Allium Growing Information

Flowering Onions

Our alliums are in the same family as garlic, onions, chives and shallots. Ornamental gardeners sometimes wonder if including alliums will cause their borders to smell like salad bars.  Not to worry.  The scent, when present at all, is mild and noticeable only when the leaves are bruised or crushed.  Onion family bulbs are unappealing to rodents, however, and that's a real plus.

What flowering onions will bring to your landscaping are interesting forms, mostly globe flowers on slim, straight stems, and often, incredible size.  Some blooms are as large as soccer balls and perch atop 3½  foot stalks.  Few plants can provide that kind of drama.

If you garden with children, be sure to include allium.  Kids love these!

Outdoor Beds

1.  Find a location where the soil drains well.  If there are still water puddles 5-6 hours after a hard rain, scout out another site.  Or amend the soil with the addition of organic material to raise the level 2-3 inches to improve drainage.  Peat moss, compost, ground bark or decomposed manure all work well and are widely available.

2.  Site your allium where they will get full day sun. 

3.  Dig holes and plant the bulbs 3” deep and 6”-8” apart.  Position the bulbs with the pointy end up.  

4.  After planting, water well, thoroughly soaking the area.  Roots and sprouts will form in the autumn.  Flowers will develop in the spring. 

5.  When in bloom, feel free to cut allium flowers for bouquets or for drying. 

6.  After blooming has finished for the season leave the foliage in place; don't cut it off.  The leaves will gather sunlight and provide nourishment for next year's show.  Water as needed during active growth periods. 

7.  By mid summer the leaves will yellow and die back as the plant slips into dormancy.  Foliage many be removed at this point.  Your alliums will rest for a few months before beginning the next growing cycle.

Pots, Tubs & Urns

1.  Fill your containers with good quality, well-drained soil.  Almost any commercially available potting medium will work fine.  Make sure there are adequate drainage holes; allium bulbs must never sit in waterlogged soil or they will rot.

2.  Site containers where they will receive full day sun. 

3.  Plant your alliums 3" deep and 6" apart for the most brilliant display.  Position the bulbs with the pointy end up.  

4.  After planting, water the bulbs well, thoroughly soaking the soil.  Roots and sprouts will form in the autumn.  Flowers will develop in the spring. 

5.  After blooming has finished for the season leave the foliage in place, don't cut it off.  The leaves will gather sunlight and provide nourishment for next year's show.  Water as needed during active growth periods. 

6.  By mid summer the leaves will yellow and die back as the plant slips into dormancy.  Foliage many be removed at this point.  Your alliums will rest for a few months before beginning the next growing cycle.