How to Grow Onion Seeds: A Comprehensive Guide

Growing your own onions from seeds can be a rewarding experience as it gives you full control over the types and varieties you grow. In this guide, we’ll break down the steps to successful onion seed cultivation, from selection and planting to harvesting and storage.

1. Selecting Your Onion Seeds

Before you can start growing your onions, you’ll need to pick the right seeds. You’ll find a wide selection of options, from white, red, or yellow onions to sweet or tangy varieties, each with its own unique growing needs. Look for seeds that are suitable for your growing region and consider what you’ll be using the onions for – pickling, roasting, grilling, or fresh in salads.

Additionally, consider the storage capabilities of the different varieties. Some, like red and white onions, are great for short term use, while others, like yellow onions, are known for their long storage capabilities.

2. Planting the Seeds

Once you chosen your seeds, it’s time to plant. Onion seeds can be planted indoors in a seed tray filled with compost. The seeds should be sown thinly, covering them lightly with compost. Place the seed tray in a well-lit, warm position, ideally at a temperature of around 10-15°C.

Ensure to keep the compost moist after sowing. Germination can take anywhere between 7-21 days but maintaining the right temperature and moisture levels can significantly improve the germination rate.

3. Caring for Your Growing Onions

Once your seeds have sprouted, they’ll need plenty of light and the right nutrients to grow into strong, healthy plants. Feed them weekly with a general-purpose fertilizer, making sure to follow the instructions on the label.

Onions prefer a location that gets at least 6-7 hours of direct sunlight each day. If you’re growing the onions indoors, consider using a grow light to ensure they get the light they need.

4. Transplanting Your Onions Outdoors

Once your onions have grown to about 3-4 inches tall, they’re ready to be transplanted to your garden or an outdoor container. Carefully remove the seedlings from your seed tray and plant them in well-drained soil. The bulbs should be planted about 1 inch deep and 4-6 inches apart to give them enough room to grow.

Remember to water the onions regularly, but avoid over-watering. Too much water can lead to bulb rot. You’ll also want to keep your onion patch free of weeds, which can compete with your plants for key nutrients.

5. Harvesting and Storing Your Onions

You can start to harvest your onions once the bulbs are big enough to use. Do not wait for the leaves to yellow or flatten as is commonly advised. Harvested onions should be placed somewhere dry and airy to encourage the skin to harden.

Once cured, onions should be stored in a cool, dry place. It’s a good idea to check your onions periodically and remove any that are starting to spoil, to prevent it from affecting the others.

__Frequently Asked Questions__

  • Q: When should I start onion seeds indoors?
    A: Onion seeds should be started indoors 8 to 10 weeks before the last expected frost in your area. This allows the plants to grow large enough to be transplanted outdoors.
  • Q: How long does it take for onion seeds to grow?
    A: From sowing to harvest, onion seeds usually take around 20 to 30 weeks to grow, depending on the variety and growing conditions.
  • Q: Can I save my own onion seeds for planting?
    A: Yes, you can! Just let a few of your healthiest plants produce flowers and seeds, then collect and dry them for future planting. However, remember that onion seeds don’t store very well and their germination rates drop significantly after the first year.