It’s fascinating to grow cultivars and see what you get even though the seeds won’t be true to type.
Should you remove the alliums’ seed heads?
Alliums, which include onions, leeks, shallots, chives, and garlic, were once only considered to be vegetables, but today’s taller species with their enormous spherical flowerheads are among the most prominent members of the architectural plant community. Their stiff lollipop-shaped heads are ideal for counterbalancing tall, poker-shaped flowers, softer flowing grasses, and sharp vertical leaves, while their rich color—typically purple—looks stunning either in contrast to warm reds, yellows, and oranges or mixed with cooler tones of lilac, blue, and white.
Alliums can reach heights of up to 200 cm, with flowerheads ranging in size from small pompoms to enormous spheres of star-shaped blooms. For rock gardens at the front of the border, the little types work great. Garlic and chives grow well in these conditions, and they have the added benefit of confusing aphids and other bothersome insects so they go for food elsewhere. To ward against pests, surround other veggies and delicate plants like roses with these smelly plants.
Alliums are attractive not just when they are fully bloomed; the fallen flowerheads can also be left on the plant to dry and add architectural interest in the fall and winter. Hard frost will make the globes, especially those of Allium christophii, look gorgeous. For an eye-catching interior arrangement, you may also cut the flowers fresh and combine them with iris and thousand-flowered Gypsophilla.
Growing guide
Alliums prefer a warm, sunny location with healthy, rich soil. They can live in a more sandy area, but they will need to be well mulched if they want the truly magnificent huge heads. Since they are perennial bulbous plants, you can either plant them as potted plants year-round or as bulbs in the fall, putting them up to 15 cm deep. The plants will quickly take root and typically bloom the following year. Being bulbous also means that plants will eventually generate small offsets around the parent, forming large clumps.
Propagation
Any very big clumps can be separated into smaller portions in the late summer and replanted. Additionally, offset bulbils can be used to propagate new plants (newly formed, little bulbs). The majority of bulbils develop underground around the initial bulb. These can be carefully broken off and buried 1 cm deep in grittier compost. Aerial bulbils are produced by the Allium sphaerocephalon variation and emerge from the flowerhead. The same procedure as above can be used to plant these.
A content allium will freely self-seed. You can gather the seeds from the plant before they fall if you like to control where your new plants will sprout up (as opposed to leaving it up to chance and chaos). As soon as the heads (and stems) start to turn brown, remove them. Place in a paper bag so you can catch the seeds as the pods split open. The seeds can be kept in the bag in a cold location until the following spring, or they can be sown straight into the soil where you want them to grow. It can take up to a year for some alliums to germinate, so patience is essential.
Pest alert
Alliums are typically healthy plants, yet during a humid time they might get white rot and downy mildew. Since they belong to the onion family, they may experience onion fly attacks. Yellowing leaves are a typical early sign, and as white maggots eat away at the roots, the plant will abruptly collapse. Because the maggots are so deeply embedded in the soil and even in the bulb itself, this pest is particularly challenging to eradicate. Dig up any afflicted plants to get rid of onion flies so that the maggots can’t develop into adults, pupate, and create more grubs.
Variety guide
The most well-known flowering allium is undoubtedly A. giganteum, which grows up to 1.8m and produces 10-15cm-diameter spherical heads of purplish-pink flowers. Despite their size, almost never do they need to be staked. It looks lovely placed beside another monster, the grass Stipa gigantean, in the back of a border as a focus point. Another choice is the 80cm tall cultivar “Globemaster,” which grows best between shrubs in a sunny border and adds a dash of deep violet to the season with its enormous 15cm wide spherical flowerheads. Allium sphaerocephalon, which has stunning two-tone maroon and green flowerheads, may be the prettiest member of the clan. When combined with grasses or other globe-headed flowers like Echinops and Eryngium, it makes a stunning border plant.
The rich rosy-purple flowers of Allium hollandicum ‘Purple Sensation’ make it a charming addition to a sunny border. It will reach a height of 1 m. It looks especially beautiful when planted with fennel with feathery leaves. A. karataviense is ideal for the rock garden because it only grows to a height of 25 cm. Large, delicate pink blooms with unique leaves with dark crimson edges adorn the plant. Another option for a rock garden or for growing in a pot on the patio is the variety “Ivory Queen,” which is even shorter at 20cm tall and thrives in dry soil in a sunny location.
Crocus tip
Many of the taller alliums’ foliage will already be starting to die back by the time the blooms bloom, but if they are surrounded by perennials with appealing foliage (such herbaceous geraniums), these unkempt leaves can be covered.
