Is Growing Large Onions in Containers Possible?
|Organic Yellow Onions.|
Basics for Onion Plant Care -
When you take on the task of growing large onions in containers, there are a lot of factors that can influence the overall productivity of your plants. Oftentimes, when growth and yields are less than satisfactory, one of the following three requirements may not have been fulfilled properly:
- Selecting the Correct Type - Large bulb onions are broken down into two types, long day and short day. Short day onions are generally good for growth in southern latitudes, where long day types are normally grown in northern latitudes. It's important to find out which varieties grow best in your area. To ensure the greatest success, obtain seed or onion sets that were locally grown and already suited for your climate.
- Rich Fertile Soil - Although onions have rather small and shallow root systems, they are extremely heavy feeders. To maximize onion production, choose a potting soil high in composted organics. Further amending the potting soil using a 1:1 ratio of soil to additional compost will greatly boost available nutrition and water retention, while not sacrificing soil drainage.
- Available Sunlight - Onions are a full sun crop that base bulb production on their available photoperiod. If the critical photoperiod falls short or exceeds the requirements of your variety, onions may fail to produce bulbs altogether. Typically, short day varieties require 10-12 hour days to commence the bulbing process, whereas long day varieties will need 14-16 hours of daylight to do so.
Onion Seeds, Sets or Plants?
The first step for gardening onions in containers is to figure out how the process will start. To give you a basic idea of what each option entails, I've simply outlined each way in which onions can be started:
|Bag of Onion Sets. Normally priced at $5 for|
- Seeds - Onion seeds are the most inexpensive option for the gardener, but do require much more patience. For container gardeners, onion seeds must be started a few months before the average last frost for good bulb production. On the upside, gardeners will be able to choose the exact variety they wish to grow.
- Sets - Growing in containers, onion sets are the best way to start gardening. These small dormant bulbs were harvested before bulbing occurred in the previous season. These small onion bulbs generally set quicker and produce larger bulbs, something always desired by gardeners looking for maximum productivity!
- Plants - These ready to transplant onions are normally grown from seed and are sold in nurseries for inflated prices. Due to their unreasonable expense, it would really only make sense to purchase young onion plants if you got off to a late start on the season.
Container Gardening Onions -
For the sake of beginner gardeners out there, I'll be discussing how to grow onions using sets. Remaining relatively inexpensive in price, onion sets allow beginner gardeners the ability to bypass germaination and young seedling care. Here's a look at how to grow onions from sets in planters:
|This photo illustrates the varying sizes contained in bagged|
onion sets. Onions of 1/2" - 3/4"diameter are desired.
- Choose your container. When it comes down to onions, container depth is not neccessarily as important as the surface area of the soil. Since onion roots remain fairly shallow, a pot with a minimum depth of 6-10 inches should suffice. Wide shallow containers will offer more room to grow onions compared to containers that are narrow and deep.
- Four to six weeks before the average last frost in your area, fill the containers full with your potting soil mix and place outdoors in an area that receives full sun.
- From your set of onions, select bulbs that do not exceed 3/4" in diameter. Larger bulbs may bolt, while smaller bulbs may be underdeveloped by the end of the season.
- Dig shallow holes in the soil and plant each onion spaced 3-4 inches apart in rows spaced 10-12 inches apart. Alternately, if a large container is used, an all direction style of planting may be used. In this process, the onions are planted in all directions spaced 6-8 inches apart from each other. In either case, plant each bulb with the narrow end up and just deep enough so that a fine layer of soil covers them.
- Water the sets in well and within a couple of weeks, green shoots should emerge from the planted bulbs.
- Throughout the season, ensure that your onion plants are properly watered. On average, onions planted in containers will need to be watered at least once a week, with more waterings needed during hot dry spells. Avoid any tendency to over water by only watering onion plants when the top 1.5 inches of soil has become dry.
- Fertilizing will also need to be conducted on a regular basis throughout the early stages of onion development. From planting to a month before bulbing commences, onion plants should be fed once every couple weeks with a nitrogen heavy fertilizer. Homemade compost teas will more than easily do the trick, and can actually be fed at half strength weekly!
|Yellow Onions in Container. Just sprouting. Photo|
above and below taken 4/13/2012.
For now, I'm going to skip out on harvesting and storage of your homegrown onions. I'll come back to the topic as the time gets nearer to picking my own. Instead, I'd like to shift gears and show you the inter workings of my own container onions. Ha, it's not much, but it definitely gives you an idea of how it can be done!
- Container Size - 19" Long x 14" Wide x 7" Deep
- Variety of Onions - Yellow Rock. Medium sized, long day onion.
- Seed, Set, or Plant - Onions obtained in a set.
- Obtained From - Hungenberg Produce in Greeley, Colorado.
- Number of Onions Planted - 11
- Spacing - Six inches apart in all directions.
- Date Planted - 3/24/2012
Alright! So, that just about does it as far as how to care for onions in containers. I'll leave you with one more shot from the garden. Keep checking back to see the growth of my onions throughout the season. Thanks for reading!