How to Grow Pearl and Pickling Onions in the UK – Complete Guide

Learning how to grow pearl and pickling onions in the UK is a fantastic way to produce your own small, crisp onions for homemade pickles, casseroles and delicious savoury dishes. With the right variety, sensible seed sowing and close spacing, you can harvest lots of lovely little bulbs from a relatively small vegetable bed.

There’s something particularly satisfying about growing vegetables that you know you’re going to turn into a homemade preserve.

And if you’re a fan of traditional pickled onions, why not try growing the onions yourself?

Instead of buying a bag of pickling onions from the supermarket, you can start with a packet of seeds and produce a crop on your allotment.

Here at Gardening with Ben, I love growing vegetables that can be enjoyed long after the summer growing season has finished.

Onions are a fantastic example.

Ordinary yellow onions are brilliant for soups, pies and casseroles.

Red onions are lovely in chutneys and salads.

But smaller pickling onions have their own special place in the kitchen.

They’re ideal for making traditional pickled onions, and some varieties can also be used whole in stews or roasted vegetable dishes.

However, growing pickling onions is a little different from growing ordinary large cooking onions.

With standard onions, we’re often trying to produce big, healthy bulbs.

With pickling onions, we want the opposite.

We’re aiming for smaller onions that are reasonably uniform in size.

That means variety choice, sowing dates and plant spacing are particularly important.

In this complete UK growing guide, I’ll explain how to grow pearl and pickling onions from seed, including the popular ‘Paris Silverskin’ variety.

We’ll look at when to sow, how close to grow the seedlings, watering, feeding, harvesting and preparing your onions for the kitchen.

I’ll also explain how to grow them in raised beds and containers, along with common problems that can affect the crop.

So let’s get growing some fantastic little onions!

What Are Pearl and Pickling Onions?

Pearl onions and pickling onions are terms commonly used for small onions that can be eaten whole.

However, the names aren’t always interchangeable botanical classifications.

Pickling onions are often simply small bulbs of Allium cepa, the same species as ordinary bulb onions.

Some are produced from specific varieties selected for small, attractive bulbs.

Others are ordinary onions harvested small.

The term pearl onion is also used in different markets for certain small white onions, so it’s best to check the actual variety you’re buying rather than relying entirely on the common name.

Are Pearl Onions Different from Normal Onions?

They can be a different cultivar or type, but many belong to the ordinary bulb onion species.

Are Pickling Onions Always White?

No.

You can pickle white, yellow or red onions.

Do Pickling Onions Taste Different?

Flavour varies by variety and maturity.

Do You Need Special Seeds?

Not always, but specialist pickling varieties are particularly convenient.

Can You Grow Them on an Allotment?

Absolutely.

They’re a useful crop for smaller beds and succession growing.

Best Onion Varieties for Pickling in the UK

Choosing a suitable variety makes the growing process easier.

Paris Silverskin

‘Paris Silverskin’ is one of the best-known traditional pickling onion varieties in Britain.

It produces small, silvery-white bulbs with a crisp texture.

It’s particularly useful for making traditional pickled onions.

The variety is also suitable for harvesting young as a salad onion.

Seed suppliers describe it as relatively quick-growing and suitable for direct sowing in prepared outdoor soil.

Pompei

‘Pompei’ is another small white onion variety worth considering.

It’s known for producing rounded bulbs suitable for fresh use and pickling.

Onion de Paris

‘Onion de Paris’ produces small, somewhat flattened white bulbs that can be used for pickling or cooking.

Can You Pickle Red Onions?

Yes.

Red onion varieties can be harvested at a smaller size or sliced for pickling recipes.

However, traditional small whole pickled onions are often made using white or yellow varieties.

Which Variety Would I Recommend?

For beginners who want proper small pickling onions, I’d start with ‘Paris Silverskin’.

It’s widely available from UK seed suppliers and has a long history as a pickling variety.

When Should You Sow Pickling Onions in the UK?

The sowing period depends on your chosen variety.

For ‘Paris Silverskin’, UK seed suppliers commonly recommend sowing from spring into early summer.

Some allow early sowings under cover from February.

Outdoor sowings are often made between April and June, although local conditions matter.

Can You Sow in February?

Yes, if you’re starting suitable seeds under cover.

What About March?

Some gardeners can begin sowing outdoors when the soil is workable, depending on the variety and weather.

