Onion Plants

Onions are one of the most popular vegetables for growing in home gardens and are one of the first crops of spring. They can be stored over winter which makes a versatile crop. They are used in a huge range of dishes, both raw and cooked and are quite easy to grow.

  • Wide variety of delicious onions for sale
  • Perfect for pots and containers
  • Contact customer services six days a week, including bank holidays

Onion Plants
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Onion Plants FAQs

Take a look at some of the frequently asked questions we receive from those looking to buy Onion Plants in the UK. You can contact our Customer Service Team or browse our general FAQs for further advice.

When should I plant onion plants?

Onion plants are typically best planted in the early spring in the UK, around March or April. This timing allows the plants to establish themselves before the warmer months, leading to better bulb development. It's essential to avoid planting onion sets too early in the winter, as they may not survive the colder temperatures. Additionally, planting too late in the spring may result in smaller bulbs. By planting onion plants in the early spring, you can ensure a successful harvest later in the year.

How do you take care of an onion plant?

Taking care of onion plants involves providing consistent moisture, weeding regularly, fertilising with a balanced fertiliser, mulching to retain moisture and suppress weeds, thinning overcrowded plants for proper bulb development, and managing pests and diseases. Water onions thoroughly, providing about 1 inch of water per week, and avoid overwatering to prevent rot. Keep the area around the plants weed-free to reduce competition for nutrients and water. Apply a nitrogen-rich fertilizer every few weeks until bulbs begin to swell, and mulch with organic material to regulate soil temperature. Thin out overcrowded plants to promote airflow and reduce disease risk, and monitor for pests and diseases, taking appropriate action to control them. Harvest onions when the tops turn yellow and fall over, and allow them to dry before storing. With proper care, your onion plants will thrive and yield a bountiful harvest.

How long do onions take to grow?

Onions typically take about 3 to 4 months to reach maturity and be ready for harvest. However, this timeframe can vary depending on factors such as the onion variety, growing conditions, and planting method. Generally, onions planted from sets or transplants tend to mature more quickly, often taking around 3 months, while those grown from seeds may take slightly longer, up to 4 months or more. It's essential to monitor the growth of your onions and harvest them when the tops begin to turn yellow and fall over, indicating that they are ready for harvest.

Why Grow Onions?

Growing onions at home offers numerous benefits, including cost savings, superior freshness and flavor, and control over growing conditions. By cultivating your own onions, you can enjoy a versatile culinary ingredient for a wide range of dishes while tailoring the growing environment to optimize their growth and productivity. Additionally, homegrown onions provide access to a diverse selection of varieties, allowing for experimentation with different sizes, shapes, colors, and flavors. Tending to onion plants and harvesting a bountiful crop can be a rewarding experience, fostering a sense of satisfaction and connection to nature. Overall, growing onions offers the opportunity to enjoy fresh, flavourful produce, save money, and connect with the process of growing your own food.

Where can you grow Onions?

Onions can be grown in various areas of your garden, including garden beds, containers, raised beds, and even interplanted with other vegetables or herbs. Choose a sunny location with well-draining soil, and prepare the soil by incorporating organic matter such as compost. Garden beds offer flexibility in planting onions in rows or clusters, while containers are suitable for limited spaces like patios or balconies. Raised beds provide excellent drainage and soil aeration, and interplanting onions with other vegetables maximises space utilisation and pest deterrence. Additionally, cold frames or greenhouses extend the growing season for onions, allowing for earlier spring planting or later fall harvests. With proper care, onions can thrive and produce a bountiful harvest in various garden settings.

Why Buy Onion Plants from Marshalls?

  • Our customers are supported by a team of experts dedicated to providing valuable advice. You can also use our growing guides, backed by 70 years of experience, to get the best results from your onion plants.
  • You can contact us six days a week – including bank holidays – to discuss our products and services or to chat about all things gardening.
  • We pride ourselves on offering fast delivery on all orders, with any 'in stock' plants and seeds sent out within three working days. We're green-fingered in more ways than one, too, thanks to our fully recyclable packaging.
  • We won second place at the 2022 Great British Growing Awards for Best Online Retailer.
  • Thousands of five-star reviews on Feefo and a 100% satisfaction guarantee on all our products show that we're a company you can trust.