How to Grow Valencia Onions – A Beginner’s Guide

valencia onions plant growing in garden
Valencia onions, which are known botanically as Allium Cepa, are a type of vegetable that can easily be grown at home. Continue reading to learn the basics of growing valencia onions as well as common mistakes to avoid along the way.

Best Time to Plant Valencia Onions

This will depend largely on your local climate, but as a rule of thumb, begin to plant the valencia onion seeds Start indoors 8–10 weeks before last frost, plant out 4 weeks before frost. This is the best time to ensure that the seedlings survive the weather.

To check when valencia onions are most likely to thrive in your area, see the USDA Plant Hardiness Zone Map. If you live outside the US, do a quick search for ‘plant hardiness zone + [city]’.

How to Plant Valencia Onions the Right Way

There are a number of things to consider that will help you avoid some of the common mistakes of growing valencia onions in your home garden.

Often overlooked, your soil can have a huge impact on how well your valencia onions grow. Generally, your soil should be well drained sandy, loamy, or clay soils. Soil PH levels should be around 6.2 to 6.8.

roughly 3″ apart, keeping each row approximately 18″ apart. roughly 6″ apart in rows. The seeds should be sowed at a depth of about  .5″. For each plant, be sure to sow at least a few seeds to ensure that at least one of them will germinate.

Begin thinning your valencia onion seedlings  2-3 seeds per inch. thin to 6″ apart when plants are 6″ tall.

How Much Sunlight is Needed to Grow Valencia Onions

The amount of sunlight is another key to a successful harvest. Too much sunlight will dry out your valencia onions. Not enough sunlight will stunt your its growth or even kill it.

Ideally, your valencia onions should be getting full sun, which means as much sunlight as you can possibly give it, or at least 6 hours or more.

How Much to Water Valencia Onions

As you’ve figured by now, a lot can have an impact on how well your valencia onions do, and the amount of water is no different.

Ideally, the soil should be damp to touch; not soggy or bone dry. If the leaves on your valencia onions begin to change colors or start to look droopy, you need to adjust how much water you’re giving it.

Unfortunately, if you give it too much or too little water, you can kill it, so it’s best to just keep an eye on it and water as needed.

How Long Does it Take Valencia Onions to Germinate and Grow?

Now the fun part begins and you get to watch your valencia onions grow.

It takes approximately 10-12 days to germinate, and a total of 110-120 days from seed to harvest.

When to Harvest Valencia Onions

The best time to harvest your valencia onions is  when the bulbs are big and the tops begin to turn yellow and fall over.

Valencia onions can grow up to about 10-15 cm (4-6″) globes.

What Can Valencia Onions Be Used For?

Food Use:  Works well raw in salads or cooked.

Flavor Profile: Sweet and mild onion flavor with firm texture.

Can Valencia Onions Grow in Pots and Containers?

Yes, you will ideally need a 12″+ containerfor each plant. This can help control weeds and keep your plant from growing out of control.

It also gives you the flexibility to move your valencia onions around if you need to adjust sunlight or bring it indoors to avoid harsh weather conditions.

Are Valencia Onions Safe for Bees?

Yes, valencia onions are safe for bees.

According to, bees pollinate human food crops that make up about 90% of the world’s nutrition.

Given their importance in our ecosystem and food supply, I feel it is important to note that growing valencia onions is bee-friendly.

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