When to Plant Onions in Virginia? (Best Times for Success)

Depending on the Virginia growing zone (Virginia is divided into 5 zones), planting time for onions can vary from early March to mid-April.

The section below answers the question, when to plant onions in Virginia according to different zones, but as a standard rule, ensure a gap of two weeks between the planting date and frost date.

Best Time to Plant Onions in Virginia

1. Depending on the zone

Variation in geographic topography is the reason for different onion growing zones in Virginia.

The zone-wise breakup of onion planting time in Virginia is as follows

Apart from the zones, the planting times change depending on whether you are planting onions outdoors or indoors.

2. Planting Onions Indoors:

An economical way to plant onions is to first plant seeds indoors at least 70 days before the last frost date (refer table below). When you grow onions from seeds, simply placing them outside one fine day isn’t the right approach. Instead, start exposing them to sunlight approximately 5 weeks before the outdoor planting date.

Initially, expose plants to 1 hour of sunlight daily for 4 weeks, and after that, increase duration by 1 hour daily, till they are exposed to 8 hours of sunlight each day. After that you can place them outdoors or transplant them.

Such an approach increases disease fighting capacity of the onion plants.

3. Planting Onions Outdoors

The Minimum temperature at which onion seeds can germinate is 40°F. April temperatures in Virginia rarely fall below 51°F, making April a good month for planting onions.

Suitable outdoor planting times are roughly 2 weeks before the last frost date.

Disclaimer: The frost dates can vary by a couple of weeks. Best to refer to local weather to plant 2 weeks after the last frost date.

Once you have accustomed the onion plants in pots to outdoor weather, simply place them outdoors or transplant onion seedlings into the ground.

While planting the potted plants in the ground or even onion sets, follow the guidelines below:

1. Ensure onion plants are 6 inches apart. One row should be 1 foot away from the other. Onion planting spacing denser than this leads to less air circulation and higher probability of disease.
2. Ensure soil has all necessary nutrients, especially potassium and nitrogen.

Water the soil such that the top layer of the soil always remains moist. Onion plants have roots that go up to a depth of 2 feet. That is why they can only access moisture in the upper layer of the soil.

Tips for Successful Onions Planting in Virginia

1. Limit planting to a few varieties

Not every onion variety can be planted in Virginia. A few species which are suitable for Virginia include:

1. Red onions
2. Yellow Onions
3. Shallots
4. Sweet onions
5. Cipollini onions

It’s best to stick to these types to ensure the yield is high.

2. Plant the seed early

The best way to make it economically viable to grow onions is to plant the seeds first (indoors) and then plant them in the soil at the right stage.

The transition from indoors to outdoors is crucial since you cannot simply start keeping them outdoors on any random day. Refer to the section above to understand how to conduct this transition.

That means one needs to plant them twice and store them right.

However, when planting large quantities of onions, the resultant cost saving by buying onion seeds in bulk rather than onion bulbs makes sense.

One can also buy onion sets directly from the market and plant them on the dates mentioned above.

3. Mulch quickly

After planting onion sets outdoors, start mulching. Mulching helps onion sets in multiple ways:

1. Small roots of onions can only gain nutrients and moisture if they don’t have to compete with weeds. Mulching helps prevent weeds to a large extent, increasing the yield.
2. Mulching also reduces the evaporation rate of water, especially from the upper layer of soil, which reduces the need for watering.
3. Mulching also facilitates better air movement in the soil, which increases nitrogen, among other nutrients, in the soil.

With so many benefits, Mulching is necessary for onions rather than optional.

4. Ensure proper nitrogen content

Nitrogen is crucial for onion bulb growth. One cycle of onion plants needs up to 200 lbs of nitrogen per acre. Low nitrogen impacts the growth of onion plants resulting in small onions and stunted growth.

So, what’s the best way to increase soil’s nitrogen content?

A few effective ways to increase soil nitrogen include:

1. Planting soybean, clover, alfalfa, and peanuts, can increase nitrogen in the soil.
2. Add coffee grounds to the soil to increase nitrogen content and improve water drainage.

You can always use organic fertilizer to increase nitrogen and phosphorus in soil.

5. Harvest onions at the right time

The best time to harvest onions is when the bulb tops turn yellow or fall over. Simply pull them out of the soil and start curing after shaking off the soil still attached to the onions.

Frequently Asked Questions

Can you plant onions in the fall in Virginia?

Usually, daytime duration in Virginia during the fall ranges between 10 to 13 hours; therefore, only short day onion varieties can be planted during that time. In fact, fall is a great time to plant spring onions.

How late can you grow onions?

In fall, the last you can plant onions is Mid-December. In spring, the last you can plant onions is Mid-April. Anything later than that, and you risk onion plants getting impacted by frost.

When to harvest onions in Virginia?

Whether in Virginia or any other state, it is best to harvest onions when they are 6 to 8 inches above the soil. Additional indicators include:

1. Tops start turning yellow.
2. The bulb diameter ranges from 1 to 1.5 inches.

When to plant onions in Richmond, Virginia?

Richmond, Virginia, is in Zone 7; therefore, 11th March to 20th March is an excellent time to plant onion sets.

Conclusion

Instead of second-guessing When to plant onions in Virginia?, it is best to stick to the guide above, which provides a date according to the hardiness zones classified by the US Department of Agriculture. While sticking to these dates is always advisable, consider local weather to be doubly sure of no frost or extremely low temperatures.

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Know the best time to plant vegetables in Virginia:

• Sweet Potatoes
• Garlic
• Broccoli
• Pumpkins