Friday, June 29, 2012

Rudbeckia - Where Black-Eyed Susans Grow

Rudbeckia 'Spotlight'
One of my earliest heart-felt memories of early childhood is of walking in our front yard overlooking the river waist-deep in Black-Eyed Susans. Now the sight of them anywhere recalls those halcyon days. And there are many reminders, for Black-Eyed Susans are native to North America. According to the USDA PLANTS Database, there are few states where at least one species can't be found in the wild.

It's believed that English colonists gave the flowers their common name inspired by a popular romantic poem of the time, Black-Eyed Susan by John Gay (1685-1732).

ALL in the Downs the fleet was moor’d,
  The streamers waving in the wind,
When black-eyed Susan came aboard;
  ‘O! where shall I my true-love find?   
Tell me, ye jovial sailors, tell me true
If my sweet William sails among the crew.’   

William, who high upon the yard
  Rock’d with the billow to and fro,
Soon as her well-known voice he heard
  He sigh’d, and cast his eyes below:
The cord slides swiftly through his glowing hands,
And quick as lightning on the deck he stands.

Then the lovers embraced,

The noblest captain in the British fleet   
Might envy William’s lip those kisses sweet.

Sweet William commenced to assure her that he would be safe even in battle, and true to his vows. Finally,

The boatswain gave the dreadful word,
  The sails their swelling bosom spread,
No longer must she stay aboard;
  They kiss’d, she sigh’d, he hung his head.
Her lessening boat unwilling rows to land;
  ‘Adieu!’ she cries; and waved her lily hand.

Perhaps the memories of parting and the colonists' own travels came to mind.

The naming of genus Rudbeckia (pronounced rud-BEK-ee-a) isn't so romantic, but worth knowing. It was named for Olof and son Olof Rudbeck, well-known Swedish scientists of the 17th and 18th centuries. Olof the Elder, (1630-1702), also known as Olaus, was best known for his work in medicine and linguistics, but also for his accomplishments in botany, astronomy and music. A professor at Uppsala University, he established Sweden's first botanical garden there. It became known as Rudbeck's Garden.

Olof the Younger (1660-1740) continued in his father's footsteps, succeeded his father's professorship at Uppsala, excelling in ornithology, botany and linguistics. One of his best-known students was another famous Swede, Carl Linneaus (1707-1778), the botanist who devised our system of taxonomy. Quite naturally, Linneaus honored the Rudbecks in the genus Rudbeckia. Rudbeck's Garden was later re-named Linneaus Garden.

Of the 30 or so Rudbeckia species, I admire a few particularly.

Rudbeckia hirta may be the most common. It grows almost everywhere unplanted and untended. You'll find it along roadsides, in fields, and maybe wild in your yard, too. You've probably picked them for bouquets. There are several varieties. Rudbeckia hirta var. pulcherimma is hardier than the rest. You'll find it growing from Florida to Canada. It's mostly biennial at best, meaning that it flowers the second year and dies. In the south, R. hirta may flower the first year and die, but not before it re-seeds itself. In fact, that's the beauty of Rudbeckia hirta; it's easy to start from seed. Perfect for planting your own wildflower meadow.

Rudbeckia hirta has been used medicinally for many years. It's said to boost the immune system, so was used to treat various infections.

Maybe you remember the Gloriosa Daisy. I do. It was a big hit when introduced back in the 1950s. Gloriosa Daisy resulted as an attempt to perennialize R. hirta. That didn't work. But Gloriosa Daisy is still popular because the flowers are much larger than the species, in nice mixtures of colors, and sometimes double. It's ideal for naturalizing. I also remember my mother being disappointed that Gloriosa Daisy didn't return year after year.

Several new Rudbeckia hirta cultivars have been introduced recently promising longer than biennial lives. The jury is still out. Don't count on Rudbeckia hirta as a perennial yet, but enjoy it for what it is. Gloriosa Daisy is hardy in USDA climate zones 5 to 10.

Rudbeckia fulgida 'Goldsturm'
If you want a dependable native perennial that looks like Rudbeckia hirta, plant Rudbeckia fulgida or it's offspring. R. fulgida is the honored grandparent of most hybrid perennial Black-Eyed Susans. Its various varieties are the parents. These varieties are distinguished by slight differences. Plant producers look to those differences to selectively breed into new hybrids.

