
Garlic plants are generally ready to be harvested in late summer or early fall. You can tell the garlic is ready if you see whitish-blue bulbs begin to bulge just under the soil.
Garlic can be stored for months in dry, cool conditions. It can be braided and hung up to keep it free of dirt and keep rodents away.
Garlic can also be dried out, though this process will take a few days. Spread the garlic cloves on screens so that air can circulate.
After 2 or 3 days, the garlic is dry enough to be stored.
Storing Onions and Garlic in Containers
If you plan on storing your onions and garlic in containers such as a box or bag, first treat the container by painting it with several coats of paste wax.
You can put onions and garlic in the same container as long as they are separated so they don’t touch one another. You can also put dried grass, hay, or shredded paper between the layers of garlic and onions.
If you are separating your garlic and onions, place the garlic on the bottom and cover it with a layer of dried grass. Then place the onions on top and cover them with more dry grass.
Alternate layers of grass and onions until the container is full. Cover the last layer with more grass, paper, or hay.
If you are storing onions and garlic in a wooden box, punch holes in the bottom of the box and cover them with small pieces of wire screen. This prevents moisture from gathered in the container.
Storing Onions and Garlic in the Ground
You can also leave your onions and garlic in the ground until you need them. However, you need to remove both from the ground and dry them out before you put them away in storage.
After the last hard frost, allow the tops of the onions and garlic to die back naturally. Leave them in place and cover them with a thick layer of straw.
The roots will remain alive until you need to dig them up.
To harvest, loosen the soil with a garden fork and gently pull the bulbs free of the ground. Clean and dry them off and then gently brush the dirt from their skins.
Don’t wash your garlic and onions as it will encourage mold or fungus to form.
As you gather and clean your onions and garlic, spread them out on a tarp in a well-ventilated area. Turn them over once a day so that they can dry evenly.
Smaller varieties like new purple globs can be dried in 2 weeks. Larger onions like storage onions may take 4 or 5 weeks to dry.
Storing Garlic and Onions in the Paper Bag Method
This is a good way to store a small amount of garlic or onions for less than a year. This method is not recommended for long-term storage because the vegetables can begin to mold after several months.
To prepare your garlic and onions for storage, leave them out until they are dry.
Then place them in a brown paper bag. Do not use plastic, as it will cause the garlic and onions to get soft.
Place the bag in a dry, cool area like a cupboard or closet shelf.
In late summer, you can begin to harvest your garlic. The garlic is ready when most of the leaves turn brown and begin to fall over.
The entire plant will be nearly bare.
Your goal is to remove the entire green part of the plant so that all that remains is the bulb and the roots. This step is very important since the green plant will continue to eat nutrients from the bulb and will cause it to decay.
To harvest, trim 1 to 2 inches off the top. Place the trimmed plants on a tarp or sheet so that you can keep track of which bulbs are ready.
Over the course of a week, the garlic will begin to sprout a little green stalk. When this happens, the garlic is ready to be dug up.
To remove it from the ground, gently dig around the base until you can grab hold of the bulb. Carefully lift it from the soil and trim the roots off.
Spread the bulbs out on a tarp or table with good air circulation to dry for 1 to 2 weeks.
Sources & references used in this article:
Comparison of sprinkler, trickle and furrow irrigation efficiencies for onion production by MS Al-Jamal, S Ball, TW Sammis – Agricultural water management, 2001 – Elsevier
Subsurface drip irrigation of onions: Effects of drip tape emitter spacing on yield and quality by J Enciso, J Jifon, B Wiedenfeld – Agricultural water management, 2007 – Elsevier
Onion yield and quality response to two irrigation scheduling strategies by J Enciso, B Wiedenfeld, J Jifon, S Nelson – Scientia horticulturae, 2009 – Elsevier
Effect of planting methods and irrigation levels on water productivity of onion (Allium cepa L.) by MS Kahlon – Indian Journal of Agricultural Research, 2017 – indianjournals.com
Water and nitrate movement in drip-irrigated onion under fertigation and irrigation treatments by TBS Rajput, N Patel – Agricultural Water Management, 2006 – Elsevier
Productivity of onions using subsurface drip irrigation versus furrow irrigation systems with an internet based irrigation scheduling program by J Enciso, J Jifon, J Anciso, L Ribera – International Journal of …, 2015 – hindawi.com
Onion cultivation in subtropical climates by JN Corgan, N Kedar – CRC Press. Boca Raton, 1990 – books.google.com
Nitrogen use efficiency and onion yield increased with a polymer-coated nitrogen source by D Drost, R Koenig, T Tindall – HortScience, 2002 – journals.ashs.org
Onion seed production in California by R Voss, M Murray, K Bradford, K Mayberry, I Miller – 2013 – books.google.com