Is April a Good Month?

Absolutely.

April is a useful month for direct sowing.

Can You Sow in May?

Yes.

Can You Sow in June?

Many specialist pickling varieties can still be sown during early summer.

What About July?

Only where the variety and local season allow sufficient growing time.

My Recommendation

On a northern allotment, I’d make an initial sowing during April when the soil is suitable, then a smaller follow-up sowing if the seed packet permits.

Where Should You Grow Pickling Onions?

Choose a sunny position with fertile, well-drained soil.

Pickling onions don’t need a huge growing area, but they still require enough light and moisture to develop healthy bulbs.

Is Full Sun Best?

Yes.

Can They Grow in Partial Shade?

Some growth is possible, but bulb development may be reduced.

What About Heavy Clay Soil?

Clay can be suitable if drainage is good and the soil can be prepared into a reasonably fine seedbed.

Are Raised Beds Useful?

Absolutely.

Do Pickling Onions Need Rich Soil?

They benefit from adequate fertility, but excessive nitrogen isn’t necessary.

Can You Grow Them After Another Crop?

Yes, provided the sowing season allows enough time and you’re following sensible crop rotation.

How to Prepare a Seedbed for Pickling Onions

Because pickling onions are usually grown from seed, preparing the soil properly is important.

Begin by removing weeds.

Pay particular attention to persistent weeds that could compete with the small onion seedlings.

If necessary, improve the soil beforehand with mature compost.

Avoid recently applying large quantities of fresh manure.

Use a rake to create a relatively fine, firm surface.

Large clods can make it difficult to sow tiny seeds at a consistent depth.

Should You Water Before Sowing?

If the soil is dry, water the seed drill before sowing.

Do You Need Fertiliser?

Not automatically.

Should You Sow into Waterlogged Soil?

No.

Can You Grow Pickling Onions Without Digging?

Yes.

A prepared no-dig bed with a suitable surface layer of mature compost can work well.

Gardening with Ben Tip

Small seeds benefit from a neat seedbed. A few minutes spent preparing the soil can make germination and weeding much easier later.

How to Sow Pickling Onion Seeds – Step by Step

Direct sowing is one of the easiest methods.

Step 1: Choose Your Variety

Select a suitable pickling onion such as ‘Paris Silverskin’.

Step 2: Check the Seed Packet

Confirm the sowing season and recommended planting depth.

Step 3: Prepare the Bed

Remove weeds and level the soil.

Step 4: Mark the Rows

For ‘Paris Silverskin’, many suppliers recommend rows approximately 30 cm apart.

Step 5: Make a Shallow Drill

Aim for around 1–1.5 cm deep.

Step 6: Water the Drill if Necessary

Moisten dry soil before adding seeds.

Step 7: Sow the Seeds

Distribute them fairly evenly along the row.

You can sow more closely than you would for large storage onions.

Step 8: Cover Gently

Use a thin layer of fine soil.

Step 9: Firm the Surface

Gently firm to ensure seed-to-soil contact.

Step 10: Label the Row

Write down the variety and sowing date.

Step 11: Maintain Moisture

Avoid letting the seedbed dry out completely during germination.

Step 12: Watch for Seedlings

Small green onion shoots should begin appearing when conditions are suitable.

Step 13: Keep Weeds Under Control

Young onions compete poorly with weeds.

Step 14: Thin Only if Needed

Follow the variety’s recommendations and your preferred finished bulb size.

How Deep Should You Sow Pickling Onion Seeds?

For ‘Paris Silverskin’, several UK suppliers recommend a sowing depth of approximately 13–15 mm, or roughly 1.3–1.5 cm.

Other packets may specify slightly different depths.

Should You Bury the Seeds Deeply?

No.

What Happens if Seeds Are Too Deep?

Emergence may be delayed or reduced.

Can You Sow Too Shallowly?

Yes.

Seeds may dry out or be disturbed.

Is the Depth the Same in Raised Beds?

Generally, yes.

What About Containers?

Use the same seed packet guidance.

My Recommendation

Follow the instructions supplied with your chosen variety rather than guessing.

How Far Apart Should Pickling Onions Be?

This is one of the most important differences between pickling onions and ordinary maincrop onions.

With large cooking onions, you might leave 10–15 cm between individual plants.

For pickling onions, you usually want smaller bulbs.

