Allium Planting Guide

Garden lollipops. Purple puffs on stems. Botanical balloons. See these fun, lighthearted flowers blooming in a garden and you can be sure that the adjoining home is occupied by a person who finds humor and levity in life’s little things. Kuddos to them for sharing! After all, who could refrain from smiling at the sight of a giant purple globe the size of a soccer ball?

Choosing a Growing Site

Choose a site with full to ¾ day sun for your alliums. The tallest, most spectacular varieties flower best in full sun settings. Yellow flowering Moly is happy in sun or part shade.

Soil Prep for Alliums

Alliums are not fussy and will thrive in average garden soil. As with most bulbs, good drainage is important to help avoid bulb rot.

When to Plant Alliums

Allium bulbs are sold in the fall and should be planted when the soil has cooled but is still warm enough to be worked. Allium bulbs should not be held over for planting in the spring; it's necessary for the bulbs to root in over the winter so they can absorb the moisture and nutrients needed to thrive.

How to Plant Allium Bulbs

Loosen the soil to 6 inches deep and blend a handful or two of compost into the soil you removed. Place a bit of the amended soil back into the holes and plant your allium bulbs at a depth that is 3 times the diameter of the bulb. Little bulbs are planted about 3” deep while the larger ones get tucked down 6-7” deep. Plant with the pointy end of the bulb facing upwards. Refill the hole with soil, pat to eliminate air pockets and water well to settle the soil around the bulb.

For spacing, plant 6-7 bulbs per square foot for Moly, drumstick alliums, pink lily leeks, ramsoms and Azureum. For the large flowering varieties, plant 12-15” apart.

During the Growing Season

Allium plants need about 1” of water a week from rain, irrigation or a combination of the two.

At Season’s End

After flowering, your alliums' foliage needs to stay in place, photosynthesizing to nourish the bulbs for next spring’s flowers. When the leaves yellow their work is done and they can be removed.

Insider Tips

  1. Plant 6-7 bulbs per square foot for smaller varieties and bulb spacing of 12-15” for the giant flowering types.
  2. Rodents, rabbits and deer have little interest in allium bulbs, foliage or flowers, making these outstanding plants for areas where critter damage is a concern.
  3. Alliums are excellent for cutting and add an attractive round/oval design element to spring arrangements. Mix with foxtail lilies, callas, peonies and irises.
  4. If you live in a warm part of the country, where spring arrives early, make sure to plant your outdoor alliums by late November to give the bulbs time to root in. Otherwise, they may begin to sprout before supporting roots have developed. 
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Success Snapshot

Light: Full sun to partial shade

Soil: Average soil; enrich with compost

Depth: Plant 3-7” deep, see left for details

Water: Average moisture

Uses: Spectacular forms for landscape and cut flower designs

Tip: Easy care and critter-proof

GUIDE: Allium Planting Guide

They Start Out Looking Like This: