Onions and shallots are pretty much essential ingredients in every country around the world.
It is said you can’t make anything taste good without an onion in it!
Growing onions and shallots from sets is a popular method among gardeners due to its simplicity and reliability.
In this comprehensive guide, we will look at how to grow onions and shallots from sets.
An onion or shallot set is a small immature bulb grown from seed. These are planted to grow into one larger adult bulb. Make sure to select and prepare a sunny well drained site. Keep watered and harvest when the leaves flop over. Once cured they can be stored for several weeks.
What Is The Difference Between Onions and Shallots?
Before diving into the details of growing these two types of alliums, we need to understand the differences between onions and shallots and familiarise ourselves with some popular varieties.
Onions (Allium cepa):
- Onions are biennial plants belonging to the Allium genus, primarily cultivated for their edible bulbs.
- They come in various colours, sizes, and flavours, ranging from sweet to strong and pungent.
Shallots (Allium cepa var. aggregatum):
- Shallots are closely related to onions but have a milder, sweeter flavour and a more elongated shape.
- They grow in clusters of bulbs and are often used in gourmet cooking.
Popular Onion Varieties And Characteristics
- “Texas Sweet Onion” Large bulbs with golden-brown skin. Sweet, mild flavour. Ideal for grilling, frying, or eating raw. Moderate storage ability.
- “Stuttgarter” Yellow skin with white flesh. Large, round bulbs with a pungent flavour. Good yields and storage qualities. Versatile for culinary and pickling purposes.
- “Walla Walla” Large, globe-shaped bulbs with yellow-brown skin. Mild, sweet flavour. Excellent for fresh eating and salads. Not suitable for long-term storage.
- “Red Baron” Red skin with white flesh. Medium-sized bulbs with a sweet, mild flavour. Good storage qualities. Suitable for fresh use or cooking.
Popular Shallot Varieties And Characteristics
- “Yellow Moon” Golden-brown skin with pinkish-white flesh. Smaller, elongated cloves. Sweet, mild flavour, ideal for roasting and caramelizing. Excellent storage ability.
- “Zebrune” Reddish-brown skin with pinkish-white flesh. Medium-sized bulbs with a sweet, mild flavour. Good storage qualities. Versatile for various culinary applications.
- “French Red” Reddish-brown skin and pinkish-white flesh. Medium-sized cloves. Sweet and aromatic flavour. Ideal for enhancing the flavour of sauces, dressings, and vinaigrettes. Good storage qualities.
- “Dutch Yellow” Pale yellow skin. Pinkish-white flesh. Medium to large cloves. Mild and slightly sweet flavour. Excellent for pickling, roasting, and grilling. Moderate storage ability.
What Is An Onion Set?
An onion set is essentially a small, immature onion bulb that has been grown from seed and harvested before it reaches full maturity.
These sets are then sold to gardeners for planting purposes.
Using sets offers several advantages for home gardeners:
- Convenience: Sets are easy to plant and eliminate the need for starting onions from seeds indoors.
- Speed: The set will grow a mature onion much quicker than a seed will.
- Reduced risk of bolting: Onions grown from sets are less likely to bolt or prematurely produce flowers, ensuring a better harvest.
- Wider variety: Sets are available in various onion and shallot varieties, allowing gardeners to experiment with different flavours and colours.
Growing Onions And Shallots From Sets
Selecting And Preparing The Site
- Choose a sunny location with well-drained soil for planting onions and shallots.
- Avoid areas prone to waterlogging, as this can lead to rot.
- Prepare the soil by removing any weeds and incorporating organic matter such as compost or well-rotted manure to improve fertility and soil structure.
- Ensure the soil pH is between 6.0 and 7.5, as onions prefer slightly acidic to neutral conditions.
Planting Onion Or Shallot Sets
- Firstly examine your sets and discard any that look mouldy or feel hollow.
- Plant onion sets in early spring, as soon as the soil can be worked.
- For shallots, planting can also be done in autumn for overwintering.
- Space the sets approximately 4-6 inches apart in rows spaced 12-18 inches apart.
- Plant them with the pointed end facing upwards and bury them just below the soil surface, leaving the tip exposed.
- Water the sets thoroughly after planting to settle the soil around them.
Caring For Onions And Shallots
- Water onions and shallots regularly, especially during dry periods, to ensure consistent moisture levels. However, avoid overwatering, as this can lead to rotting.
