The Helenium is a large daisy-like flower that blooms late summer into early fall. Unfortunately this is not always the case and many of the bought in plants have been raised under over-protective cover making them vulnerable when first planted. For long term control use surface mulches of chopped or shredded twiggy material. Transplant the flowers outside when the air is cool and there is still possibility of a frost. From late July to September, Helenium autumnale 'Helena' blooms with masses of vibrant blooms in a spectrum of rich colours from gold to mahogany red. 0 Reviews. Sow seed in greenhouse in early spring or sow directly in garden in mid-spring. Good companion plants are taller grasses, other daisy flowers such as echinaceas, or hot-coloured kniphofias. Heleniums have charming, daisy-like flowers, guaranteed to bring vibrant colour to the garden in late summer. Helenium 'Moerheim Beauty' is known for attracting bees, beneficial insects, birds, butterflies / moths and other pollinators. They are colourful, tolerate difficult growing conditions, provide months of colour, are attractive to pollinating insects and unaffected by most pests and diseases. Cultivation: Floaters are sterile and should be discarded. The first selection in the U.S 'Riverton Beauty' gained an Award of Merit (AM) in 1909, this was quickly followed by a number of other cultivars. Once flowering has ceased and the plant has died back the stems should be cut down. Click to share on Facebook (Opens in new window), Click to share on Twitter (Opens in new window), Click to share on Pinterest (Opens in new window). Sooner or later, Google will find all new spam methods. Helenium are very easy to grow, all this plant needs is sunshine and well-drained soil. “I told my wife, ‘They don’t look like any flower seed I had ever seen,’” he said on Sunday. The large and numerous daisy-like, yellow flowers of Helenium autumnale can provide welcome color in late summer and autumn when many other blossoms have disappeared. Always wait until the spring before dividing the plants. If there's one plant that can inject a little razzle-dazzle into the border during our gloomy late summers it is Helenium. Propagate from seed or by division in early spring. The website speed test at Secret Search Engine Labs will analyze how fast a page on your site is loading and give Maintenance: Regular removal of spent blooms will prolong flowering. *I wait until late May before planting out after having hardened them off in preparation for the outside world. How to Plant. Garden Grow Premium Portable 6 Shelf Greenhouse. Heleniums are much under-rated garden plants. Fertilizer: Scratch in a balanced organically-sourced, granular fertilizer each spring. Because Helenium is easy to raise from seed…will flower in the first year…and of course you will get a whole host of plants from a packet rather than just one plant for £6.99. Transplant helenium seedlings into the garden 12-18 in. Deadhead heleniums constantly to promote more flowers. You can also grow heleniums from seed and even get flowers the year they are sown. In early spring the soft new growth can be damaged by slugs - some varieties seem more prone than others. The upright, leafy, branching stems emerge from sturdy clumps. Annual species are easily grown from seed, and perennials should be divided every year in order to retain their vigor. 10:58 am. When planting, barely cover the seeds with soil. it is at once effective and refined which cannot be said of all the yellow flowered composites." Plant Uses: 19 Reviews. Well suited for cottage gardens, prairie plantings or naturalistic areas. The colors look terrific together, and also with black-eyed Susans, ornamental grasses, yarrow, and Russian sage, or around the base of tall Joe-Pye weed. Plant prefers part shade and evermoist soils, although full sun will be tolerated. The dazzling colour range makes a spectacular autumn display in perennial borders. Helenium Helena Red Shades Seeds H. autumnale. Despite its common name, it presents no problems for most allergy sufferers. Sow Helenium seeds indoors 8 to 10 weeks before the last frost. Its pollen is distributed by insects, not wind. Very adaptable to a variety of soils, including dry conditions, they are very hardy, reported as able to withstand temperatures down to minus 40°C (-40°F). *Sow on the SURFACE of your seed compost…just firm them in. * When to cut back. They come into bloom from the end of summer until the first frost. Sneezeweed plants (Helenium autumnale) produce pretty little daisy-like flowers, sometimes in shades of pale yellow and sometimes in rich, autumn shades such as gold and reddish-brown. We had to wait until 1940 for Karl Foerster to introduce his first Helenium. Place in a propagator or seal container inside a polythene bag until after germination which usually takes 14 to 21 days at 18°C (64°F) but may be erratic. Grow Helenium: Plants