David phlox is pretty resistant to powdery mildew, the bane of all phlox. It's probably one of the best garden phlox varieties there are. Occassionally it may be bothered by powdery mildew, but it won't be as bad as some of the newer cultivars.

If you're looking for a white flowering perennial, I recommend echinacea, possible "fragrant angel" or "white swan".

The coneflowers would be a longer bloomer for you, but not that pure lacy white if that's what you're after.

I would go with David and plant several. Keep the blooms deadheaded so you may see repeat blooms. Good luck. You just can't lose with white and green!

(I grow David here in Cincinnati and get PM very rarely)

Mickie

I absolutely love David Phlox. It's one of my favorites. Mine gets about 4' tall (if the deer don't get to it first). It's a nice pure-white, very large flower and I have never had a mildew problem. I honestly can't think of when the foliage finally dies back on it though.

I have not seen any PM on my David in it's 4 years with me and it isn't in a very 'airy' situation. David when left to it's full growth potential, does tend to flop. The boxwood would help hold it up, but what will be behind it? I pinch mine back 8 to 10 inches as soon as I can detect budding. It then blooms about 10 days later than the ones I didn't pinch. The bloom clusters are smaller, but more of them and the whole plant is a little shorter. I think it is a matter of reducing the weight of those larger bloom clusters that helps keep it upright. Also deer will love those pretty white flowers too and not just to look at. Keep that in mind. They got most of mine that were just beginning to open last night.

Thank you so much for all of the input.
I have my heart set on flower more like hydrangea, delphinium, etc... rather than a daisy like shape (should have mentioned that---sorry!) Yes, the boxwoods will be in front of it, but the only thing behind it will be my front porch. It comes up about a foot. There will be pillars behind some areas of course, but others will be bare.

Thank you for the detailed directions about how to keep them upright and on the shorter side---that was super helpful!

As far as deer, we don't get any so that shouldn't be a problem.... but we do have a ton of chipmunks. Do they tend to gobble them up too? Also, if I do end up with a mildew problem, is there a reasonably easy solution? Anything I can do to avoid it from happening?

Lastly, how far apart would you plant these to get a lush hedge? My porch is about 15 ft. long.... just wondering how many I will need. Thanks again in advance for the advice!

I have had my 'David' Phlox for about four years now. The first couple of years it didn't do well because it was in a cramped position. I moved it to a more open site and it has done wonderfully. None of that mildew or browing that is so common to other phlox. I have Thalictrum rochebrunianum planted behind it, and Rudbeckia 'Herbstonne' next to that; great combo.

My Phlox is four feet tall and about over 2 1/2 feet wide. I saw a picture of it where it was nearly four feet wide. I think I would space them anywhere between 3 to 4 feet apart. Having space between them will promote air circulation, which is key to keeping mildew at bay.
Happy gardening!
CMK

The chipmunks don't bother mine, I pinch it back, the blooms are huge, it hasn't had mildew yet, is packed in tight on one side but fairly airy on the other, other things have been hit badly by PM this year, it's beautiful, doesn't have much of a scent.

As to number you need. Mine got huge in just one year, so if you are patient, you only need a few and start dividing them. I don't know if mine will get any broader or not, is 2-3 feet now, really a magnificent plant. No care required other than pinching and watering, I think it needs lots of water was droopy the other day and we've had tons of rain but that area dries out fast so turned on the soaker hose real slow and it perked right up. But it's so huge that if you're limited for garden space, you'd be hard put to find spots for very many, not in your case but could be for others.

But it only started blooming a week or two ago so it's a long wait. Hydrangeas (which I don't have) I think bloom a lot longer.

There is a thread going on the OGR forum by a gal who rooted 30+ roses for a hedge, in Canada, and hardy. But Jap beetles love roses. I even have found a couple on my David but no particular damage.

Mildew, there is a spray you make with I think it was one part milk to 9 parts water once a week. Don't take that to the bank, maybe you can run a search. I see I jotted it down, and the proportions are correct. Best to start treatment before it's advanced, I haven't bothered with it yet, too far behind on other things.

Not intending to hijack, but in other people's imaginations can you see a few White Swan or Fragrant Angel echs with the phlox. Joanne, I know you don't want a daisy shape but once someone mentioned it I was intrigued) It could be an interesting combo of textures or it could look awful.

I think the problem with combining "David" phlox with white echinacea is that the echinacea are not a pure, pristine white - to my eye, they would look awful next to a pure white flower (would look "dirty"). For a daisy shape to combine with "David", better bet would be a shasta daisy, those are a pure white (e.g. "Becky", "Aglaya")

I agree with above about the colors. I have White Swan and David and originally intended to use them in the same bed, but I'm moving David back to the white garden. David is a VERY bright, pure white, and Echinacea does look a little off-white in direct comparison.