Rudbeckia fulgida var. sullivantii is the parent of the most popular Black-Eyed Susan, Rudbeckia fulgida var. sullivantii 'Goldsturm'. Developed in Germany, the name means "gold storm." It certainly is. The flowers are golden yellow, large and abundant, appearing for weeks from mid-summer to fall. It's so tough, you'll find it in planting beds around gas stations and shopping malls. Not surprisingly, it was named the 1999 Perennial Plant of the Year by the Perennial Plant Association. R. fulgida var. sullivantii is hardy in USDA climate zones 3 to 9.

Rudbeckia fulgida var. speciosa is almost exactly the same as var. sullivantii, but shorter. Common names include Eastern Coneflower, Orange Coneflower, Showy Coneflower. 'Viette's Little Suzy' is one to look for. 'Little Suzy' is named after a family of plant hybridizers in the U.S. R. fulgida var. speciosa is hardy in USDA climate zones 4 to 8.

(Note that the common name, Coneflower, is also shared with the related genus, Echinacea. They are not to be confused, though some Echinaceas were once named among the Rudbeckias. .)

Rudbeckia lacinata, known as Cutleaf Coneflower, is a tall one, sometimes growing 9 feet high. The large flowers with drooping petals are light lemon yellow. It's too tall for planting in the front of perennial beds, but perfect for planting in the rear. The petals fluttering in the breeze add motion and interest to the border. The disadvantage of its height is that it needs support to keep it from falling over.

Back in 1894, a seedling of R. lacinata named 'Golden Glow' was introduced to an appreciative gardening audience. Showy double blooms and shorter height (about 5 feet) made it very popular. But like its parent, it also needs support. 'Golden Glow' is still available, but superseded by an offspring named R. lacinata 'Golden Drop.' 'Golden Drop' only grows to 3 feet. If you want to plant a "heritage" garden featuring old-fashioned, heirloom species, Rudbeckia lacinata is a "must have." It's hardy in USDA climate zones 4 to 8.

Rudbeckia maxima
Rudbeckia maxima, also known as Great Coneflower and Cabbage Leaf Coneflower, grows to 6 feet. The medium yellow flowers sport prominent cones. It's native to Texas and surrounding Gulf states. Rudbeckia maxima is known to be hardy in USDA climate zones 6 to 8.

Rudbeckia nitia is tall, like R. lacinata and R. maxima, but the large, golden yellow flowers have green centers. It's commonly called Shining Coneflower. R. nitida should be considered a protected species, so don't collect it from the wild. From it, plant breeders have produced a wonderful new plant called 'Herbstsonne.' 'Herbstsonne' means "autumn sun." Enormous flowers on tall 6 foot plants really attract attention. This, too, is perfect for height and drama in the perennial border. 'Goldquelle' is a shorter version with double flowers. 'Goldquelle' means "bonanza". It deserves the name. R. nitida is hardy in USDA climate zones 4 to 10.

Rudbeckia subtomentosa is another desirable species. It's commonly called Sweet Black-Eyed Susan. You'll find it growing wild in the central United States. Height is about 4 feet. The flowers are especially fragrant. 'Henry Eilers', a cultivar, displays large golden blossoms with tubular petals, somewhat resembling yellow wagon wheels. R. subtomentosa is hardy in USDA climate zones 4 to 10.

Rudbeckia triloba
Rudbeckia triloba, commonly known as Three-lobed Rudbeckia or Brown-eyed Susan, is very hardy, thriving in USDA climate zones 3 to 10. Bright yellow flowers with big brown centers really attract attention. Plants grow to 4 feet. Two cultivars, 'Prairie Glow' and 'Red Sport' produce bright orange flowers with yellow tips.

Rudbeckias perform best in full sun, but will tolerate partial or light shade. Soils should be well-drained soils with pH ranging from 5.6 to 7.5.  Take a soil sample to your nearest Cooperative Extension Service office for proper analysis.

Prepare the planting bed by cultivating at least 6 inches deep, removing all traces of weeds. Compost may be incorporated into the soil.  Incorporate 10-10-10 fertilizer at a rate of no more 2 lbs. per 100 square feet into the top 4 inches to 6 inches of soil. Avoid synthetic fertilizers contacting any part of your plants.

If planting seed, sow according to instructions on the seed packet.

