When to Plant Onions in Indiana

Onions are classified as hardy vegetables because of their ability to grow in areas that experience harsh and hard-to-predict weather. However, determining when to plant onions in Indiana may be challenging because they are usually affected by extreme cold and need sufficient sunlight for bulbing.

Generally, onions are spring plants that produce well when planted in spring and harvested in the early summer. If you are a gardener in Indiana and wish to start onion planting, this article will cover more about onion gardening to help you yield a good onion harvest.


When is the best time to plant onions in Indiana?

when to plant onions in indiana

The specific weather predictions and conditions of your area are a key consideration when timing onions. Onions cannot survive when the soil temperature is below 50 degrees Fahrenheit, and as such, frost is considered a great enemy to the survival of onions in the soil.

In Indiana, onions should be planted a few weeks after the last frost fall. This is usually between mid-April and mid-May, basically, two weeks after the last fall. During this time of the year, the soil will be well-drained and relatively warm to facilitate the growth of many spring plants, including onions.

Planting onions too early when the soil still has frost particles is not advisable because the onion seedlings will automatically die. Similarly, planting onions late in spring means they will not get sufficient sunlight to facilitate bulbing, and you may harvest very small-sized onions or, worse, no onions unless you want green onions. Considering the local weather of your garden location will help you select your appropriate date that will favor the growth and maturity of onions.

You may also determine the planting time by considering the probable dates of the first fall. After identifying the date which the first frost fall is expected, you will need to subtract 70 days, and the date you come up with is the right date to start seeds indoors. This is because onions take approximately 70 days to mature from seeds to well-formed bulbs.

Overall, the best way to determine onion planting time in Indiana is by simply checking the weather patterns because nothing affects the maturity and growth of onions like bad weather.


How to plant onions

when to plant onions in indiana

First, select a site fully exposed to sunlight so that your onions are not overshadowed by anything nearby. Full sunlight is important for onions to form bulbs – the intensity of sunlight getting to the onions helps them produce many leaves, which with time aids the formation of large bulbs.

Dig a trench of about two inches deep and three inches wide, then fill it with almost one inch deep of manure or compost. You can do this a few days before planting the onion seedlings or sets. If you are a regular onion gardener, it is advisable to do crop rotation because it helps discourage the spread of diseases that easily affect onions.

When it comes to growing onions, you can either start with sets, seeds, or seedlings. For seeds, it is prudent to start them indoors if you wish to plant in spring. However, if you wish to plant in late autumn to harvest in early spring, you can directly plant seeds in the garden but make sure you protect them from the dangers of frost.

For onion sets, choose sets that are approximately ¾ inches in diameter, then plant them to the already prepared soil, spaced about 2 and 6 inches apart.

When you opt for transplants, select the larger seedlings and plant 4-5 inches apart and make the rows about 12-18 inches apart. Place the seedlings in the soil not so deep because high planting depth can lead to poor bulb development.


Caring for onions

when to plant onions in indiana

Onions are classified as leaf crops, even though they produce bulbs under the soil. Being a leaf crop, onions require sufficient sunlight and nutrients to produce large bulbs. Whether you are planting in early spring or late fall, the key issue is the soil drainage, fertility, and extent of being loose. If your soil is clay or hard, you will need to add compost to help boost the soil’s texture and improve its ability to hold moisture.

For bigger bulbs, try to fertilize the onions weekly with nitrogen-based fertilizers until the bulbs start forming. You will notice bulb formation when you see soil being raised and bulbs emerging on top of the soil. Do not put back the lifted soil to cover the bulbs; instead, add some light mulch to help retain moisture, aid air circulation, and suppress the growth of weeds.

Watering onions is not much necessary if you have already added mulch. However, you may add water once per week, or if it’s raining, the rainwater will be sufficient to prevent the onions from drying up too early before they mature.


When to plant onions in Indiana: Conclusion

Planting onions in Indiana may be a challenge to some gardeners, but once you master the art of timing, you will keep enjoying a good onion harvest. In this article, you can get help on how to do timing, when and how to plant, and caring for onions. Hopefully, you will find the article helpful.