perform best in full sun. It is commonly called Helen’s Flower If there's one plant that can inject a little razzle-dazzle into the border during this gloomy summer, it is Helenium 'Sahin's Early Flowerer'. Just £1.99. Plant Helenium Seeds: Sow helenium seeds in cell packs or flats, press into soil but do not cover. The chop delays flowering time - so they perform later. Common name: Sneezeweed. Helenium flowers look similar to coneflowers in that petals face outward from a central cone in a ray shape, or may droop downward. With perennial plants like Heleniums we always look to buy online from nurseries which grow their own plants rather than buy them in from sources unknown to you. Selected, named and described by Inez Arnold in the Netherlands. Sneezeweed Seeds 6980 (Helenium autumnale). This variety looks best … Most garden varieties range between 60 and 120 cm, and have daisy like flowers of red, orange or yellow. Helenium make very attractive cut flowers Your delightful common or garden petunia plants (Petunia spp., Petunia x hybrida) are actually members … These easy to grow flowers love full to partial sun. Like all daisies, heleniums need a bright, sunny position. A hardy perennial which carries vivid daisy-like flowers from July to October. Helenium found in: Helenium 'Moerheim Beauty', Helenium hoopesii, Helenium 'Lemon Sundae', Helenium autumnale 'Helena Rote Töne', Helenium autumnale .. In the U.K. during the late 1950s and 1960s, Alan Bloom and Percy Piper at Bressingham began breeding Heleniums. Quick Buy. I think they look great in the vase with Achillea ‘Cerise Queen’ and a good fist full of Borage…it’s an odd colour combo but it does it for me. Common sneezeweed can be found in much of the United States, in moist to wet openings, edges, shores, and thickets. It was described as -"Among the more showy herbaceous plants this is one of the best . Blooms attract butterflies, make excellent cut flowers. Later sowings can be overwintered in a coldframe and planted out the following spring. Helenium Californicum This looks and grows very much like the wild species H autumnale * Helenium Can Can Attractive warm tawny yellow reminiscent of Zimbelstern. Just £44.99. Eight Months At Bluebell Cottage Nursery. A tall border plant with masses of vibrant blooms generally edged with yellow top tall border plants. I may add a couple more Helinium next season but for the moment I have settled on ‘Goldfield’ to get the ball rolling. Helenium flower seed is a native American perennial, so you know it is right at home in the sunny garden. But by 1930 a plant revolution had taken place. With common names of Helen’s flower, sneezeweed (somewhat misleading since they do not cause allergies but got that name from the historic use of … Gorgeous, two-toned petals unfurl in shades of yellow, orange, rust and mahogany, revealing a strong and sturdy center cone. Helenium is a genus of annuals and herbaceous perennials in the sunflower family native to the Americas. To restrict their size, cut back to about 30cm tall in May. Prolific bloomers, Coreopsis produce masses of showy single, semi-double or double daisy like flowers, mostly in … From late July to September, Helenium autumnale 'Helena' blooms with masses of vibrant blooms in a spectrum of rich colours from gold to mahogany red. While many herbaceous plants can be divided in the autumn, heleniums are an exception and are best dealt with in spring just as they are starting into growth. Quick Buy. These late flowering perennials are a mainstay of the summer and autumn border but are so often overlooked. The colors look terrific together, and also with black-eyed Susans, ornamental grasses, yarrow, and Russian sage, or around the base of tall Joe-Pye weed. Bright yellow is the most common color of helenium flowers, but you’ll also find orange, fiery red, and bicolor blooms. Self-Watering Seed Starter Kit . Some common names for members of Helenium include Yellow Star, Sneezeweed, and False Sunflower. Why? These easy to grow flowers love full to partial sun. Add glorious late-season color to your landscape with helenium, a sun-loving perennial that delivers long-lasting floral displays each year from mid to late summer through fall. This variety will flower the same year from an early sowing giving a spectacular, late summer display. This variety will flower the same year from an early sowing giving a spectacular, … What to Do with Peony Seed Pods. . This variety will flower the same year from an early sowing giving a spectacular, late summer display. Nomenclature: Should your heleniums wilt, pour buckets of water gently on to the roots and they will revive. Deadheading heleniums. The Helenium genus contains plants that are hardy perennial in nature. Use it in borders, cottage gardens, and naturalized areas. Heleniums are found growing in a wide variety of conditions but very often in moist or even wet habitats. For