That means closer spacing can be useful.

Some ‘Paris Silverskin’ instructions recommend sowing relatively densely without thinning.

Other seed suppliers recommend thinning or transplanting to approximately 2.5–7 cm between plants.

Does Close Spacing Produce Smaller Bulbs?

Generally, yes.

Can They Become Too Crowded?

Yes.

Severely crowded plants may struggle and produce very small bulbs.

Should You Thin the Seedlings?

Only as needed for your intended harvest size and the variety’s instructions.

What Size Bulbs Are Best?

Choose bulbs suitable for the particular recipe you intend to use.

Can You Grow Larger Pickling Onions?

Yes, by allowing more room and leaving the plants to grow longer.

My Recommendation

Try two short rows.

Leave one relatively closely sown and thin the other slightly.

When harvest time arrives, compare the bulb sizes.

Can You Grow Pickling Onions in Modules?

Yes.

Although direct sowing is convenient, module growing is another option.

It’s particularly useful when outdoor soil is cold, wet or difficult to prepare.

How Many Seeds Per Module?

For small onions, three or four seeds per module can work well.

Do You Separate Them?

Not when using the multi-sowing method.

Will They Produce Small Bulbs?

Generally, yes.

When Should You Transplant?

Once the seedlings are established and outdoor conditions are suitable.

Do They Need Hardening Off?

Yes, if raised in a protected environment.

Is Direct Sowing Better?

It avoids transplanting and can be particularly convenient for a dense crop of pickling onions.

Gardening with Ben Tip

If the allotment soil is still saturated during March, starting a few modules indoors is better than forcing tiny seeds into unsuitable ground.

Growing Pickling Onions in Raised Beds

Raised beds can be particularly useful for small onion crops.

They make it easier to prepare a fine seedbed and maintain consistent spacing.

Can You Sow Directly into a Raised Bed?

Absolutely.

Do You Need Wide Rows?

Use the variety’s recommendations or a grid suited to your growing method.

Can You Grow Them More Closely?

Yes, especially if your aim is to harvest small bulbs.

Does the Bed Need Good Drainage?

Yes.

Do Raised Beds Dry Out?

They can, particularly in warm weather.

What’s My Recommendation?

Dedicate a manageable section of a raised bed to pickling onions rather than scattering them between larger crops.

Growing Pickling Onions in Pots

You can grow small pickling onions in containers.

‘Paris Silverskin’ is sold as suitable for container cultivation by some UK suppliers.

Choose a container with drainage holes and enough compost for the plants to develop.

Do You Need a Huge Pot?

Not necessarily for small pickling onions, although a deeper, wider container provides a more stable growing environment.

Can You Direct Sow?

Yes.

How Closely Should You Sow?

Follow the variety’s instructions and thin if necessary.

Do Pots Need More Watering?

Often.

What Compost Is Suitable?

A good-quality peat-free growing compost with sufficient nutrients and drainage.

Can You Grow Them on a Patio?

Absolutely.

How Often Should You Water Pickling Onions?

Pickling onions need moisture for germination and healthy growth.

However, excessive watering can create problems.

During Germination

Keep the seedbed consistently moist enough for seeds to germinate.

During Seedling Growth

Water when the soil starts drying.

During Bulb Development

Avoid prolonged drought.

Can You Overwater?

Yes.

Waterlogged soil may damage the roots and bulbs.

Do They Need Water Every Day?

No.

What About Container Crops?

Check them more frequently during warm weather.

My Recommendation

Water according to soil conditions rather than following a fixed daily schedule.

Do Pickling Onions Need Fertiliser?

Pickling onions need adequate nutrients, but they’re not being grown to produce enormous bulbs.

In reasonably fertile soil, additional feeding may not be necessary.

Can You Use Garden Compost?

Yes, mature compost can help maintain soil fertility.

Should You Use Fresh Manure?

No, particularly immediately before sowing.

What About Chicken Manure Pellets?

Use only where appropriate and according to the product label.

Does Excess Nitrogen Matter?

Yes.

Too much nitrogen can encourage leafy growth at the expense of timely bulb maturity.

Do Container Onions Need Feeding?

They may, because nutrients in compost can become depleted.

My Recommendation

Start with healthy soil and don’t overcomplicate the feeding programme.

How Long Do Pickling Onions Take to Grow?