If planting container-grown plants, space larger ones 24 inches to 36 inches apart. Dig planting holes into the cultivated soil a little less deep than the depth of the growing container.  Water the plants in the pots, then drain.  Place the plants into the holes and back-fill, watering as you go. Press soil around the root balls. Do not cover entirely the root balls with soil. The tops should be slightly exposed. Add a top-dressing of mulch around the plants, not on top of them, about 1 inch deep.

Plant Rudbeckias with other plants having similar cultural requirements.  Fertilize sparingly and allow soil to dry between watering.

All Rudbeckias attract butterflies. Birds get enthusiastic about the seeds. All Black-Eyed Susans are reasonably drought-tolerant. They're especially suited to naturalizing, wildflower meadows, cutting gardens, wildlife gardens, native plant collections, heritage and cottage gardens. But they're wonderful in any perennial garden or border, even at gas stations and shopping malls.

Where should Black-Eyed Susans grow? Probably in your garden. Certainly in your heart.

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Rudbeckia hirta 'Prairie Sun'

Tuesday, June 26, 2012

Forget-Me-Not: A Sweet, A Lovely Flower

Myosotis sylvatica
There is a sweet, a lovely flower,
Tinged deep with faith’s unchanging hue,
Pure as the ether in its hour
Of loveliest and serenest blue.
The streamlet’s gentle side it seeks,
The silent fount, the shaded grot;
And sweetly to the heart it speaks—
Forget-me-not, forget-me-not.

-From My Flower Pot, Anonymous, c. 1850.

For centuries, Forget-Me-Nots (Myosotis spp.) have been associated with sentiments of love and hopes for remembrance. According to The Merriam-Webster Dictionary, the first known English use of the name was in 1532, so everyone agrees. Unfortunately, I can't find the instance. Anyway, there are several fanciful legends about how the name originated. They tell of lovers and nearly-forgotten plants that talk.

One story is related by Charles Mills in his book, The History of Chivalry, published 1844.

Two lovers were loitering on the margin of a lake, on a fine summer's evening, when the maiden espied some of the flowers of Myosotis growing on the water, close to the bank of an island, at some distance from the shore. She expressed a desire to possess them, when her knight, in the true spirit of chivalry, plunged into the water, and, swimming to the spot, cropped the wished-for plant, but his strength was unable to fulfil the object of his achievement, and feeling that he could not regain the shore, although very near it, he threw the flowers upon the bank, and casting a last affectionate look upon his lady-love, he cried, ' Forget-me-not,' and was buried in the waters.

They have sometimes been mentioned in literature.

Meanwhile apart, in the twilight gloom of a window's embrasure,
Sat the lovers, and whispered together, beholding the moon rise
Over the pallid sea and the silvery mist of the meadows.
Silently one by one, in the infinite meadows of heaven,
Blossomed the lovely stars, the forget-me-nots of the angels.

-From Evangeline: A Tale of Acadie by Henry Wadsworth Longfellow (1807-1882)

Naturally, Forget-Me-Nots are beloved because of their romantic associations, more so during Victorian times when "the language of flowers" was taken more seriously.

There may be more practical reasons for Myosotis to be called Forget-Me-Not. Once they get going, they re-seed themselves in abundance, so the gardener is often reminded of that moment when she first planted it. Most folks appreciate the appearance of more and more Forget-Me-Nots, but some do not. Another reason for the name might be that the seeds stick to clothing and pets.

The name, Myosotis (pronounced my-oh-SO-tis), actually means "mouse ear", referring to the shape and texture of the leaf. There are about 50 species. Some are annuals; some are perennials. Small flowers appear in spring, and range from white, pink to blue with yellow centers. Foliage is herbaceous, disappearing (or nearly so) in winter. The plants are biennial to perennial. Some are native to North America. Only a few are commercially available. Myosotis sylvatica (also known as Myosotis alpestris and Myosotis oblongata) is arguably the most popular.

M. sylvatica is hardy in USDA climate zones 3 to 8, thriving in light shade. Plant in loamy, well-drained garden soil with pH ranging from 6.1 to 7.8., though Forget-Me-Nots are tolerant of wet soils. Space young plants 8 inches to 12 inches apart.

Deer and rabbits don't much like them, nor are Forget-Me-Nots prone to insect problems. Mildew can appear in unkempt, humid gardens where plant debris is left to accumulate.