Mardi Gras our recommended supplier is Seed Sower. Prick out each seedling as it becomes large enough to handle, transplant into 7.5cm (3in) pots. 3 Options From £8.99. This is frankly a little silly. *Helenium plants like moist soil…and cool soil if possible…so a layer of mulch will really help them along. How to Get Seeds From the Petunia Flower. Also known as Sunny Bride. Sowing: February to June or September to October Division: Wait until growth has started, probably from mid March onwards when growth has started but stems have not lengthened too much and some new root growth has started. Each flower head has up to twenty reflexed petals some edged with yellow. Not only do Heleniums look good in the garden but they are also as great cut flowers and good for bees. Helenium look tremendous paired with almost anything, but especially with grasses, and look stunning planted in mass. The flowers can sometimes look like they have a petal or two missing, but they are none the less beautiful. Sneezeweed ... and they look wonderfully in bouquets. Plants will not reach their final height until their second year. Most garden varieties range between 60 and 120 cm, and have daisy like flowers of red, orange or yellow. Grow Helenium ‘Moerheim Beauty’ in fertile, well-drained soil in full sun. Bright yellow is the most common color of helenium flowers, but you’ll also find orange, fiery red, and bicolor blooms. Quick Buy. This dependable perennial blooms from late summer into fall with numerous bright yellow pin-cushion flowers atop tall stems. Workhorses in sunny borders, these American native prairie plants also make excellent cut flowers. If there's one plant that can inject a little razzle-dazzle into the border during our gloomy late summers it is Helenium. It looks superb in mass plantings, or planted between clumps of Crocosmia. As you divide it is easy to separate and remove the old and dead material which was the previous year's growth. Helenium 'Moerheim Beauty' and wildlife. You May Also Like. The Helenium is a large daisy-like flower that blooms late summer into early fall. Apply one annual application of organic fertiliser when coming into growth in the spring. 2 Options From £12.99. Cottage/Informal Garden, Flower Arranging, Flowers Borders and Beds. incredibloom® 133 Reviews. Helenium autumnale is a flowering plant native to North America. Sowing Biennial Flower Seeds In June And July. They will do best where afternoon or morning sun falls. These will take root very readily, and should be planted in rows about a foot asunder, and 9 or 10 inches distant in the rows. Every third year is ideal. This not only reduces their final height but will also delay flowering by a week or two. But it seems Memorial You will not get the same plants as the parent so you cannot call them by the parent’s name. The viable seeds that sink should be rinsed with 10% bleach. The plant can reach 48 inches tall and 18 inches wide, with dozens of flowering stems. Seeds will sprout within 10 days, and the idea temperature for seeds to germinate is 70 degrees. July 2, 2014 @ But do be bold and use large blocks of the same helenium - if you have room. Planting Potted Plants: Choose a location in full sun with moist, well-drained, organic soil. If there's one plant that can inject a little razzle-dazzle into the border during our gloomy late summers it is Helenium. *I tend to wait util things start to warm up in April before sowing. You can divide as small as you like right down to a single rosette with its roots. This species prefers loamy or silty soils that are high in organic matter. Those of you who know the Higgledy Garden site well will know I am slowly adding new stock but only when I’m sure that the chosen variety is right for the job. The large and numerous daisy-like, yellow flowers of Helenium autumnale can provide welcome color in late summer and autumn when many other blossoms have disappeared. The Gardeners' Chronicle of 1878 shows a delightful, though hardly accurate, line drawing of Helenium autumnale. Flowers are produced early July to early October. Great for cutting. Rather, the geranium plant is quite secretive when it comes to making seeds, so if you want to collect them, you will have to take a … A rich chromatic scale of bronze, brown, crimson and yellow for an end-of-summer display. With perennial plants like Heleniums we always look to buy online from nurseries which grow their own plants rather than buy them in from sources unknown to you. Prepare the bed by turning the soil under to a depth of 6-12 inches removing any debris, and lightly raking as level as possible. Helenium autumnale seeds for sale. *Space plants to a foot or a foot and a half. They combine particularly well with grasses and other late-flowering perennials in prairie-style plantings. Don’t expect to see these seeds though by just looking at the plant! Helenium autumnale was introduced to Europe