Sowing summer: black-eyed Susans for every garden

The days are getting longer and winter is drawing to a close.
March is upon us and Vermonters are getting serious about planning for the gardening season ahead. What new garden projects should we undertake  and what new plants will we try?
It is also ‘seed-starting month’ in the North Country. If you sow seeds indoors in March, the young plants will have a two-month head start before you move them to their long-term garden home.
Most of us are familiar with those cheery Black-eyed Susans that bloom in our gardens each fall. But many lesser known varieties will light up your beds from mid-summer onwards. And a couple of these are best started from seed right now.
So, in the spirit of something new for this year’s garden, may I suggest you try some different kinds of Black-eyes Susans that you have not grown before.
Not only will their exuberant flowers bring pleasure to you and your family throughout the summer,  but they will also provide nectar for the bees and, if left standing in winter, their seeds will be enjoyed by the birds.
All-American Black-eyed Susans
There are more than two dozen species of Black-eyed Susans, all with distinctive yellow petals radiating out from a central knob. And all are native to North America.
And while some species have additional names — such as daisies, sunflowers or coneflowers — they all belong to the Rudbeckia genus. Hence we often collectively refer to all the members of the Black-eyed Susan clan as “Rudbeckias.”
Many Rudbeckias are perfectly at home in our gardens.  Some are tall, others short; some would look great in a mass planting near the house whereas others could become the mainstay of a new meadow garden.
And are also dozens of cultivated varieties of Rudbeckias — known as “cultivars” in horticultural parlance — with names like Gloriosa Daisies, Indian Summer, Denver Daisy  and Cherry Brandy, that plant breeders have developed especially to provide desirable features such as mammoth flowers, luscious colors, or more compact plants.
Where to plant
Most rudbeckias will flower most prolifically in full sun, although some, like the perennial cultivar Goldstrum, will also bloom nicely in partial shade. 
Rudbeckias also vary in height, bloom time and number of flowers each plant produces, so keep these attributes in mind when choosing plants for a particular location.
Many Rudbeckia varieties including Cherry Brandy, Denver Daisies, Gloriosa Daisies, Indian Summer, the Clasping Sunflower and Goldstrum, grow between two and three feet tall, making them perfect near the front of the border. To make your Rudbeckias stand out, combine them with grasses that have contrasting textures, such as Tussock Grass (Deschampsia cespitosa) or Prairie Dropseed (Sporobolus heterolepis).   RUDBECKIAS COME IN different sizes. Here the shorter Goldstrum Rudbeckia occupies a “front of the border” spot, while the much taller Autumn Sun looks great at the back alongside beside Miscanthus grasses.
Photo / Dick Conrad
Long blooming cultivars such as Cherry Brandy, Denver Daisies and Gloriosa Daisies are also ideal for container plantings, perhaps mixed with a soft Blue Fescue grass.
Since Sweet Black-eyed Susans (Rudbeckia subtomentosa) as well as the cultivar Autumn Sun both grow five feet high or more, they belong near the back of the border, perhaps in front of some tall Miscanthus grasses.
For a naturalized or meadow garden, where all plants need to be both robust and enduring, choose the cultivar Goldstrum together with a few wild species, such as the roadside Black-eyed Susans (Rudbeckia hirta),  the Clasping Sunflower (Rudbeckia amplexicaulis) and Sweet Black-eyed Susans (Rudbeckia subtomentosa).
Annuals or perennials
Some species of Rudbeckia are annuals, others biennials and still others are long-lasting perennials. Some are even described as “short lived perennials.”
For example, the Clasping Sunflower, is an annual. Its seeds germinate in the spring, produce flowers and set seeds all in the course of a single summer. Although those original plants will not survive the winter, next spring their seeds will sprout and continue the cycle.
However the familiar roadside Black-eyed Susan (Rudbeckia hirta) — as well as its cultivated offshoot, the stunning Gloriosa Daisies — are naturally biennial (meaning they germinate in the spring but only flower in their second year). 
However, if you plant the seeds of either Gloriosa Daisies or the roadside Black-eyed Susans indoors around now, you will be rewarded with flowers this first year. 
And while some of those plants may return and flower for a few more seasons — and thus are sometimes described as short-lived perennials — you cannot count on it. Just enjoy it when it happens.
Still other Rudbeckias are true long-lasting perennials.  While they may not begin blooming as early each season, if you choose a perennial variety like the familiar cultivar Goldstrum (Rudbeckia ‘Goldstrum’)  or the very tall Autumn Sun (Rudbeckia ‘Herbstonne’) they will return year after year to light up your fall garden.
Seeds or young plants
Typically if you try growing cultivars from seed, the new plants do not always retain the desired characteristics. So for varieties like Indian Summer (which has enormous flowers between 6-inches and 9-inches across), Denver Daisy (with upward-facing yellow and reddish petals around sultry brown cones) and Cherry Brandy (with deep pink petals), your  best choice is to seek out young plants at your local garden center.
Gloriosa Daisies, a tetraploid cultivar with twice the normal number of chromosomes, however, is the exception to this rule. When grown from seed the new plants do retain their distinctive features, including huge flowers, both singles and doubles, in a wide range of colors — and all from a single pack of seeds. Start them indoors now for a summertime show.
However, if you want to cover a big area with a mass of plants, perhaps a large flower bed or even a meadow planting, then your least expensive  approach would be to buy bulk seeds of one or more of the wild species, and plant them directly where you want them to grow.
First loosen the soil and remove all the weeds. Now broadcast the seeds across the entire area and water gently. Do not cover the seeds since they need light to germinate. 
American Meadows, an internet company located in Burlington, sells bulk seeds for several Rudbeckia species, including the roadside Black-eyed Susan (Rudbeckia hirta), the low growing Clasping Sunflower (Rudbeckia amplexicaulis), and the taller Sweet Black-eyed Susans (Rudbeckia subtomentosa), any of which would be ideal as part of a large meadow planting.
Almost all Rudbeckias will self seed, ensuring you flowers in future seasons.
However some of our favorite varieties, like Goldstrum, Indian Summer  and Cherry Brandy, have been developed by plant breeders for their special colors or larger flowers. If these are allowed to self-seed, next year’s plants may not come true to type. If this concerns you, plan on dead-heading your plants as each stem completes flowering. 
And, as an added bonus, following a regular deadheading routine will trigger the plant to make additional new blooms — something worth considering too. 

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