The growing time varies by variety, sowing date and conditions.

Some seed suppliers describe ‘Paris Silverskin’ as ready approximately 12–14 weeks after sowing.

Other guidance gives a wider range because onions may be harvested at different sizes.

Do Small Onions Grow Faster Than Large Onions?

They may be ready to harvest earlier because you’re not waiting for substantial bulb enlargement.

Can Weather Delay the Harvest?

Absolutely.

Does Close Spacing Affect Maturity?

It may influence bulb size and development.

Should You Harvest Everything Together?

Not necessarily.

You can lift selected bulbs as they reach the desired size.

Can You Leave Them Longer?

Yes, but they may become too large for whole pickling.

My Recommendation

Start checking the bulb size before the earliest expected harvest date.

When Should You Harvest Pickling Onions?

Pickling onions are normally harvested when the bulbs reach the size required for the intended recipe.

For spring-sown varieties, this often means harvesting from summer into early autumn.

How Big Should They Be?

Small enough to fit comfortably into your intended pickling jars and recipe.

Should You Wait for the Leaves to Die Back?

For fully mature bulbs, foliage will begin yellowing naturally.

However, pickling onions are often harvested young when they reach the desired size.

Can You Harvest Them While Green?

Yes.

Young onions can be used fresh.

How Do You Lift Them?

Carefully loosen the soil and lift the bulbs by hand.

Should You Wash Them Immediately?

If preparing them for food, remove soil and wash them appropriately.

Can You Harvest After Rain?

Yes, although wet onions need careful handling and prompt preparation or appropriate drying.

How to Prepare Homegrown Pickling Onions

After harvesting, you’ll need to prepare your crop according to the recipe you’re using.

Start by selecting sound, healthy bulbs.

Discard onions showing rot, mould or serious damage.

Remove soil and clean the onions.

Trim the roots and leaves as required by your chosen recipe.

Peel away the papery skins.

Can You Peel Lots of Small Onions Easily?

A brief blanch can help loosen skins, but only do this where the recipe calls for it.

Should You Use Bruised Bulbs?

Use healthy, undamaged onions for preserving.

Do You Need to Sort by Size?

It’s useful.

Similar-sized bulbs tend to prepare and pickle more consistently.

Can You Pickle Freshly Harvested Onions?

Yes, if you’re following a suitable tested recipe.

Can You Make Shelf-Stable Pickled Onions Without Following a Recipe?

Don’t improvise shelf-stable preservation.

Fresh onions are a low-acid food, so safe preserving requires a tested recipe with the correct vinegar acidity, proportions and processing or storage instructions.

My Recommendation

Grow the onions first, then choose a reliable tested pickling recipe that matches the bulb size and storage method you want.

Common Problems When Growing Pickling Onions

Small onions can suffer from many of the same problems as ordinary onion crops.

Poor Germination

Old seed, dry soil or unsuitable temperatures may be responsible.

Overcrowding

Extremely dense sowing can lead to tiny, weak bulbs.

Bulbs Becoming Too Large

You may have left them growing beyond your desired pickling size.

Yellow Leaves

Possible causes include natural maturity, drought, waterlogging and disease.

Onion White Rot

A serious soil-borne fungal disease that damages the roots and bulbs.

Onion Fly

Larvae may damage growing onions.

Downy Mildew

Can affect foliage during suitable humid conditions.

Weed Competition

Small seedlings compete poorly with weeds.

How Can You Reduce Problems?

Use fresh seed, prepare a fine seedbed, maintain suitable moisture, weed regularly and inspect plants throughout growth.

Pickling Onion Growing Calendar

Month	Jobs
January	Choose varieties and plan the crop
February	Start suitable seeds under cover
March	Prepare outdoor beds and make early sowings where appropriate
April	Direct sow pickling onion seeds
May	Continue sowing and weed existing rows
June	Make later suitable sowings and check earlier crops
July	Begin harvesting early sowings at pickling size
August	Continue harvesting and prepare onions for pickling
September	Finish suitable harvests and clear spent beds
October	Clean and store equipment; plan next season
November	Review which sowing dates performed best
December	Order fresh seed and plan preserving recipes

Ten Common Pickling Onion Growing Mistakes

1. Choosing a Variety Intended Only for Large Storage Bulbs

Pickling varieties are more convenient for producing small bulbs.