from North America in 1729. This dependable perennial blooms from late summer into fall with numerous bright yellow pin-cushion flowers atop tall stems. It grows widely, from Quebec to Florida and from British Columbia to Arizona, it is found in wet meadows, thickets, and even swamps and river margins. You must have JavaScript enabled in your browser to utilize the functionality of this website. (NB It won’t appear in the shop quite yet.). His 1964-66 catalogue lists 19 Helenium varieties of which 17 were his own. Use it in borders, cottage gardens, and naturalized areas. Height: 120cm(48in) Width: Depth: All heleniums respond to dead-heading so take off any spent flowers as they fade, more will appear in their place. February to June or September to October. Growing to a height of 120cm (48in), it is perfect for the back of the border and the long stems are wonderful for cutting. Mass planting, Bee and wildlife gardens. Other daisies in varying colours also work well as long as they are taller and airier. You can take helenium tip cuttings from the new growth in April. USES OF HELENIUM IN THE LANDSCAPE Helenium is good for naturalizing and generally looks best planted as a grouping or as a mass planting. Like all daisies, heleniums need a bright, sunny position. Kept at 70°F, seed germinates in 10-21 days. Sneezeweed prefers full to partial sun and wet to wet-medium soils. Very adaptable to a variety of soils, including dry conditions. Foerster is reported to have introduced some 73 forms but just how many remain in cultivation today is unclear. you tips on how to improve it. Helenium autumnale is the most widely distributed species. Reportely able to withstand to minus 40°C (-40°F). The types most commonly used as garden plants are hybrids created with H. autumnale as a primary parent. The plant can reach 48 inches tall and 18 inches wide, with dozens of flowering stems. This perennial variety will flower the same year from an early sowing giving a spectacular, late summer display. Helenium, aka 'Sneezeweed', is a native flowering perennial that produces late-season blooms that butterflies rely on. A very charming and free flowering plant whose Inca gold cone centre acts as the perfect landing pad for the thousands of bees that will come to pay homage to Miss Helen of Troy. Add glorious late-season color to your landscape with helenium, a sun-loving perennial that delivers long-lasting floral displays each year from mid to late summer through fall. This low-maintenance flower is deer resistant and does … The showy petals surround a spherical brown cone covered with golden pollen that attracts butterflies. Some people also give heleniums a Chelsea Chop, but only do this on deep, fertile soil. They are easy to grow and reliable in any fertile soil and tolerate quite a bit of moisture (a good candidate for the moist to mesic area of a rain-garden). Helenium Sneezeweed flowers bloom like crazy all over sun-loving plants from early summer right into fall -- a dazzling sight indoors or out! With blooms in hot yellows, orange and red, they look fantastic planted in drifts through a mixed border. 15 Reviews. Helenium look tremendous paired with almost anything, but especially with grasses, and look stunning planted in mass. Pests and diseases are mercifully rare in Heleniums. Helenium Gay-go-round (orange-) red, broad yellow margin, orange behind, somewhat like a Gaillardia; fading to a yellow-orange-red blend; height 160 cm. They need light to germinate. A hardy perennial which carries vivid daisy-like flowers from July to October. Seeds may be sown, either when ripe, in cold frames, or in spring in the open. The centres become more prominent as the flowers age and the petals curve backwards. Light-dependent germinator (plant on surface or only very shallowly covered, so light can penetrate). Helenium autumnale is named after Helen of Troy, it is said that these flowers grew where her tears fell…the ‘autumale’ suffix means it is late summer/autumn flowering. After collecting peony seeds, place them in a bowl of water to test their viability. The simplest method is to tear apart an established clump into as many pieces as necessary. Direct sowing can take place in the early spring or the early fall. These beautiful blooms have a prominent central cone surrounded by bright petals. You can distinguish helenium from coneflowers by its late summer into early fall bloom time; in contrast to the early summer blooms of coneflower. *Plants can be divided in about three years…do this in spring not winter. Grow on in cool, well lit conditions at 12 to 15°C (53 to 59°F). JavaScript seems to be disabled in your browser. While many herbaceous plants can be divided in the autumn, heleniums are an exception and are best dealt with in spring just as they are starting into growth. You have no items in your shopping basket. Flowering begins in late summer or early fall and continues for 