When to Plant Onions in Missouri

Onions are versatile vegetables that can be used in many cooking recipes. Most of the world’s greatest meals start with pieces of sliced onions. Having onions in your garden is one of the greatest farming decisions you can make.

If you are a resident of Missouri, you already know that the weather may not be easily predictable, and farming can be quite challenging. If you plan to plant onions, keep in mind that the process won’t be easy. You will need to plant at the right time, choose appropriate soils and maintain your vegetable plot. This article will cover when to plant onions in Missouri and the tips to help you get a good harvest.

When is the right time to plant onions in Missouri?

When to plant onions in Missouri

Even though different onion species do well in Missouri, you need to be sensitive to the timing. You should plant onion two weeks after the last frost. At this time, the soil is cool enough to support the bulbing of onions.

In most cases, this time is usually in the last weeks of March or early weeks of April. However, the years are generally not the same. For some years, the last frost comes later, while it happens much earlier in other years. To be sure, always be very diligent in identifying when the last frost falls and start preparing to plant onions outside.

If frost comes after you have planted your onions, they may end up rotting while in the soil. To be safe, always plant the onions in pots that you can easily carry to the house if frost starts falling again. Similarly, if you are not able to use portable pots, you can still plant them on the ground but remember to cover them in burlap in case frost comes again.

When doing your timing, also avoid planting onions too late. Late planting will lead to low or no harvest of onions at all. Try as much as possible to plant within the right time, not too early and not too late. This way, you will harvest many onions that are of good size.

When to start onion seeds indoors

When to plant onions in Missouri

First, you will need to check your locality’s weather predictions from the previous years. By doing so, you will be able to identify the average last frost date of the previous years and gauge when the next frost fall will end.

Onions take at least 60 to 70 days, depending on their type, to grow from seeds indoors before being transplanted outside in a larger garden. To get a specific date when you need to plant onion seeds indoors, you should gauge the last date of frost fall and then subtract 70 days. As you do it, pay close attention to the weather patterns.

The best way to transplant your onion seedlings is by bringing them outside for an hour to introduce them to sunlight each day and increase the time gradually until it gets to eight hours. By doing so, you will be hardening your onions so that they increase their ability to fight diseases, insects, droughts, and wet conditions.

Considerations to make before planting onions in Missouri

When to plant onions in Missouri

Site selection

Always select a site with well-drained and fertile soils in an area well exposed to sunlight.

Soil preparation

Till the soil when dry, so it does not stick to the tools. Before transplanting, make sure you dig the soil at least 8-10 inches deep. Make sure the soil is smooth, with no rocks or trash.


You can plant onions from seeds, small bulbs, or transplants. Ensure the weather is cool because onions do better in a cool and low-temperature region.


Remove all weeds from your onion fear because they compete with the onions for nutrients. You can use your hands to pull out the weeds or use a hoe, but try not to dig too deep because you can up cutting the onion bulbs. In case of insect or pest infestation on the onions, you should use the appropriate pesticides to clear them away.


If you wish to harvest dry bulbs, you will want until the onions mature enough. This is when the main onion stem begins to weaken and fall off. You can now harvest and leave them in the garden for two days before removing the tops. Put the onions in baskets, so they continue drying.

When to plant onions in Missouri: Conclusion

Planting onions in Missouri can be a hard task, but you can still get a good harvest from onions if you do proper timing. If you are planning to plant onions in Missouri and you don’t know when to start planting them, this article can be of great help.