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Can You Plant Moldy Onion Sets

Onions are a super fun thing to grow in your garden that will also hold space in your garden beds during the winter. They are easy to grow, plus it is exciting to have and save your homegrown onion onions. There are a couple of ways to grow onions, the most common way is from onion sets. But, can you plant moldy onion sets?

Yes, you can plant moldy onion sets.

Onions sets or onion bulbs are usually how people grow their onions. If these sets are not kept in the right conditions, dry and dark, then mold will likely begin to grow around or on the onion set. However, this shouldn’t stop you from planting your onion set! It can still be done and not wasted. 

Below, we have gone over what causes moldy onion sets, how to plant them, and more! Keep reading. 

What Are Onion Sets?

First, to understand planting onions, you must understand what an onion set is. You can either plant onions from onion seeds or onion sets. Onion sets are onion bulbs that were picked prematurely. Originally, they were grown from seed the year before, but now they will be used as bulbs to plant onions the following year.

They are much smaller than a regular onion, around the size of a nickel. Though you may be smaller than if you were growing from seed, it is much easier to grow onions from onion sets; they are usually easier to buy and find. 

What Causes Moldy Onion Sets

There is only one thing that causes moldy onion sets, and that is- moisture. Onion bulbs must be kept in dry, dark conditions since they are extremely susceptible to mold. Any moisture that gets inside the onion bulb and sits for even a short time will cause mold. 

How To Plant Moldy Onion Sets

If you notice mold forming on your onion set, you’ll want to check it before planting it. Check to make sure you can still feel the bulb inside.

Sometimes, mold will cause the bulb to shrivel up and become dust, which will not grow anything at that point. If you can still feel that it is firm on the inside, then you are good to go! If it is much, then throw it away. 

Once determined plantable, plant it as you would a normal onion set. 

Step One

You can plant your onion sets in the early spring, as soon as the ground is ready to be worked in (not frozen). Or you can plant your onion sets in the late fall, and the set will remain dormant during the winter. 

Make sure you plant your onion sets in good soil with rich fertilizer or compost. Onions are heavy feeders and love nitrogen. You also want to make sure your soil is loamy and well-draining. 

Step Two

Plant your onion sets 2 to 6 inches apart and about 1 inch deep in the soil. Make sure they are pointing upwards with the pointed end facing up; this is where the sprout will form. Keeping onion sets not too deep in the ground is important as this affects their yield

Tips For Planting Onions 

Here are some insider gardener onion planting tips. 

  • Plant them closer together to harvest them prematurely as scallions
  • Soaking onion sets before planting them with help them sprout earlier
  • Most varieties of beans and peas should not be planted near onions
  • A layer of mulch around onion plants will help retain moisture 

Final Thoughts 

Onion sets are the easiest way to grow onions. While you don’t want your onion sets to get moldy, it isn’t that big of a problem, and you will be able to plant your onion sets as you normally would.

The mold will likely not affect your yield, and they should grow just fine. You are good to go if you squeeze the moldy onion set and can still feel the bulb inside. Happy gardening!