Atropurpureum Allium

Upon Arrival:

Plant the bulbs as soon as possible once you have received them. If you cannot plant the bulbs as soon as they have been shipped to you, remove the bulbs from plastic bags and put them on trays with damp peat moss or sawdust in a cool, well-ventilated place until you have a chance to plant them. Do not store them at temperatures below 4°C. Generally all bulbs planted in the fall are hardy and do not need any special protection unless specified.

Where to Plant:

The most important rule when planting bulbs is to choose an area that is well-drained. Most bulbs will rot or deteriorate quickly where soil is constantly damp. Most bulbs thrive in full sun, or at least 5-6 sunny hours daily. Some bulbs such as fritillaria and wood hyacinths prefer filtered shade. Within each individual bulb or perennial variety it is stated what type of light conditions are preferred. Planting Bulbs: Plant bulbs individually by digging a hole for each bulb with a trowel or bulb planter, or place several bulbs on the bottom surface of a larger hole, then cover with soil. As planting depths and spacing varies depending on the type of bulb, refer to the cultural information found later in this guide.

Whichever method you use, be sure to loosen the soil at the bottom of the hole and work in a handful of organic fertilizer such as Veseys Bulb Fertilizer. Then press each bulb firmly into the soil, top pointing up and fill in the hole. When in doubt as to which way is up on a bulb, plant it on its side and let 'Mother Nature' decide! After planting, water the area well to settle the soil and to start the roots growing. If rainfall is sparse, you may need to water the bulbs once a week to help them get established. For strongest visual impact, we suggest planting your bulbs closely in groups, drifts or clumps of a single kind and colour.  When planting bulbs, be sure to take colour into consideration. In general, groups of a single colour have the most impact.

Planting Allium:

Plant 20 cm bulbs 10"-12" apart and 6" deep; 10-12 cm bulbs 8" apart and 4" deep; smaller bulbs 3"-4" apart and 3" deep.

Growing:

All thrive in sun and will tolerate some shade. Although Alliums are drought tolerant, they will do best in soil is that is well drained. The tall varieties should be planted in groups of at least 3 bulbs toward the back of the garden: the shorter varieties in groups of 6-10.

Note: The foliage of many larger alliums, withers just as the plant blooms, so plant behind bushy perennials, such as daylilies or hostas.

Fore info: https://www.veseys.com/ca/growing-from-bulbs-and-roots/