The name Allium is from the ancient name for garlic, which is part of the genus. There are estimated to be around 700 species within the genus, and many cultivars. There are perennials and biennials. Many members of the genus give themselves away with the distinctive smell of onions when the bulb or foliage is bruised.

Characteristics of Purple Sensation – Allium hollandicum

- A fall planted ornamental onion bulb, will produce purple flowers.
- This flower is sure to turn heads with its 4-inch wide globes of tightly packed pink-purple florets which sit at the top of a tall, thick, bare stem.
- In summer it bears umbels 8cm (3in) across of 50 or more star-shaped, deep violet flowers.
- Contact with bulbs may irritate skin.
- They are great for ornamental value and widely used for both landscape and cut flower purposes.
- The Allium Purple Sensation is ideal for containers, mass plantings, borders, and cut flowers.
- These plants are rabbit, squirrel, and deer resistant.
- The Purple Sensation has a bloom period of about 3 weeks and they bloom in late spring to early summer.

How to grow Purple Sensations

- Flower bulbs should be planted at least two and a half times the height of the bulb.
- They should be far enough so that they do not touch.
- Frost should be avoided while rooting.
- When planting in grass areas mowing should not take place until the
leaves have died off (about six weeks from planting.)
- Do not tie up or knot the foliage as this cuts off food supply.
- Plant in groups of ten or more for an eye catching focal point.

Basic Requirements to grow Purple Sensations

- Soil should not be too wet.
- Soil should be well drained but should have good moisture retention as flower bulbs are not deep rooted.
- Plant bulbs 5-10cm (2-4in) deep in autumn.
- The ideal PH level is approximately 6.5.
- It grows well in full sun or partial sun.
- The growth rate is moderate.
- Fertilizer is not essential but a dressing of a high potash and phosphate fertilizer may prove beneficial.

Photos of Purple Sensation on Flickr (link)
Allium ‘Purple Sensation’ (Allium hollandicum ‘Purple Sensation’) – Photo (link)
Allium hollandicum ‘Purple Sensation’ (detailed photo) (link)

- Sunset Hyssop is an open herbaceous perennial with an upright spreading habit of growth.
- The leaves are fine-textured with a gray-green color. In the summertime, sunset hyssop is covered in trumpet shaped flowers, each with shades of orange, pink and purple.
- Sunset hyssop is a surefire way to attract hummingbirds to your garden. The vibrant pink, purple and orange blossoms definitely catch your eye, adding pizazz to any yard. It is able to grow in many zones and soil conditions.
- It brings an extremely fine and delicate texture to the garden composition and should be used to full effect.
- This perennial will require occasional maintenance and upkeep, and is best cleaned up in early spring before it resumes active growth for the season.

Growing Tips For Sunset Hyssop

- Plant in a sunny location. It can tolerate part shade if needed.
- In the first season, they should be watered regularly to establish the root system. The soil should be well drained as sunset hyssop does not tolerate soil that is constantly wet. After it is established, it is very drought tolerant.
- During spring, you can divide established plants.
- Sow seeds directly in the garden once temperatures are above 55 degrees. Space transplants 12-18″ apart.

Maintenance/Pruning For Sunset Hyssop

- Cut sunset hyssop almost to the ground at the beginning of spring. This will promote stronger and more vigorous growth. Deadhead spent flowers to extend blooming season.
- In colder regions, mulch with pea gravel during the winter. Do not use wood mulches; these tend to keep the soil below very moist, which this plant cannot tolerate.

Soil Conditions needed for Sunset Hyssop

Sunset hyssop prefers a hot, sunny spot in well-drained, mineral-rich, humus-poor soil. Cut the fine-textured, somewhat brittle stems down close to the ground at the beginning of the growing season, even if much of the wood remains live, as it does in warmer zones. This radical pruning promotes sturdier, more vigorous growth.
Sunset hyssop is short-lived in damp, cool climates and resents moist winter soil. Otherwise it appears to adapt to most garden situations as long as it has full sun. Its warm colors and full, bushy texture combine well with late-season grasses such as Mexican feather grass and the taller big sacaton, two other lovely Southwest natives. Late- blooming, similarly drought- tolerant plants such as blue mist spirea, Russian sage, and Maximilian sunflower also make good companions. This recently discovered treasure offers lively color and delicious fragrance, while bringing wildlife into our late-season gardens.

There are some problems that are associated with Sunset Hyssop like : Mildew, rust, and downy mildew.

Most articles that you about how to plant specific plants do not fail to mention as to what should be the spacing between plants. The spacing between plants is important as it helps in deciding the overall growth of the plants; too little space and they end up competing for the same nutrients, for soil, and even for sunlight. In such cases, the growth can be severely limited, and you may be disappointed in the end with the plants that finally emerge.
Now, combine this with the advantages of growing multiple plants together (if done with good planning and knowledge, you can reduce the competition between plants, with some plants maybe depending more on the nutrients from soil and others less, and in excellent cases, some plants replenishing nutrients in soil that other plants have extracted). The question that emerges is what should be the spacing between plants when you have different plants.
This site (link) attempts to explain this, and even provide an online calculator to explain in more detail:

Mixed planting, or companion planting, can offer benefits over monocultures:
o Mixed crops often have higher yields than monocultures because different species use different resources, making more efficient use of land.1
o Mixed plantings often have fewer pest problems than monocultures because pests have a harder time finding suitable hosts, or because diverse plantings provide better habitat for natural enemies.
Although mixed plantings are common, practical resources for those who grow mixed crops are few; production guides and extension materials are often based on the assumption of monoculture.

So, it is actually a recommendation that if you have a kitchen garden where you grow plants and fruits for your own use, then consider the option of mixed planting, and if you that, do refer to the linked article.