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How to Care for the Pregnant Onion (Ornithogalum Longibracteatum) – Onion Plant Flower

Long before I came across the pregnant onion (Ornithogalum Longibracteatum), I blandly went with the literal notion that it was just another typical onion variety. But after in-depth debunking, I learned that the pregnant onion is a bulb-like flowering plant that belongs to the lily (Liliaceae) plant family.

It’s native to South Africa, but surprisingly, it thrives in a couple of locations across the US that have the same outdoor conditions, ideally around the southern parts of California.

Pregnant onion

As you may know, the Lily family consists of over 4000 species, and a significant part of it is made of perennials that make fantastic houseplants. And in contrast to most houseplants, the South African born variety only needs the basic soil requirementswhich we’ll discuss extensively in this article.

Just to give you a snippet, the ultimate goal of this guide is to help you maintain ravishing foliage for your pregnant onion throughout the year.

More About The Pregnant Onion

If you don’t have so much context about this plant, you’re probably wondering why people call it the “ pregnant onion’’ while it’s not from the onion family. It’s simply because the plant appears to have several bulblets that sprout on the outer shell of the main plant bulb.

These baby bulbs don’t detach themselves from the mother plant but form beneath the skin of the main bulb. You can pluck a leaf from this area and replant it. We’ll discuss in detail how to propagate your pregnant onion, just so you know.

This plant also goes by two names:

  1. The “false sea onion” or the
  2. Unusual onion.”

It borrows these two names from its unforeseen botanical tendency to produce new bulbs on the sides beneath its base point. So multiplying the number of pregnant onions in your garden or windowsill won’t be a hard thing to do.

Taking Care of The Pregnant Onion

How Tall Does The Pregnant Onion Grow?

Taking proper care of your unusual onion to make the plant reach its optimal height, ultimately requires a few extra hacks. Usually, the pregnant onion grows to an optimal height of about 4” inches. Within time, the main bulb sprouts a few sturdy leaves that grow to about 2’ feet tall under bare bone growing conditions.

And if you expose your pregnant onion to even more suitable conditions, it yields much faster and grows to up to five feet in height. Since this plant’s metabolism doesn’t tune it to reach extreme heights, it’s such a perfect indoor plant that would ideally fit in a moderate-sized growing medium.

Like any other plant, the pregnant onion has a few distinct growth requirements you’ll need to catch up to speed with. First, you want to know if your location has the most conducive zone for it to thrive in.

With a USDA hardiness zone of between 4 – 10, this suggests that you can grow the pregnant onion outdoors all year long. But then, if you’re looking to have more radiant foliage, it’s far much better to put the growing medium indoors under warmer temperatures.

Flowering & Scent

The pregnant onion is one of the few perennial plants that bloom on certain seasons. Once your plant begins to have a fleshy growth, it yields a few tiny flowers both in the spring and summer seasons. It produces greenish-white flowers on the top part of mature stemsthat have a natural fragrance and create a scenic aesthetic for your indoor space.

To maximize its flowering potential, you want to protect your plant from harsh temperatures and pest attacks using a few steps which we’ll talk about later in this guide.

Soil & Transplanting

Using the right potting soil goes a long way to keep your plant sturdy and healthy. Luckily, you don’t need to be a gardening nerd to figure out how to match all the soil and transplanting conditions in the exact order which suits the growth of your pregnant onion.

Far from many other feeble perennials, this is an easy-to-grow pot plant that strikingly grows ‘pregnant’ at a tender age without the help of the mother bulb or potent fertilizers.

Of course, you’ll need to use well-drained soil that’s rich in essentials macronutrients such as nitrogen, phosphorus, and potassiumto make your pregnant onion grow large and lush. You can choose to go a little extra and mix your potting soil with some bits of perlite to lighten the soil for water intake and allow easy airflow.

If your plant overgrows the pot, that calls for a transplanting exercise which you’ll need to do with great care. The most ideal season for repotting is around spring since it’s exactly when baby bulbs try to separate themselves from the mother bulbs.

Light & Temperature

Being a subtropical plant, the pregnant onion is ever yearning for more sunlight. Roughly, you need to expose it to about 4-5 hours of sunlight every day. Depending on the season, you want to rotate your plant accordingly especially if you’re looking to put the growing medium outdoors.

During spring and fall, your plant should have a cocktail of both full and partial sun exposure. In summer, on the other hand, you need to regulate the level of contact with the UV rays.

