More than any other garden crop, starting alliums from seed gets me enthusiastic. They announce the end of winter, which by February is the only story I want to hear. They are a brilliant green sign of spring.
The earliest seeds that can be grown indoors belong to this plant family, which also includes leeks, chives, garlic chives, onions, scallions, and many more less well-known species. In the Northeast, onions and leeks transplant best from February 1 through March 10 and produce the largest bulbs and shanks (but I’ve had outstanding crops from mid-March sowings and passable harvests from late-March to early-April direct sowings). More tolerant of starting times are scallions, chives, and garlic chives. Scallions in particular benefit from succession sowings in the spring and summer.
Allium seeds can be easily sown. The deeper the tray, the better. Fill it with potting soil that has been supplemented with compost. Then, create and firm down furrows along the length of the tray that are approximately 2″ apart. In these furrows, scatter the seeds thickly at a rate of 6 per inch. A different technique for growing onions and scallions is to fill six-packs with enriched potting soil, moisten it, and then make a dibble in the middle of each cell that is a quarter-inch deep. Each dibble should contain 6-8 onion seeds or 12–15 scallion seeds before being filled with potting soil. (This latter approach has the benefit that transplanting is simple. Simply extract the entire plug and transplant it after thinning the cells to 3-5 plants apiece. They will happily reach their full size in a clump that is simple to weed around if you place them in the bed about 12″ apart.)
At room temperature, alliums germinate most well. As long as you start them early enough, you should be able to wait the 7–10 days it takes for them to emerge at room temperature even if they pop a little faster with heat because the germ rate actually decreases. Unlike other seedlings, they prefer to be kept moist and grow most robustly when their feet are nearly continually wet. Rather tragically, these wet conditions also contribute to damping off, the primary issue that onion seedlings experience. Compared to almost any other seedling, onions are more susceptible to damping off and other fungal diseases. Growing onions indoors at room temperature in nicely moist soil with regular air flow is optimal. A little fan works wonders for this. As with other seedlings, make sure there is enough light available.
Alliums are typically advised to develop until they are pencil-thick before being transplanted. However, it is difficult to accomplish this by transplant time, which is roughly 6 weeks before the final frost, even with an early- to mid-February start date (early- to mid-April here in upstate New York). I believe that aiming for seedlings with a diameter of between 1/8 and 1/4 inch is a more practical objective. These size seedlings are simple to nurture, transplant well, and begin to grow within a day or two. They yield large onions, thick leeks, and quickly growing scallions. The wiry, thin seedlings are frequently successful; they are not useless. But before starting to grow again, they may waste days or even weeks appearing to be nearly lifeless. Tip: Start your seeds in a very deep tray—say, six to eight inches—if you want particularly thick seedlings. Some growers accomplish this using a window box.
The most challenging aspect of growing alliums from seed is locating the ingredients for quality potting soil in the bitter cold of winter. There are several closed garden centers. Most likely, your personal compost pile is frozen. And even though the outside garden centers at big-box home stores are typically open all winter, they are typically only selling off their remaining inventory from the previous season and frequently lack essential components. Your best option is definitely to purchase organic potting soil from a reputable garden center’s indoor section, but by all means, add some compost, organic fertilizer, or perhaps both. Alliums are nutrient-demanding plants that require fertile soil for the best results; mixtures supplied in tiny bags for houseplants and similar plants typically have insufficient nourishment.
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 long does it take for alliums to grow from seeds?
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.
Can you grow an allium plant from seed?
Alliums are magnificent plants, therefore it’s worthwhile to save a few seeds to plant in the spring to increase the number for the garden.
It’s fascinating to grow cultivars and see what you get even though the seeds won’t be true to type. The seeds will sprout swiftly and mature into flowers in a few years. To obtain the finest show, when planting, pick a place that is protected, sunny, and has excellent drainage.
Try tapping the seeds directly into a paper bag if you want to keep the seedheads in the garden for winter interest. The cut seedheads could potentially be used again in indoor arrangements.
Can allium seeds be saved?
Excellent bulb plants for perennial gardens are ornamental alliums. They are attractive onions, which come in a variety of species and cultivars.
Their sizes range from the smaller “Allium sphaerocephalon, a smaller allium, to Allium giganteum, a larger allium.
The majority of people grow alliums from bulbs since it is relatively simple to do so.
However, you can also start new plants from seeds if you are raising alliums that produce seeds. Increasing the number of allium plants in your garden is simple and affordable.
However, not all attractive allium plants will, and some will only produce a small amount.
A few varieties of allium are sterile and won’t set seed. In the case of cultivars like Allium “Globe Master” and Allium “Mount Everest,” this is true.
Some cultivars, like Allium, produce a lot of seeds “Allium christophii, also known as the Star of Persia, and Purple Sensation
The seeds from alliums that produce seeds can be kept, planted, and grow to produce more allium seedlings for the garden.
Is It Worth Growing Alliums From Seed?
Growing alliums from seed is absolutely worthwhile if you want to enhance your allium supply.
Remember that some allium bulbs, particularly the larger types, can be rather expensive.
Therefore, gathering some allium seed will ultimately save you money if you have a larger cultivar that produces seed and wish to grow your allium stock.
It’s crucial to understand that hybrids won’t be true to the parent plant, and that the new seedlings may have differences in size, form, and color.
Can allium seed heads be 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.