How to Plant and Grow Onion Plants

onions
Photo by Thomas Martinsen

Onions are some of the easiest vegetables to grow for novice gardeners. They have also a large range of health benefits. These plants can survive dry conditions and recover from them nicely, so they’re suitable for growing in both dry and humid environments. Despite their versatility, onion plants still need care and cultivating in order to grow to a healthy size and develop an appealing taste.

Preparing the soil for onion plants

Generally, it’s best to start onion plants as indoor seedlings by sowing the seeds into small containers and then transplanting them later. Onions need well-watered fertile soil, so make sure that your gardening site receives plenty of water either from rain or from your gardening hose. Loosen the planting soil and add manure to fertilize the ground for seeds. Test the pH level of your soil to make sure it is within a range of 6.0 and 6.8.

How to plant onion plants

If you intend to grow your onion plants inside first, sow the seeds about six weeks before you want to transplant them. You can move them outside four weeks before the final frost of spring. When you’re ready to transplant the seedlings, give them a space of five inches on all sides and set no more than one-third of the bulb into the ground. If you submerge the entire onion bulb into the soil, the plant may be overwhelmed and unable to grow to its full size.

Caring for your onion plants

To make sure that your onion plants grow well, water them steadily throughout the growing season. If your climate is arid, give them a bit more water than usual to keep them from drying out. Add a layer of mulch to the soil, which will help the ground retain moisture. As the plants grow, the bulbs will begin to peek through the soil. Resist the temptation to cover them soil again. They need the sunlight to continue developing.

How to harvest onion plants

To know when it’s time to harvest your onions, watch the tops of the stalks. When they start falling over and changing to a yellow color, the bulbs are ready for harvesting. Unlike leafy vegetables, onion plants must be grown from scratch each year. This means that you can simply pull the entire bulb out of the ground to harvest it. Shake the soil off the plant and then lay it out to dry in a place that gets plenty of circulating air. Cut the top stalks off after about a week and then keep the bulbs in the refrigerator until ready to eat.