If you’re planning to grow your plant indoors, placing the pot on a window with direct sunlight throughout the day, ideally one that faces south, would be a perfect spot to optimize access to natural light.

You also want to make a few temperature adjustments during winter, mostly if you’re growing your pregnant onion outdoors since it tends to diminish its foliage and overall wellbeing if placed under freezing conditions.

The pregnant onion requires a typical room temperature of about 22 °C, or anything slightly above that, to develop into a mature plant.

Watering & Fertilizer

The pregnant onion needs enough watering, but not too much of it. If your plant is soaked in water for so many days, this would damage the whole root system and slack off the rate of nutrients intake. Your plant only needs a few doses of water during winter. Also, don’t use fertilizer around this period.

It’s ideal to use liquid fertilizer because it dissolves much quicker. The best seasons to fertilize your plant is during spring, summer, or fall.

Grooming Tips

Although the pregnant onion is made of a very fine texture, it isn’t much of a feeble plant. What’s incredible about this variety is it remains intact and keeps on blooming even when you neglect it for a couple of days. So you won’t need to run so many maintenance errands to make its foliage ever-glowing.

As the plant begins to mature, the older layers will get weak and dry. You can peel them off to sustain its radiant appearance.

How To Propagate Your Pregnant Onion

Even if gardening isn’t your lingo, propagating the pregnant onion is one of the most engaging exercises you’ll enjoy doing. It’s essential to propagate your plant, especially when it hits its maturity stages. Propagating your pregnant onion is the only way to replant a more vibrant breed of bulblets in your garden, and keep the new blossoms from overrunning your growing medium.

To get started;

  1. Use a sharp knife to carefully remove the baby bulbs from the mother bulb without causing any irreparable damage to the whole plant.
  2. The next basic step would be to prepare the potting soil. Like we mentioned before, it’s ideal to use rich soil with a texture that allows easy drainage to avoid the rotting of roots. If you want to grow the new bulbs as houseplants, you could use general-purpose potting soil since its handy for drainage.
  3. Allow the soil to dry up before watering your baby bulbs afresh. Overwatering would damage the whole propagating process since it ruins the root development.
  4. Same as the mother bulbs, your new babies need similar growing conditions and a growing medium made of a sizeable part of sandy soil to enhance the rate of water drainage.
  5. You also want to give the bulblets full exposure to the sunlight, more particularly if you’re growing them as houseplants.
  6. As it grows, pluck off the old and dead leaves right from the bottom part of the onion.

Best Practices For The Control of Pests & Diseases

Most homeowners choose to plant the pregnant onion over other varieties since it’s not prone to the common hostile pests and diseases that diminish the general wellbeing of houseplants. You’ll however need to observe a few routine steps to keep your onion from any possible pest attacks.

First, it’s crucial to inspect the leaves for any damage every so often because that’s the hiding spot for many pests. You’re likely to encounter mealybugs mostly during late summer and autumn.

As a remedy, dip a cotton swab in a solution made of 70% isopropyl alcohol and use it to clear the bugs from the leaves if the attack is mild. When the infestation is too grievous, spray your plants with a more potent insecticide, to suppress the life cycle of the bugs.

To get a hold of the right insecticide, you need to identify the kind of mealybug attacking your pregnant onion.

Final Thoughts

The pregnant onion is such a visually-appealing and easy-to-grow houseplant, preferably for first-timers. Compared to other indoor plants of this caliber, it’s one of the less demanding plants you’ll ever come across.

All you need to do is give it the right amount of sunlight exposure it needs and observe the few tips we just shared in this guide.

If you need to clarify or share any extra insights on growing and maintaining the pregnant onion, don’t miss to drop a line or two right in the comment section below.

5 Comments
  1. Great info. I have two questions: I will be repotting my small sea onion and family soon. Its in a plastic pot now and quite low in pot. Can i change to clay pot(i tend to overwater)and plant a tad higher? Ive not had much luck with houseplants lately. Thanks

  2. I purchased my pregnant onion from a nursery, and did not know anything about it. It has a few babies but had no leaves. I repotted it and the stem coming out of the top now appears to be rotting. I think it may have gotten frostbitten. Will it recup, or should I return it and cut my losses?

  3. The leaves 🍃 have a medicinal feature to cure minor infections. Cut a piece of the leave, tap gently to get some juice out of it, place it on the infected area.
    Leave it over night. The next morning the infection is gone.

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