Onions are always a great crop to plant in your backyard garden. They taste much better when they are homegrown and are essential in countless recipes. Despite this however, growing onions is not without its obstacles. Too often, the green stems of the onion plants will collapse under their own weight and cause the onion plants to droop.
So why are your onions falling over and drooping? Onions that droop are a signal that they are ready to be harvested. When onions are ready for harvest, the leaves will become flaccid as they are no longer taking in nutrients. The onion is done growing and should be harvested.
Often times however, onion plants will droop when the onion bulb is still relatively small in size. It can be pretty disappointing to see your onions ready for harvesting when they are only around the size of a golf ball, so here are some tips for growing larger onions in your garden.
Long day vs. Short day Onions
Onions can be divided into two different categories: long day onions and short day onions. When it comes to growing larger onions, choosing the right onion for your zone is crucial.
Long day onions require 14-16 hours of sunlight everyday and can grow anywhere above the 32° latitude line. Short day onions require 10-12 hours of sunlight and can be grown anywhere below the 32° latitude line. Planting a long day onion in a short day zone or vice versa will prevent the onion bulb from forming.
Therefore, you must determine whether your onion seeds or sets are long day or short day onions prior to planting if you expect to harvest a large onion bulb from your garden.
There is also a third category of onions called “intermediate day onions” Intermediate day onions typically grow between the 32° and 42° latitude lines. While these onions will grow within that zone, it is recommended that you grow a long day or a short day onion instead. While intermediate day onions do bulb, they don’t get as large as a long or short day onion would if grown in the right zone.
Onion Seeds vs. Onion Sets
When it comes to growing onions, the two main ways of starting them are from onions seeds or from onions sets. Both have their pros and cons, but if your goal is to grow larger onions, seeds are the way to go.
Starting your onions from seeds will almost always produce larger onions. This is because onions are biannual plants. When you plant an onion set, it is in its second year of growing. This means that it will spend a significant portion of energy in growing a flower to produce seeds rather than focusing on growing a larger bulb. In fact, an onion plant that goes to flower can reduce that size of its onion bulb by up to 25%.
Since onions started from seeds are only in their first year of growing, they can focus much more energy into developing a larger bulb rather than producing a flower that has seeds for next generation. Therefore onions seeds are a better option for growing larger onions. Just be sure to plant them at the appropriate time as seeds take much longer to grow compared to onion sets.
Using a Tomato Cage for Support:
As onions grow, their leaves often become top heavy and fall over. The weight of these leaves dragging down the plant can eventually cause the entire onion plant to droop. As stated earlier, when the onion plant drops it is done growing and it’s time to harvest. However, preventing the leaves from falling over will extend its growing life and thus allow the onion more time to grow even larger.
This is where using a tomato cage can help. By placing a tomato cage around the base of an onion plant, you can help support the leaves of the onion and prevent it from falling over. Onions should always be growing upwards so using a tomato cage for support can allow for onions to grow larger than ever before.
The Best Fertilizer for Onions
A large onion is a well fertilized onion. Of course, most fertilizers are beneficial and help your onions grow however, some are certainly more beneficial than others.
When selecting a fertilizer for your onions, look for a nitrogen rich fertilizer. Nitrogen allows for more leaf growth which in turn will take in more sunlight energy that will help develop a larger onion bulb.
A great example of a good nitrogen based fertilizer is blood meal. Blood meal is an organic fertilizer that comes in a powder created from dried animal blood. It typically contains around 13 to 15% nitrogen and is widely known as the best non-synthetic nitrogen based fertilizer. I personally use blood meal in my backyard garden and I have had huge success with my garden every season I use it.
Many gardeners believe that a phosphorus based fertilizer is the best kind of fertilizer for growing big onions. The reasoning behind this is that phosphorous helps in the growth and development of plant roots and many believe the onion bulb to be a part of the root. In reality, the bulb is actually a part of the onion leaf.
So while phosphorous is beneficial for onions, a nitrogen based fertilizer is the way to go. Nitrogen will help in the growth and development of your onion plant’s leaves. Every leaf on an onion plant is another layer to your onion. Therefore, more leaves equals larger onions.
Why are my Onions Flowering? When an onion plant begins to reach the end of its life cycle, it will develop a flower that will produce onion seeds for the next generation. In stressful conditions such as excessive heat or cold, an onion plant will develop a flower prematurely so that it can reproduce before it dies. This is known as “bolting”.
If you onions begin to bolt, cut off the developing flowers and harvest the onions. If your onions have not bolted yet, you can prevent future bolting by ensuring your onions are getting enough water and are not exposed to excessive heat or freezing temperatures. The optimal soil temperature for growing onions is between 68° and 77°F (20° to 25°C)
Are Onion Flowers Edible? Onion flowers are edible. They are known to have a sweet, pungent onion flavor to them. Some say the onion flower has a stronger onion flavor than the onion itself. If your onion begins to flower, you can pick off to buds and eat them. No preparation required!
Why are my Onions turning Yellow? If the leaves of your onion are turning yellow, they are most likely suffering from a lack of water. Be sure to water your onions regularly and keep the soil moist. If your onions continue to turn yellow, they may be victim to disease. Clip off the onion leaves that have yellow spots on them. If most all of the leaves are yellowing harvest the onion.