1-2 months. Sneezeweed prefers full to partial sun and wet to wet-medium soils. *Helenium seeds are best started off in pots or modules. Prick out when large enough to handle. A comparison of the Heleniums that we grow all collected together on one page along with descriptions and extra information to help you make your choice Heleniums generally produce abundant velvet-textured flowers in dense terminal clusters over a long period of time. From late July to September, Helenium autumnale 'Helena' blooms with masses of vibrant blooms in a spectrum of rich colours from gold to mahogany red. They have a common name, swamp sunflower, which is not surprising. Too much fertilizer cause plants to … Single flowers resemble Coreopsis but have a large center button like coneflower, and cover the tops of branching upright 45' plants. I'm far too lazy for that sort of caper. It looks superb in mass plantings, or planted between clumps of Crocosmia. There is no chill requirement so seed can be sown in early spring – say late February or early March in N Europe given greenhouse or cold frame protection. Photo Inez Arnold (copyright waived). 3 Options From £6.99. The genus Helenium is said to be named by Linnaeus after Helen of Troy, according to the legend that these flowers sprang up from the ground where her tears were supposed to have fallen. There are about 40 species of Helenium in North and Central America. Google Helenium varieties 'Sahin's Early Flowerer' AGM The best and earliest helenium for garden use is a long … Some Heleniums flower in mid summer but generally they arrive at the disco fashionably late. The helenium flowers bloom from early summer to fall and can also be enjoyed as cut flowers in a vase. You may get away with autumn division with a large clump but … Rusty brownish seed clusters follow. The helenium flowers bloom from early summer to fall and can also be enjoyed as cut flowers in a vase. This not only acts as a physical deterrent to slugs, more importantly it provides an excellent habitat for those fast moving small black beetles which are superb slug predators - in particular slug eggs. These beautiful blooms have a prominent central cone surrounded by bright petals. autumnale) By Sue Trull, Ottawa National Forest. Native to both North America and Europe, this sun-loving plant is sometimes called sneezeweed (because it was once used for making snuff). Looking just a bit like sunflowers, heleniums, or sneezeweed, are bright and cheerful perennials in shades of gold, rust, orange, and red.They flower in the fall with huge masses of two-inch blooms on branched stems three to five feet tall. This was named 'Kupfersprudel' and once he had started his output was prolific. A very charming and free flowering plant whose Inca gold cone centre acts as the perfect landing pad for the thousands of bees that will come to pay homage to Miss Helen of Troy. A comparison of the Heleniums that we grow all collected together on one page along with descriptions and extra information to help you make your choice Soil pH: Does best in slightly acidic to neutral soils, but will tolerate most pH levels. I am lacking in photos for ‘Goldfield’ but will source some soon enough….remain calm. This highly floriferous perennial is dwarfer, compact and early flowering. Quick Buy. Once every two months, I send subscribers a discount code or an offer for a heavily discounted bundle of seeds. The species name autumnale is from the Latin autumnus and the adjectival suffix alis meaning "of or pertaining to the autumn”, usually flowering then. The garden forms also show a preference for damp conditions but will tolerate any soils except very dry ones. Gradually acclimatise to outdoor conditions before planting out 30cm (12in) apart. Helenium ‘Goldfield’ has bright golden yellow petals that are slightly down turned…perhaps ‘hangdog’ in nature. Helenium flowers also differ from coneflowers in color, and don't exhibit the pink and purple coloration that coneflowers do. Bringing warm colour to borders from mid-summer into autumn, these sun-loving perennials are tough, hardy and easy to grow. Do note that this plant, including its flowers, foliage, and seeds, are poisonous if ingested and can potentially cause vomiting or convulsions. . Common sneezeweed is a perennial plant in the daisy or aster family (Asteraceae). Elecampane (Inula helenium) is a perennial herb in the aster family with a long history of medicinal uses. Helenium is one of those perennials that people rarely grow from seed and instead buy plants from the garden centre. Needs light to germinate. Heleniums are easy plants to propagate. The compost should be kept slightly moist, but not wet at all times. Culture: Frost hardy, they prefer full sun (at least 6 hours of direct sun), well, drained soil and regular water. Its abundant yellow blooms can be found in late summer to fall, often attracting bees and butterflies. Masses