Container plants
Alliums prefer a sunny location with well-drained soil, but if they are planted in pots, they must not be allowed to dry out in the spring as this can prevent the flower buds from opening.
Should I remove alliums once they flower?
Post-bloom maintenance for alliums is quite simple. Simply continue to water the plants sparingly until they start to shrivel and turn yellow. At this point, you have the option of either dividing the plants or cutting them all the way to the ground.
Divide allium bulbs every three to four years. Simply use a shovel to dig around the plant and lift the bulbs out. You should see a group of bulbs that you may gently separate with your hands. Replant a few in the same location, and immediately transplant the others to different sites.
It’s considerably simpler to take care of allium bulbs that you don’t wish to divide. When the foliage starts to fade, simply trim it back, and in the fall, mulch the soil with 2 to 3 inches (5-7.5 cm) of material. In the spring, remove the mulch to allow room for fresh growth.
How are allium seed heads preserved?
I have an obsession with ornamental alliums. I keep growing more of them even though I now have around a dozen distinct varieties in my garden. Alliums are not only stunning to look at, but they are also long-blooming, pollinator-friendly, and appear to be immune to disease and pests, even deer.
And if that’s not enough, alliums’ seed heads are yet another reason to adore them. The seed heads of these late spring/early summer flowers can be an equally alluring lure after they have faded. They provide unique forms and textures to the yard and summer flower arrangements and many of them will survive for months. Continue reading to discover how to maximize the use of these eye-catching seed heads.
Use Allium Seed Heads in Fresh Arrangements
While they are still green, the seed heads can be clipped and added to bouquets of fresh flowers. Homegrown bouquets are given a distinct glitter by their color, shape, and texture. For this, Allium Purple Sensation works best.
Leave Seed Heads Right in the Garden
The seed heads can be left in the garden, where people will continue to be intrigued by their unique textures and shapes. The Globemaster and Gladiator alliums, which have sturdy, robust stems, are the ones that I find last the longest. Allium Christophiii’s seed heads, however, also persist for a long time. They may continue to look nice into August in a dry summer.
Paint the Dried Seed Heads
Another choice is to paint the seed heads once they have completely dried. Last year, I dried some Gladiator seed heads and used gold spray paint to embellish them. They emerged with a little bronzer appearance than gold. I might attempt silver paint this year.
The dried seed heads have also been painted glossy white and utilized as wedding decorations by me. The Gladiators are those displayed below.
Here’s a way for drying allium seed heads so you can paint them or just display them inside. When the seed heads are dry but before the seed capsules start to open and release the seeds, they should be painted or treated with a clear fixative. You can maintain the starburst effect and reduce the amount of seeds you need to sweep up by placing the seeds inside the capsules at the end of each “stem.”
The enlarged seed capsules are visible in the photo below, even though the seed head is not yet dry enough to paint.
Visit this post on Gardenista to see some lovely dried alliums (Allium schubertii) hanging from the rafters of an old stone barn in Wiltshire, England.
Mid- to late-fall is the ideal time to plant decorative alliums. Orders are accepted starting in May, and bulbs are shipped from early September through mid-November. The only way to guarantee you’ll get the variety you desire is to place your order early. Our entire collection is available to view HERE.
Are allium bulbs formed from the seeds?
The growing requirements for these relatives of common onions are the same whether you are growing alliums for their eye-catching, globular flowers, like the Star of Persia (Allium christophii or A. albopilosum), or for their flavorful, pungent bulbs, like leeks (A. ameloprasum) or chives (A. schoenoprasum). Depending on the variety, both types of alliums can be grown in USDA hardiness zones 3 to 11, producing edible bulbs or blossoms in the spring, summer, or fall before withering away in the winter and regrowing the following year.
How soon may I prune back alliums?
No matter if they are beautiful or not, alliums can be multiplied through seed, bulbs, or division. As they normally don’t blossom for at least a year or two, if not more in some situations, starting from seed demands patience.
Also bear in mind that if a plant in your garden is a hybrid type, seeds you save from it could not grow true to the parent plant.
Provide well-draining, somewhat sandy soil for these lovely bloomers. If your yard is made of hard clay, add some sand to assist drainage because they don’t thrive there.
To find out whether you need to amend the soil, you could also wish to perform a soil test.
Flowering alliums only require well-draining soil, but you should make any necessary adjustments if your soil is substantially deficient in any of the three major nutrients: potassium (K), phosphorus (P), or nitrogen (N).
From Seed
You can buy seeds or use the ones you’ve saved from a prior growing season (more on that below).
After any chance of frost has passed in the spring, soften the soil where you want your plants to grow and scatter the seeds over it. Don’t bother properly spreading the seeds one at a time because they are little. Simply disseminate them widely over the growth area.
