Alliums are a popular bulb flower that add gorgeous globes of color to the garden. With their drumstick-shaped blooms in shades of purple pink yellow, and white, it’s no wonder gardeners love to grow these ornamental onions. The good news is propagating alliums is simple, allowing you to multiply your plants for free. In this comprehensive guide, I’ll explain everything you need to know about how to propagate allium plants so you can increase your collection with ease.
Why Propagate Alliums?
There are several great reasons to propagate alliums
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Save money. Buying allium bulbs every year can get expensive. Propagating your own bulbs from existing plants saves you the cost of buying new ones.
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Multiply your plants. Starting with just a few allium bulbs, you can increase your stock exponentially through propagation. This allows you to fill your garden with more flowers.
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Share with friends. The bulbs you propagate can be gifted to fellow gardeners. Alliums make a lovely housewarming or birthday gift.
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Preserve hybrids or heirlooms. By propagating special allium varieties in your garden, you can preserve beloved plants that may not be available commercially.
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Control spread. Some alliums like chives can spread aggressively. Containing them to a designated area by propagating in pots helps prevent them from taking over.
How to Propagate Alliums
Alliums are propagated through division, offsets, seeds, or bulblets. Let’s look at each method.
Division
Dividing established clumps of bulbs is the easiest way to propagate alliums. Here’s how:
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Dig up clumps after foliage dies back in late summer. Gently separate bulbs, ensuring each has roots.
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Replant divisions 8-12 inches apart and 3 times as deep as the bulb’s height.
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Water well until established. Blooms should appear the following spring.
Large clumps may yield 6-12 new bulbs when divided. Dividing overcrowded clumps every 2-3 years also helps improve flowering.
Offsets
Many allium species produce offsets, new young plants. Once flowering is over and leaves have died down, you can lift the bulbs and detach the offsets. Either plant them directly in their final positions or grow on outside in pots of gritty compost.
For the best results, detach offsets that are at least 1/3 the size of the parent bulb. Smaller ones may not bloom for a couple seasons.
Seeds
Though slower, propagating from seed is doable. Allow seed heads to fully dry on the plant after blooming finishes. Then collect the black seeds and sow immediately 1⁄4 inch deep in pots.
Keep the seed starting mix moist but not soggy. Move pots to a bright, cool spot to overwinter once sprouted. Transplant seedlings to the garden after 1-2 years when bulbs have formed.
Bulblets
A few alliums like garlic chives produce aerial bulblets instead of flowers. Once the umbel dries, harvest the tiny bulblets and sow them 1/2 inch deep in gritty compost. Keep moist and in partial sun. Pot up the developing bulbs the following year.
Tips for Successful Propagation
Follow these tips to ensure your propagated alliums grow strong and bloom beautifully:
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Use disease-free bulbs and sterilized tools to prevent spreading issues.
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Choose plump, firm bulbs and offsets with no mold, rot, or pest damage. Discard any diseased sections when dividing.
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Use sharp knives or tools to avoid crushing bulbs and damaging roots when dividing.
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Replant bulbs at proper depth and spacing to prevent overcrowding.
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Provide well-draining soil amended with compost. Alliums hate wet feet!
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Water thoroughly after planting and fertilize bulbs in early spring.
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Allow seeds, offsets, and divisions 1-2 years to establish before expecting flowers.
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Propagate in containers to control spread or isolate new plants if disease is a concern.
Common Allium Species for Propagation
While methods remain the same, bloom time and plant size can vary by allium species. Popular types to propagate include:
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Chives: Dainty, early blooms and edible leaves. Spread rapidly.
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Giant alliums: Large, dramatic globes up to 12 inches wide. Includes A. giganteum and ‘Gladiator’.
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Drumstick alliums: Unique, slender blooms. Good for borders. Try A. sphaerocephalon.
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Ornamental onions: Showy, midsize blooms in purple or white. Such as A. caeruleum.
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Garlic chives: Produces aromatic, edible foliage and aerial bulblets instead of flowers.
With a little time and care, propagating alliums by division, offsets, seeds, or bulblets is an easy and gratifying way to multiply your collection of these stunning ornamental bulbs. Use the techniques outlined here to save money, share plants with friends, and fill your garden with many more of these iconic vertical blooms. The ability to propagate your own assortment of alliums will bring you joy for years to come.
Sowing the Future: Propagating from Seeds
Harvesting Allium narcissiflorum seeds is all about timing. When the flowers have faded and the seed heads turn brown and crispy, its showtime. Gently collect the seeds, ensuring theyre mature and undamaged—think of it as picking your dream team for the garden league.
Prepare your seeds for the big leagues by cleaning them up, removing any plant debris. Some seeds might need a cold stratification period; its like their winter training camp before the spring season starts. If thats the case, mimic nature by giving them a chill in moist sand for at least 60 days.
Planting Dreams: Sowing Seeds
Soil mix is the foundation of your seeds future success. Aim for a lightweight, well-draining mix thats the gardening equivalent of a comfy bed—your seeds will thank you by sprouting eagerly.
Moisture is the secret sauce for germination, but its a fine line. Keep the soil consistently moist but not waterlogged, like a perfectly damp sponge. Its the difference between a sprout and a dud, so pay attention and adjust as needed.
How to Propagate any Plant |Multiply Your Plants for Free!|
FAQ
How to propagate allium from cuttings?
Can alliums be propagated?
Do alliums self-propagate?
How do you get allium to spread?
Can you grow alliums from seed?
Allium bulbs are usually planted in fall. But if you are growing alliums that produce seed, you can also propagate the plants from seed as well. It’s an easy and cost effective way to increase the number of allium plants in your garden. Not all ornamental allium plants will produce seed however, and some will produce only a few.
How do you propagate alliums?
Transplant the seedlings into their permanent positions when they are large enough to handle. Stem cuttings are another way of propagating allium plants, but it is not always successful. Take stem cuttings from healthy parent plants in spring or early summer. Cut a section of stem about 10cm long with a few leaves attached.
How do you plant Allium seeds?
Allium seeds can be planted in cell trays, or alternatively in open trays filled with a soilless medium. Fill cell trays or open trays full of soilless medium. Place one or two seeds in each cell. If planting in an open tray, sprinkle the seeds on the surface of the medium in the tray. Cover with more of the same medium.
How do you collect Allium seeds?
There are several options for collecting allium seeds. You can harvest the entire seed head along with the seeds, or alternatively tap the seeds into your bag or container, allowing the seed heads to remain in the garden. Collect on a dry day when the seed heads are not moist from rain or heavy dew.