of vibrant blooms. Helenium bigelovii, bolanderi, and hoopseii are native to Oregon. Common sneezeweed (Helenium autumnale L. var. 14 Reviews. They come into bloom from the end of summer until the first frost. These daisies come in a choice of rich, fiery hues – yellows, deep oranges and reddish-coppers – opening from mid-summer. Cover with a very fine sprinkling of compost. The common name Sneezeweed is believed to be derived from the former use of the dried leaves to make a snuff. Like the sun setting over the desert, Helenium autumnale Western Mixture will embrace any border with a yellow-red glow from summer until the very end of autumn. Heleniums (sometimes called sneezeweed) are very much low maintenance, flowering perennial plants (slugs aside at their early stages) which can grow from as low as 60cm / 2ft to 2m / 7ft high depending on variety. Birds feast on their seeds and butterflies love their nectar. Helenium: Potted Plant Perennial. Quick Buy. It is best propagated, however, by off-sets, taken in the autumn from the old root, with a bud or eye to each. But they also need moisture-retentive soil and prefer alluvial loam. As with many border plants, the material growing on the outside is the most vigorous and the best to use. They can be pruned in June to keep the height lower but … With a name like Sneezeweed its hard to become a best selling garden plant, but don’t despair, it won’t make you sneeze. It nectar-pollen-rich-flowers and has seeds … Helenium make very attractive cut flowers The showy petals surround a spherical brown cone covered with golden pollen that attracts butterflies. The Plants Database includes the following 21 species of Helenium .Click below on a thumbnail map or name for species profiles. Helenium ‘Goldfield’ has bright golden yellow petals that are slightly down turned…perhaps ‘hangdog’ in nature. This was inhaled by native Americans to promote sneezing and rid the body of evil spirits. Thanks to its true branching habit, Western Mixture offers masses of stunning yellow, red and bicolour red/yellow flowers. Harvested peony seeds can be planted immediately, directly in the garden or indoors in seedling trays or pots. Helenium Sneezeweed flowers bloom like crazy all over sun-loving plants from early summer right into fall -- a dazzling sight indoors or out! Helenium grows in clumps from a crown (L, in early spring) with lanceolate leaves with sparsely toothed to almost entire margins (R). Origin: CULTURAL & MAINTENANCE NEEDS: Helenium autumnale is easy to grow in most sunny sites. Recent introductions are now coming from a number of enthusiasts, particularly in the Netherlands and Germany. In appearance, it is reminiscent of a sunflower plant, with tall stalks, pale green foliage, and bright yellow flowers with large seed heads in the center. The name sneezeweed, by the way, not only grates on the ear, it is also inaccurate, since heleniums are not in the least allergy-provoking, {{var product.name}} was added to your basket, {{var product.name}} was removed from your basket. Meanwhile in Germany, the first plant catalogue of Karl Foerster had appeared in 1907 but as late as the 1939 his list did not contain a single Helenium. If soils are dry it will help to include plenty of well rotted humus to retain moisture. Doyle Crenshaw of Booneville, Ark., said he had planted some of the unsolicited seeds he got. Do not exclude light at any stage, as this helps germination. It is easier to separate small pieces if the plant is washed in water. They blend perfectly with grasses, bee balm, yarrow and other late season bloomers. The genus Helenium in the daisy family (Asteraceae) includes more than 40 species of annuals and perennials from the Americas. Masses of vibrant blooms A tall border plant with masses of vibrant blooms generally edged with yellow top tall border plants. Helenium. Plants grow 3-5’ tall with 3’ spread. This clump forming plant’s unfortunate name came from its medicinal use by native North Americans as the crushed dried petals were used to combat hay-fever. Why you should be sowing Hardy Annuals in late August/early September. You may get away with autumn division with a large clump but the disturbance followed by a cold wet winter will often kill smaller pieces. Native to both North America and Europe, this sun-loving plant is sometimes called sneezeweed (because it was once used for making snuff). Some common names for members of Helenium include Yellow Star, Sneezeweed, and False Sunflower. Day wasn’t important enough to Google. Helenium is an upright annual, biennial or herbaceous perennial with simple leaves and showy daisy-like flowerheads in late summer and fall. Offered in the past as Sneezeweed Supposedly used for snuff in earlier times, hence the sneeze. Buy Helenium 'Moerheim Beauty' from Sarah Raven: My long-standing favourite helenium with orange-crimson flowers.
2020 what do helenium seeds look like