- Mulch around the plants to suppress weeds, retain moisture, and regulate soil temperature.
- Fertilise onions and shallots sparingly, as excessive nitrogen can promote lush foliage growth at the expense of bulb development.
- A balanced fertiliser or one specifically formulated for onions can be applied according to package instructions.
- Monitor for pests and diseases, such as onion thrips, onion maggots, and fungal diseases like onion white rot.
- Remove any affected plants promptly and consider using organic pest control methods if necessary.
Harvesting and Storage
- Onions and shallots are ready for harvest when the foliage turns yellow and begins to flop over.
- Lift them carefully from the soil and allow them to dry in a warm, well-ventilated area for several weeks.
- Once fully cured, you can trim the foliage and roots, leaving a short stub. Or you can leave the leaves long and use them to hang the onions up.
- Store onions and shallots in a cool, dry place with good air circulation.
- Properly cured and stored bulbs can last several months, providing a steady supply for cooking use.
Common Growing Problems and Solutions
Bolting
- Bolting, which means premature flowering, can occur in response to stress factors such as temperature fluctuations or inadequate watering.
- This is bad because all of the plant’s energy goes to the flower rather than the bulb, causing smaller and tougher bulbs.
- Choose bolt-resistant varieties and ensure consistent moisture levels throughout the growing season.
- Plant onions and shallots at the appropriate time for your region to minimise exposure to temperature extremes.
Onion White Rot
- Onion white rot is a fungal disease that causes the roots and basal plates of affected plants to rot, leading to stunted growth and yellowing leaves.
- Practice crop rotation, avoid planting onions and shallots in soil where alliums have been grown in the past three years.
- Improve soil drainage and sanitation practices to reduce the spread of fungal spores.
Onion Maggots
- Onion maggots are the larvae of the onion fly “Delia antiqua” which tunnel into onion bulbs, causing rot and reducing yields.
- Use floating row covers to prevent adult flies from laying eggs on onion plants.
- Remove and destroy any infested bulbs promptly.
- Consider applying beneficial nematodes to the soil to control onion maggot populations.
Frequently Asked Questions
Question 1: “Can I grow onions or shallots from store-bought ones that have started to sprout?”
- While it is possible to grow onions or shallots from store-bought bulbs, the success rate may vary.
- Store-bought onions are often treated with chemicals to stop them sprouting, which can affect their ability to grow.
- Additionally, some varieties sold in grocery stores may not be well-suited for growing in home gardens.
- For best results, it is best to purchase onion sets or shallot sets from reputable garden centres or nurseries.
- These sets are specifically grown and selected for planting purposes, ensuring higher germination rates and healthier plants.
- Alternatively, if you choose to use store-bought onions, look for organic varieties that have not been treated with chemicals to inhibit sprouting.
Question 2: “Can I grow onions and shallots in containers?”
- Yes, you can grow shallots in containers, which is perfect for people with smaller plots or yards.
- Container gardening offers several advantages for growing shallots, including better control over soil quality, moisture levels, and pest management.
- To grow shallots in containers, choose large, deep containers with drainage holes to prevent waterlogging.
- Fill the containers with a well-draining, nutrient-rich potting mix, leaving enough space at the top for planting the shallot sets.
- Plant shallot sets in the containers, spacing them evenly and covering them with a few inches of soil.
- Water the containers regularly to keep the soil evenly moist but not waterlogged.
- Fertilize the plants with a balanced fertiliser or organic compost every few weeks to promote healthy growth and higher yields.
- Container-grown shallots require minimal maintenance and can be placed in a sunny location on a patio or balcony.
Question 3: “When is the best time to plant onion and shallot sets?”
- The best time to plant onion and shallot sets depends on your local climate and growing conditions.
- In general, onion and shallot sets are planted in early spring, as soon as the soil can be worked and temperatures begin to warm up.
- For regions with mild winters, you can plant onion and shallot sets in the autumn for overwintering, which allows them to establish roots and produce an early harvest the following spring.
- In colder climates, it is best to plant onion and shallot sets in early spring to avoid frost damage to the young plants.
Final Thoughts
Growing onions and shallots from sets is not too difficult and a good one for those gardening in containers.
By selecting the right varieties, providing proper care, and addressing common growing challenges, gardeners can enjoy a successful onion and shallot harvest year after year.
Another great vegetable to try growing is potatoes – check out our article here.