Walla Walla onions are a federally protected crop that are grown in the Walla Walla Valley and North Eastern Oregon and only onions grown in these areas can be officially called Walla Walla onions.
Although this may be the official case, it is possible to grow this sweet tasting onion, yourself, in other areas and to purchase the seeds to do so.
If you are growing Walla Walla onions then you need to plant them in a moist and even soil that was well prepared during the winter. Plant them in the Spring in a sunny location. They can be grown from sets or young plants that are purchased bare rooted.
How long do Walla Walla onions take to grow?
They take 80-115 days to mature.
During the growing season, you need to keep your onions well watered and in an area that is shaded from the hottest of sunlight.
This will help them develop their sweetness and avoid the pungent taste that many people don’t enjoy with onions.
Growing Walla Walla onions from seed
If you decide to grow your onions from seeds then you will need to allow for a much longer growing season.
Most gardeners that grow from seed start the seeds indoors or in a greenhouse in the late winter to give the plants as much opportunity as possible to mature later in the year.
The seeds should be sown thinly onto the surface of dampened compost and covered before being placed in a warm place to germinate.
Once the seedlings emerge they should be placed in a light area before being planted up to larger containers.
Before planting the young plants out you should ensure that they have been accustomed to outdoors temperatures and plant out after any potential frosts have ended.
Growing Walla Walla onions from sets
Onion sets are small onions that have been temporarily halted in their growth and are often the best way to grow onions.
In early spring, when frosts have ended, simply push the onion sets into the ground, root down, until the tip of the onion is just visible.
Place the sets an inch apart.
Inspect daily and make sure that they don’t become ‘loose’ in the soil as they can push themselves out – just push any loose ones back in.
Sets help to reduce the growing season – ideal for areas that have short summers and are normally a very reliable way of growing onions.
How to plant Walla Walla onion starts
In some areas you will be able to buy Walla Walla onion ‘starts’.
These are young plants, that are pencil thickness which are often provided ‘bare rooted’ ie: not potted.
You should get them planted as soon as possible after purchase and give them a good water.
Plant them an inch apart in a good, sunlit area for best results.
How often do you water Walla Walla onions?
To get the best growth from your onions you will need to make sure that they have plenty of water.
In hot, dry spells you will need to irrigate more often, during the evening after the heat of the day is best.
Aim to try and get the top few inches of soil wet without creating a boggy or muddy mess.
If your onions look as though they are drying out or the soil is becoming tough then water more often.
What is the best fertilizer for Walla Walla onions?
During the growing season, water your Walla Walla onions with an all purpose fertilizer that has been diluted to half strength or less.
You can also add compost to your soil and this will help to keep it healthy and add nutrients for your onion crops.
You need to make sure that you don’t over feed the plants as this could result in an onion with a bitter taste.
Are Walla Walla onions affected by pests?
Walla Walla onions can be affected by a number of pests including thrips and onion maggots.
To prevent these pests from attacking your crops, water them in the evening and make sure that you weed around the plants on a regular basis.
Can Walla Walla onions be grown in pots?
Yes, you can grow this onion in pots and one of the great advantages of this is that you can move the pots around to get maximum sunlight – you can also take them indoors to extend the growing season.
Onions grown in pots will need frequent attention to make sure that they don’t dry out.
You should use a good quality compost or potting soil for pot grown onions.
How do you harvest Walla Walla onions?
You should have your onion harvested when the tops of the leaves begin to show signs of yellowing and collapse. This means that they are ready for cutting and pickling, but they can also be eaten whole if you prefer not to cut them up.
When harvesting these onions, you may want to wear gloves as the juice can be a bit of an irritant to your skin.
What do Walla Walla onions taste like?
These sweet onions are often compared to Vidalia onions in that they have a mild and sometimes caramel-like flavor, but they are not usually very large.
They can range anywhere from one to two inches in diameter.
Can you eat the green tops of Walla Walla onions?
Yes, they are great in salads and side dishes.
How long do they keep?
Walla Walla onions will last for a month or two if stored under ideal conditions, but you may want to eat them faster than that as you are sure to fall in love with the taste!
They can be frozen for longer term storage and should also be used within several days of being picked if you don’t want them to lose their sweetness.
Walla Walla onions are a popular variety because of their distinct taste and mild flavor.
They can be used in the kitchen but also have health benefits and can help prevent many diseases that are related to your cardiovascular system.
They are very easy to grow and, once you know how, they will be one of the first things that you want to plant in your garden.