To avoid disturbing the seeds, cover them with 1/4 inch of dirt and water them thoroughly using your hose’s soaker attachment. Till the first green sprouts appear, keep the soil moist. After that, you can cut back on watering so that the top inch of soil can gradually dry out between applications.
Once the plants have emerged, thin them to the suggested spacing specified on the seed packet. The space required for different sizes of alliums vary.
By Division
Allium plant division is a fall task. It’s a good idea to divide your plants every three to four years to maintain their health and make sure they are evenly spaced.
At the end of the growth season, four to six weeks before the first frost, trimming back any remaining leaves and flower heads is the first step.
Allow a six-inch space around each plant as you excavate nine inches down. Although the roots of ornamental alliums are not particularly deep, you should try to minimize disturbance.
Remember that alliums can develop from rhizomes or bulbs, as was already indicated, but the procedure for digging them up and splitting them is the same for both.
Lift the soil mound with your shovel, then gently pry the bulbs or rhizomes out.
Put one of the bulbs back where it was growing after separating the others, at the same planting depth as before you dug it up. If you haven’t treated your plants in several years, mix a little bulb fertilizer with the soil.
Rhizomes can be divided by cutting them in half with a sharp knife. Reposition one of the rhizomes’ halves at the same depth where it was developing.
Plant the extra bulbs the same way you would new bulbs or transplants, which we discuss in the section after this one.
If you are unable to plant the bulbs immediately away, keep them in a cool, dark place for a few months. Rhizomes can be kept in the refrigerator for about a week in a plastic bag.
Planting Bulbs or Rhizomes
The procedure for planting bulbs is the same whether you purchase them from a neighborhood store, online, from a friend, or through division.
If you haven’t tested your soil, be important to do so before planting in the late summer to see if any supplements are needed.
Fork or shovel the ground in the fall, six to eight weeks before the first frost.
If desired, incorporate some bulb fertilizer, such as Jobe’s Organics Bulb Fertilizer, which is sold on Amazon.
How are allium heads dried?
By planting fall bulbs for spring blooms, we are already thinking ahead for the garden of the next year. Alliums are among our favorite bulbs to plant in the fall because they promise to produce enormous, eye-catching flowers. Because of their extraordinary height, they can be used in formal or casual gardens as well as naturalized landscapes. They are whimsical yet dignified. Additionally incredibly adaptable and durable, alliums are perfect for year-round decorative use. Continue reading for our instructions to growing, drying, and using these garden giants as decorations.
Planting Select a planting place with well-drained soil and full sun as soon as the leaves start to fall. This will help your alliums grow stronger stems. These huge bulbs, which can rot if exposed to too much moisture, require good soil drainage. For each bulb, dig a hole that is 2-3 times as deep as the bulb’s height, measured from the bottom of the bulb. Place the bulb in the ground with the pointed end facing up, completely cover it with dirt, and give it a good watering to help it settle. If you’re planting several bulbs, make the holes about 6 to 8″ apart. In the fall and winter, roots will begin to grow, and in the spring, leaves and flowers will appear.
Find a spot for alliums where they may tower over other plants without getting blown over by the wind. The majority of allium stems are robust and sturdy, but as they get older, they might break and become untidy. Never allow the stake extend past the ball if you decide to stake an allium as it grows. Alliums can benefit from having mounding plants around them, such as hardy geranium and nepeta, to help hide the leaves as it turns yellow later in the season.
Drying The majority of allium cultivars bloom in the late spring and early summer, but if they are left in situ, they can keep the garden going into the fall and even the winter, becoming a tawny gold. Their pointed seedheads, however, can also be carried inside and dried for ornamental purposes. Pick a drying location first when you’re prepared to take your alliums from the garden. A pantry or closet may be the best location because they are cool, dark, have good ventilation, and have low moisture levels. To suspend the allium stems, run a taut strand of twine or wire across the area.
When the seedheads are fully developed and dry, harvest them, leaving the stems intact. Make bundles of two or three stems using rubber bands after trimming any extra leaves. Your alliums can be suspended separately if they are quite large. The seedheads should dry for three to six weeks after you attach the bundles to your drying line (we like to use an unfolded paperclip for this).
Decorating Once dried, seedheads make amusing embellishments for both the home and yard. When placed within a glass cloche with other preserved flora, they develop into a natural collection. Tall stems provide new plantings, like a hanging basket or a barrel of autumn grasses, architectural interest. We’ll also add dried alliums to wreaths and evergreen trees as the holidays get near for a botanical Christmas.