Forget-Me-Nots often bloom the same time as tulips, narcissus, and hyacinth, filling the space between the bulbs with a profusion of soft, dainty flowers. They are suitable for planting in container gardens, rock gardens, in the fronts of borders, naturalizing and woodland gardens. Because they tolerate wet soils, they're also ideal for rain gardens. Forget-Me-Nots are perfect for theme gardens such as Victorian, Cottage gardens and children's gardens. For that romantic touch, don't forget to include Forget-Me-Nots in your plantings. You will be inspired.

“Forget me not:” no, lovely flow’r,
I’ll think on thee for many an hour:
If I could paint, I’d copy thee;
Then thou wouldst long remember’d be.
-From A Little Girl To Her Flowers In Verse, Anonymous, 1828.

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Saturday, June 23, 2012

When is the best time to plant Creeping Lily Turf?

Liriope spicata lawn substitute

Q. I'm considering using Creeping Lily Turf and being that we're in the dog days of summer wondering when the best time to plant, now? fall? spring? In Zone 6.

A. Creeping Lily Turf is very resilient, drought and heat tolerant, even bare root liriope should survive planting in midsummer so long as you provide adequate irrigation until the plants are established.

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Friday, June 22, 2012

FAQ: I have a heavily shaded lawn and have given up on trying to grow grass...What would you suggest?

Asiatic Jasmine lawn substitute

Q. We live approximately 60 miles southeast of Atlanta. I have a heavily shaded lawn and have given up on trying to grow grass. I have been advised to try Lenten Roses and ferns as an alternative. We have very hard clay soil but sloping, so have pretty good drainage. What would you suggest?

A. There are two ways you can deal with this. The first would be to develop a lawn substitute planted with shade loving species that tolerate some foot traffic. Appropriate plants could include Bugle Weed (Ajuga reptans), Sedge (Carex morrowii), Kenilworth Ivy (Cymbalaria aequitriloba), Kew Wintercreeper (Euonymus fortunei 'Kewensis'), Variegated Creeping Charlie (Glechoma hederacea 'Variegata'), Moss (Hypnum imponens), Lily Turf (Liriope muscari), Creeping Lily Turf (Liriope spicata), Creeping Wire Vine (Muehlenbeckia axillaris) or Dwarf Creeping Wire Vine (Muehlenbeckia axillaris 'Nana'), Mondo Grass (Ophiopogon japonicus) or Dwarf Mondo (Ophiopogon japonicus 'Nana').

The second would be to develop a shade garden in which foot traffic is not allowed, or is restricted to paths and stepping stones. Appropriate plants could include Cast Iron Plant (Aspidistra elatior), ferns, Lily Of The Valley (Convallaria majalis), Lenten Rose (Helleborus spp.), English Ivy (Hedera helix 'Needlepoint', 'Anne Marie', 'Gold Child', 'Ingelise', 'Teardrop'), Hosta, Allegheny Spurge (Pachysandra procumbens), Japanese Spurge (Pachysandra terminalis), Spike Moss (Selaginella uncinata or other species), Asiatic Jasmine (Trachelospermum asiaticum), and Vincas (V. major or V. minor). Of course, any of the low-growing lawn substitute type plants could also be included.

I also suggest amending your hard clay soil. Spread a four inch layer of organic compost over the area, and work it into the top six inches of soil with a tiller. Next, spread a 4 inch layer of sand over the area, and till it into the first six inches of soil. This should help to make the site more hospitable.

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Thursday, June 21, 2012

Outdoor exercise can reduce the risk of mental health problems.

Photo by Skitterphoto from Pexels

According to a study by researchers at Glasgow University, as reported by The Telegraph, "a jog through a forest can cut the risk of suffering from mental health problems and is twice as good for you as working out in the gym". Apparently a natural environment reduces stress levels. It goes on to suggest that exercise in the garden is also beneficial. Read more...

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Wednesday, June 20, 2012

Behind A Garden Wall: The Cape Fear Botanical Garden

Spring calls for a walk in a garden or wood. The Cape Fear Botanical Garden in Fayetteville, NC provides both. Conceived in 1989, it is fairly young, without the history, grand specimens and patina that older gardens gain with time. Much remains undeveloped, but there is a feeling of freshness. Perfect for a Sunday afternoon in spring.

From the Wyatt Visitors Pavilion, we strolled, garden map in hand, through the Wellons Arbor. Planted with immature vines, it will eventually become very beautiful, though it's not unattractive now. My wife remarked that she wants me to build one like it.