2. Sowing into Poorly Prepared Soil

Tiny seeds benefit from a fine seedbed.

3. Planting Too Deeply

Follow the variety’s recommended depth.

4. Letting the Soil Dry Out During Germination

Consistent moisture helps establishment.

5. Overcrowding Excessively

Close sowing is useful, but extreme crowding can weaken plants.

6. Thinning Every Crop to Standard Onion Spacing

You may end up with larger onions than you wanted.

7. Ignoring Weeds

Onions compete poorly with weeds.

8. Harvesting Too Late

Bulbs may become too large for the intended recipe.

9. Saving Damaged Bulbs for Pickling

Select healthy bulbs for food preservation.

10. Making Up a Shelf-Stable Pickling Method

Always follow a tested preservation recipe.

Frequently Asked Questions About Growing Pickling Onions

Can you grow pickling onions in the UK?

Yes. Specialist varieties such as ‘Paris Silverskin’ grow well in suitable UK conditions.

What is the best onion variety for pickling?

‘Paris Silverskin’ is a popular traditional choice.

Are pearl onions and pickling onions the same?

The terms overlap in everyday cooking, but they aren’t always identical botanical types.

When should you sow pickling onions?

Usually during spring and early summer, depending on variety.

Can you sow pickling onions in February?

Yes, under cover where recommended.

Can you direct sow in April?

Absolutely.

How deep should you sow pickling onion seeds?

Approximately 1–1.5 cm for many varieties, following the packet.

How far apart should pickling onions be planted?

Close spacing is useful. Some methods use roughly 2.5–7 cm between bulbs, while dense direct sowing may require little thinning.

Can you grow pickling onions in raised beds?

Yes.

Can you grow pickling onions in pots?

Yes, in suitable containers.

Do pickling onions need full sun?

Full sun is preferable.

Can they grow in clay soil?

Yes, provided drainage is suitable and the surface is workable.

How long do pickling onions take to grow?

Some varieties are ready around 12–14 weeks after sowing, though conditions and desired size affect timing.

Why are my pickling onions too big?

They may have been spaced too widely or harvested too late for your intended size.

Why are my pickling onions tiny?

They may be overcrowded or affected by poor growing conditions.

Can you pickle ordinary onions?

Yes, when properly prepared using a suitable tested recipe.

Do onions need to be completely mature before pickling?

Not always. Specialist varieties are often harvested at a young, small-bulb stage.

Can you eat Paris Silverskin onions fresh?

Yes, they’re also suitable for fresh salads and cooking.

Can you preserve freshly harvested onions?

Yes, following an appropriate tested recipe.

Do homegrown pickled onions need refrigeration?

That depends entirely on the tested preserving method. Refrigerator pickles must be kept chilled; shelf-stable products require a validated process.

Final Thoughts: Growing Your Own Onions for Pickling

For me, growing pickling onions is a fantastic way to make the most of a small part of your allotment.

You don’t need an enormous vegetable bed.

You don’t need expensive equipment.

And you don’t need to aim for the biggest onions possible.

In fact, producing lots of little bulbs is exactly what makes this crop so rewarding.

If you’re planning to make traditional pickled onions, I’d recommend starting with ‘Paris Silverskin’.

It’s a popular variety that’s been grown for many years and is particularly suitable for producing small, white onions.

Prepare a sunny, well-drained seedbed and sow during the recommended months.

Keep the soil appropriately moist during germination.

Then maintain the crop by removing weeds and checking the bulbs as they begin developing.

Remember that spacing affects size.

If you want smaller onions, closer planting can be useful.

And if you prefer slightly larger bulbs, allow more room.

One of the best things you can do is start checking the crop before it becomes fully mature.

That way, you can harvest the onions when they’re just the right size for your intended recipe.

Then comes the exciting part.

Turning your homegrown onions into something delicious in the kitchen!

Traditional pickled onions are a fantastic accompaniment to cheese, sandwiches and savoury meals.

And knowing that you’ve grown the onions yourself makes the result even more satisfying.

Just remember to follow a reliable tested preserving recipe, particularly if you’re preparing jars for storage rather than immediate refrigerated use.

So why not give pearl and pickling onions a go next season?

A packet of seed, a small prepared bed and a little patience could produce a lovely harvest.

Keep smiling, keep shining, keep gardening with Ben!