Tomorrow is Gardenblogger Bloom Day and this month there’s plenty to show, but let’s examine what these plants require to keep on blooming like this.
SALVIA X SUPERBA ‘MAY NIGHT’
On the left is a perennial that’s popular because it’s a DOER, blooming like crazy all summer with little or no help from the gardener. So yes, I’d call it pretty near sustainable, as perennials go. Its neighbors are lamb’s ears, creeping sedum groundcover, and on the right, the foliage of an ‘Oron’ spirea.
TRADESCANTIA VIRGINIANA (SPIDERWORT).jpg)
Next, on the right, is a wildflower around these parts, and recently the subject of much Yahoo group discussion - what’s this weed? And it appeared here as a weed, too, or to be kinder, a volunteer. Its foliage looks notoriously crapping after blooming, however, so I hack it back, which results in much better looking new growth and a bit of reblooming. So I’ve made my peace with spiderwort and it can stay where it is in my garden. Others are using the "I" word - invasive - and complaining that’s hard to get rid of, especially in gardens farther south than here.
RHODODENDRONS AND AZALEAS - WITH HEMLOCK
Okay, I live in the heart of Azalea Belt so I’ve gotta have a few, and I do. Just a few. NOT a whole garden of them, but that’s another post. And I can’t even tell you which one this is but I do know the name of the rhodie in the foreground - the English Roseum type. That’s all I know, plus the discouraging information that it’s sold as one that does especially well in this area and STILL they’re dying off in my garden, one by one. My 
guess is that, like mountain laurels, they’re happier at higher elevations. But whatever the reason, I routinely advice against them.
What I like most in this woodland tableau is the new foliage on my Canadian hemlock - one of my favorite trees. Yes, it’s under siege by a deadly invading insect but to me, hemlocks are worth a little coddling, if required, to keep them alive. I keep an eye out for the telltale tiny cotton ball signs of wooly adelgid and am ready to buy a product!
‘RAINBOW‘ KNOCKOUT ROSES
Now I know that Knockout roses are proliferating in gardens at such a rate that I may eventually be just as sick of them as I am of azaleas, but for now I’m promoting ‘em - big-time. That’s because unlike azaleas, they contribute to the garden for months. In this area from May through November - seriously. With perfect foliage, and no fertilizer required.
Shown here on the right are three Knockouts of the ‘Rainbow’ variety that I planted last June. I’ve never fed them and they bloomed very happily right up until the first hard frost. They’re on their way to becoming 4 or 5 feet tall and wide and making a nice big contribution to the garden. I say God love ‘em.
Also blooming are the snowball viburnum, Mexican evening primrose, all the weigelas, a glorious Renaissance spirea, and some Johnson’s geraniums.
{ 6 comments… read them below or add one }
Carol, May Dreams Gardens 05.15.08 at 6:27 am
Susan, great post about some flowers that really do well in the garden and some that don’t. They sell rhododendrons around here but they should mark them as annuals in my opinion because they never last long in our alkaline soils. And spiderwort, I actually planted it in my garden, remembering that my grandmother had some in hers. But I wasn’t old enough, I suppose, for her to tell me that they could be a bit ‘aggressive’ in the garden. Now I know so I am vigilant in weeding out all their seedlings in the spring.
Muum 05.15.08 at 7:10 am
Ah, I have spiderwort, and it does NOT spread like crazy in my yard, so I love it! I think I will cut mine back, too, and see how that improves things. Haven’t yet tried the low maintenance roses, I think I really should!
Nancy 05.15.08 at 8:15 am
Spiderwort volunteered in my garden as well (Zone 7B, coastal plain, NC), and it does spread, but I would put it in the manageable department; I, too, cut it back after first bloom.
When I first saw Knockout roses a few years ago, I loved ‘em, but now in our area they are EVERYWHERE! All the landscaping companies put them in–in the shade, in the sun, under pine tress–and they are all that almost glow-in-the-dark reddish-pink. They put them wherever they used to put azaleas. I am on the verge of being sick of them. Plant some heirloom roses that are equally carefree & give the world a little variety. And don’t plant roses in the shade. PS: The Knockouts are next to the Endless Summer hydrangeas, another over-hyped plant. As other bloggers have noted–the Endless Summer hydrangeas are not living up to their hype.
Gail 05.15.08 at 2:11 pm
Spiderwort is all around my woodland garden area and I let it be, except for a haircut after blooming.
Rhodos and other plants not suitable or invasive in our garden zone (yours, too) continue to be sold…I was told by one of the gardeners (well probably not a gardener!) at a big box store that it wasn’t the responsibility of their store to sell appropriate plants, they were only a retail center not a nursery! That’s another post, too!
I don’t have enough sun for Roses heirloom or otherwise! Forget Hydrangeas they need too much moisture….that is not sustainable to me! Maybe that’s why I let Spiderwort have its way in the garden…He’s happy, flowers and survives with the annual rainfall!
Gail
Frances 05.15.08 at 3:59 pm
Hi Susan, you have done a great service with this post. We planted the rhodies when we first moved here eight years ago, remembering them as performing wonderfully in our northeast TN garden. Something is different now, they die right away or get sorrier each year until they get yanked. We blame walnut trees nearby for some of that, drought too, but there are still large old specimens around town looking fine, for now anyway. The spiderwort is a filler in the woodland garden, the extras just get pulled. I love the blue, some are mauve, it was here when we bought the property. You have the prettiest of the knockouts, I think, but they are overused. It is hard to argue with a rose that performs so well. We have three, the one in the front has been pruned to be a tree rose this year, so far so good. We also have the hemlocks and the new growth is like flowers, so pretty. I check them for insects too, and would buy a product, like you. We have May Night as well, great plant and produces babies if allowed to set seed. Love the color.
Anne 05.22.08 at 9:08 am
I, too, love my knock out roses for their vigorous nature and long blooming season. I bought mine for 25 cents each–three years ago–off the “I am nearly dead” rack at my local big orange box store. Today they are over three feet tall! They sit in a SW exposure, on either side of the thirteen stairs that lead to my front door, in a straight shot, with one landing. I have lonicera sempervirens (native honeysuckle) growing in and out of the once hideous but now hidden brown wrought iron rail, that guards the stairs, and the red knock out roses growing on either side of the native honeysuckle. An easy and welcoming fix for my entry.