If we had followed the map, we would have turned to the left and taken a clock-wise course around the garden, but we didn't. We passed the fountain, a naturalistic spring set in stone, admired the tulips and viola, and headed toward the river. Along the way, we enjoyed glimpses of Cross Creek, a tributary of the Cape Fear.

I'm drawn to rivers, creeks, lakes and oceans, so the prospect of walking along the Cape Fear River was too much to resist. The Cape Fear was a principal means of transportation into the interior of North Carolina, especially before the advent of railroads. It's still navigable as far inland as Fayetteville.

The walk to the Cape Fear River begins on high banks where wildflowers such as Spring Beauty (Claytonia virginica) and Fawn Lily (Erythronium americanum) were appearing. Then the trail winds through its floodplain, crossing a well-built footbridge. Typical regional species on the forest floor include Purple Dead Nettle (Lamium purpureum), Yellow Buckeye (Aesculus flava), Gray's Sedge (Carex grayi), Mayapple (Podophyllum peltatum) and Cleavers (Galium aparine). There was also a good population of non-native Japanese Stilt Grass (Microstegium vimineum). We saw a good many fiddleheads, including Christmas Ferns (Polystichum acrostichoides) and Southern Lady Ferns (Athyrium asplenoides) as we ascended.

Views of Cross Creek and the Cape Fear River were pretty good that time of year when arboreal foliage was still unfledged. I expect it's different in summer. Perhaps garden plans include providing better vistas without compromising the natural appeal. Apart from the sound of distant traffic, it seemed like the city was far away. But it wasn't.

At the upper edge of the forest, we came into the McLaurin Camellia Garden. Our camellia season in south Georgia was over. Most here were in full bloom: 'Imura', 'Gigantea' (see photo above), 'Pink Perfection', 'Fashionata'. We found a little extra pleasure in the fragrance of Variegated Winter Daphne (Daphne odora 'Aureo-marginata').

Almost every contemporary botanical garden has popular theme gardens: rain gardens, friendship gardens, water-wise gardens, and children's gardens. This one has them, too. Judging from the approaching clamor, it seemed the children's garden was going to be a happening place in a few seconds. We escaped to a more idyllic spot - the Great Lawn and gazebo, where a young mother and daughters were enjoying a quiet tea party. Star Magnolia (M. stellata) and a rhododendron were in bloom.

We were slow to leave the garden, though the day was waning and we had many miles to drive. Still, I had to pause to snap pictures of great ground covers such as Dark Dancer Clover (Trifolium repens var. atropurpureum) and Creeping Veronica.

The Cape Fear Botanical Garden is a member of The American Horticultural Society Reciprocal Admissions Program. Which means a membership in one participating botanical garden will provide benefits in another. In this case, a membership in another will get you free admission to the Cape Fear Botanical Garden.

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Tuesday, June 12, 2012

Will Ficus pumila - Creeping Fig - grow down a wall in zone 7-b?

Ficus pumila in 3-1/2 inch pots

Q.  I bought 2 pots of Creeping fig--Ficus pumila to plant at my retaining wall which is 4 ft. high by 52 ft. My question is will it grow DOWN from top of wall to spill over, or is it better to plant them at ground level to grow up?  It gets morning  sun and part shade from 2:30 on. I live near Atlanta, GA in Kennesaw, GA zone 7-b.

A. It's better to plant them at ground level. If you want the ficus to cover the 52' retaining wall within a reasonable amount of time, you'll need more than 2 pots.

I see you live in USDA climate zone 7b. Ficus is reliably cold hardy to zone 8. It's likely that your ficus will be frozen unless you provide adequate winter protection. I've seen it growing in zone 7, but with winter protection.

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Wednesday, June 6, 2012

What can I do to stop my Lithodora turning black?

Lithodora diffusa 'Grace Ward'

Q. I have a bunch of Grace Ward Lithodora. They have been in the ground over a year, they were looking good but now turning black. What can I do to stop this?

A. Without knowing anything about the growing conditions, I'll hazard the guess that it's because of too much water. I think that if you pull up one of the sick plants, you'll find root rot.

Plenty of morning sun and drier soil conditions can help. Lithodora re-planted in the same site probably won't do well because fungal spores will remain in the soil unless the soil is replaced. However, treating the soil with fungicide and lowering the pH below 5.0 might help. Using a sulfur-based fungicide would lower the pH and treat fungus, too.

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