Planting onions in the fall is the most effective means of propagation, whether or not you buy specific fall onions. There are various methods for planting fall onions successfully and this article explores their respective pros and cons. I would like to discuss how to plant fall onions and avoid common issues associated with planting them in spring.
What are Fall Onions?
Before going on how to plant fall onions let us discuss what is fall onions. Fall onions refer to onion sets planted during autumn. Most short-day and intermediate varieties perform best when planted between late September and early October before temperatures begin to decrease and day length shortens.
Due to shorter days, bulb growth doesn’t begin as soon as expected but instead leaves and roots will begin forming, giving fall onions an advantage over spring planted onions.
There are certain onion varieties specifically sold as fall onions due to their increased frost tolerance, meaning they can remain outdoors over winter without fear of frost damage. Others should be planted in pots or modules and stored inside your greenhouse or kitchen windowsill during their dormant period in winter to minimize frost risks.
How to Grow Fall Onions?
Let us talk about the details of how to plant fall onions:
When to plant fall onions
The most important thing to start with how to plant fall onions is also when to plant fall onions. It is recommended to plant fall onions between September and October or if, as I did, we experience mild early winter conditions they can even be planted up until November as long as there is ample time for roots to form before their first frost arrives.
Wherever you plant spring onions, take great care not to damage their root plates by pushing too heavily or compacting their soil as this could prevent new roots from sprouting into the surrounding earth.
Planting Fall Onions In Modules
Are you looking for how to plant fall onions? One way is planting fall onions in modules. Module trays provide the most space-effective means of planting fall onions. Their root plates need enough room to develop without expending too much energy or trying to grow too rapidly (especially if planted in early September when day length may still permit rapid bulb growth before dormancy kicks in).
By seed-starting in modules or seed trays first, planting onions reduces the risk of being pulled up by curious birds who mistake brown tips for worms or by squirrels who mistake your bulb for tulips or cashed nuts and pull it up whole from its soil resting place.
To plant in modules, fill half the modules or seed tray with potting soil before gently placing bulbs with their points facing up in them, making sure not to cover too much ground around each one, just enough so it doesn’t topple over! To protect from further tipping over, allow soil around each bulb just enough to stop it from tipping over in its pot.
Tip: For beginners looking to start modules, here is my recommended size of seedling trays if growing seeds indoors. Make sure that corresponding watering trays are also purchased. Also, see this resource list with all of the tools required.
Root development should take priority here; plant out in March after the last frost has subsided for best results. One common challenge associated with fall onions grown in modules is damp shock; they often end up waterlogged and drowned if planted too early outdoors.
Planting Fall Onions In The Ground
Another way in how to plant fall onions is planting fall onions directly in the ground. Direct planting allows you to make use of otherwise vacant beds during winter, helping retain nutrients which could otherwise be washed away with heavy winter rainfall and wash away with its intensity. Furthermore, planting directly allows fall onions to establish roots faster in their permanent position, speeding up this process even more rapidly!
To plant fall onions in September or October, simply dig a shallow trench and insert onion sets so that their tips remain visible above the soil surface.
Care of Fall Onion Sets
After learning how to plant fall onions, also learn care of fall onions. Once fall onions have been planted, topping is an effective way of stimulating root development throughout winter. We offer an in-depth guide here but in essence, by regularly cutting back leafy growth between autumn and winter a bulb’s energy is diverted towards producing stronger roots rather than maintaining leaf growth on top of its body.
As soon as it comes time to plant them out in their final positions in spring (or when days lengthen for sets planted directly in fall), stop trimming leaves and add nitrogen-rich fertilizer or coffee grounds into their soil, such as coffee grounds for maximum leaf development until summer when bulbs will begin forming properly. This ensures a healthier leaf canopy until summer arrives when bulbs can start growing to maturity and bulbs need time to mature properly before blooming properly themselves.
Fertilize regularly throughout summer by applying potash and phosphorus-rich plant food like fruit peel or bone meal to promote larger bulbs with stronger root systems.
When To Harvest Fall Onions?
After successfully learning how to plant fall onions, now its time to harvest. Harvest your fall onions between late August and early September, earlier than spring-planted varieties due to their extended root systems that absorb more nutrients in their first days in soil.
Spring-planted onions start producing bulbs at about the same time; however, due to stronger roots, they produce larger bulbs more rapidly and efficiently. Keep an eye out in August for any dropping leaves that have started becoming papery or have bent over as this indicates when your onions may be ready for harvesting.
Best 5 Fall Onions To Grow
After knowing how to plant fall onions, let us discuss the 5 types of fall onions:
- Red Winter Fall Onion: A crisp, sweet pink onion that overwinters well. Ideal for salads in late summer as well as being stored and cooked into casseroles over winter after planting.
- Shakespeare Fall Onion: A new variety we tried this year was Shakespeare Fall Onions and have seen them thrive quickly when germinated outdoors. Their large bulbs produce high yields with reliable yields. Plus their thick brown skin stores very well when dried properly for storage purposes!
- Autumn Gold Fall Onions: It can make great competition growers due to their uniform round bulbs which produce perfect spheres with uniform growth patterns. Their superior bolt resistance also means easier care during hotter summer months as you won’t require as much topping or leaf restriction to prevent bolting.
- Rader Fall Onion: A timeless favorite, Rader onion has an iconic brown-yellow skin encasing white set rings which produce mild flavorful relishes and BBQ dishes alike. Additionally, these hardy varieties make excellent choices to plant directly in soil even during extreme winter temperatures!
- Snowball Fall Onion: This beautiful white-skinned onion features a mild allium flavor for convenient stewing or casserole usage. Perfect for creating exquisite allium dishes!
Also read about Storing leeks for winter
Conclusion
Now you should be aware of how to plant fall onions. Growing autumn onions isn’t overly difficult once you understand their growth habits and the reasons behind planting sets of them in the first place. As I made my inaugural foray into growing fall onions, I quickly made many mistakes from overwatering to hasty planting, all of which can spell doom for any attempt at success.
If I were to choose one tip for planting them successfully, it would have to be planting modules in October and planting in the ground in March. This allows your seedlings to take advantage of their dormant period while also keeping their drainage optimal until spring arrives and you need a boost for their revival.