How To Grow An Onion From An Onion 12 Steps With Pictures

If you’re growing the onions outside, start your cuttings in early spring. For onions grown indoors, any time of the year is fine. You can use most onion varieties, including grocery store-bought onions, for growing more onions. This technique works best if you work with a fresh onion that has not yet gone bad.

If not discarding, you can use the rest of the onion for cooking or for compost if you prefer.

This will allow you to suspend your onion over water while it roots.

The bowl’s diameter should be less wide than the length of the toothpicks. To help the cutting grow faster, suspend the onion near a sunny window or place it outdoors.

You can also plant your onion bottom outside if your garden has well-draining soil. You can test to see if soil is well-draining by digging a 12 in (30 cm) hole in the soil and filling it with water. If the water drains in 5-15 minutes, the soil is well-draining. [2] X Research source

Depending on your preference, you can keep the onion cutting indoors or outdoors in sunny weather. If you plant the whole cut bottom as one piece, you may get more than one new onion but they will likely be crowded together and small. The number of plants a single onion can grow will vary from 1-6, the onion pictured above can be divided into two. To get multiple full size new onions from a single onion bottom, use a sharp knife to divide the onion bottom, leaving a portion of the roots on each section, as well as the leaves if it has started sprouting.

You can buy nitrogen fertilizer from most garden stores or nurseries. Check the label to determine how much fertilizer to spray into the soil.

Avoid spraying weed killers around the onion, as most herbicides can kill both weeds and garden plants. Check for small insects or other pests on your onion as well and, if you see any, spray the onion with a non-toxic, plant-friendly insect repellent.

When the bulb starts poking out of the soil, stop fertilizing the onion until you harvest it.

On average, it takes onions grown from cuttings about 90-120 days to grow a new bulb.