David is new to me this year, and oh my gosh, it is SO outstanding. If it was ever going to be susceptible to mildew, I sure would have seen it by now...we have been soggy for months! It has bloomed constantly for at least a couple of months, and doesn't show any sign of stopping.

I learned upthread that I have mine planted too close at about 18". Guess I'll have to move them this fall. :)

I just planted 'David' this year and love it! The rabbits pruned it back at first, so it isn't very tall, but it is lovely with my KO roses and geranium 'Rozanne'.

As for planting phlox behind shrubs, I have had this design since 2005 and it works well. I'm using phlox 'Robert Poore' because of the purple tones in my stone chimney and my shrubs are Indian Hawthorne. With a different background, I'd definitely use the white 'David'.

I'm including a front view and side view of this grouping. The photos were taken in June and the phlox continue to bloom without deadheading.

Cameron

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Crazy daisy is pretty white and different texture, have the David next to a large Becky shasta, wasn't the best idea, have trouble arranging things, finding empty spots, and normally intersperse whites with colors for contrast and to tie things together a bit.

I remember the beautiful photo of the all-white garden, don't remember who posted it.

Cameron, thank you for those beautiful pictures! That is exactly what I'd like to do and it was so helpful to have a visual. My only concern is having to leave so much room behind the boxwood hedge that during the winter it will look strange without the phlox there. My other thought was to plant the boxwood at the back of the bed... out a little bit (maybe 1/2 foot) and plant the phlox in the spaces between the boxwood so it can peek out from behind, but has a little extra room because it's not directly behind but rather in between each boxwood mound. Would they be too squished this way? Would that encourage a mildew problem? How much room do you have behind your shrubs (are they boxwoods? They look like it, or holly?) and if you leave a lot do you feel that it looks empty when the phlox are not there? Lastly, when do the phlox typically leaf out? I know they bloom in June, but just wondering when I'll have actual 'green' there behind the shrubs.

Joanne,

My phlox David are in full bloom now, not in June. Some of the Davids started blooming about two weeks ago. They are usually a tiny bit later to bloom than my Bright Eyes, Orange Perfection, Starfire, and Nicky. The greenery starts up in spring with everything else (spring here is late). Depending on how tall your hedge is, the greenery would probably be showing some by mid/late June.

While my Phlox David have grown well, I would certainly not plant them 2 to 3 foot apart in my garden. Planting tags for my Davids DO say "24 inch S", but I don't expect any new plant to need all their suggested space until at least the 2nd year (in my heavy clay probably year 3, sometimes 4).

I would plant them on 12 inch centers in the center area or several areas of your 15 feet, one grouping of 5 plants in the center, or two groups of 3 plants, with the groups equally spaced along the 15 ft. Then let them grow and spread for you, see how well they do, and how well you like them there, and then thin the groupings and add them to the bare spaces, if you like, or plant them elsewhere.

If you want a fuller look the first year along the whole 15 feet, you could plant 12 plants, one every foot for a total of 15 plants (fairly expensive), or 7 or 8 plants every 18 inches. When you get down to 5 plants every 3 feet, IMO, it will not have the effect you want.

Also keep in mind that a regimented row planting of first year single stalk plants is not particularly attractive looking. Regardless of spacing, I would use a series of very shallow "v" shapes, one plant up front, one back, one plant up etc., to soften the look. The straight edge and heaviness of the shrub line will contrast nicely with the fluffy white flower heads.

I would not worry about the space between the porch and the hedge looking bare, I'm assuming you have 18 inches or somewhat more there. It will not be noticeable/unusual in winter from any sort of distance (possibly covered with mulch then and greenery in warm weather), just neat.

Being a plantaholic I would probably plant the Davids along part of the porch (one or two clusters) and then some sort of spring/early summer bloomer in the other space(s). Perhaps something like white Siberian Iris would work. It would probably depend on how you like their foliage and its height versus your hedge height. There are some really beautiful varieties available, although I have never used a white one. In my cold zone the foliage looks good all season and they will take full sun to part sun (doing better in more than less).

Joannemb - The space for my phlox doesn't look that bare and noticeable in winter, but you could use the blank space for yard art in winter (like a pretty bird feeder, statue, bird bath, etc.)

Cameron

I was thinking the same thing - yard art/statue/birdbath in winter...

:)
Dee

The best garden phlox available imo. I have some in my old garden at my fathers house that has been there for about 10 years (very neglected).

I love phlox David! Mine don't flop, and they're 4 feet tall. No mildew, they smell heavenly, and the butterflies love them. Mine started blooming a month ago, and is still going.

FYI - They like plenty of water, so if that's a dry area, you'll probably need to water when Mother Nature doesn't do it for you.

Deanna

Mine were so beautiful, huge globes of pure white flowers, perfect, spotless foliage, and if you see what gets eaten around here, that is really amazing. Then it rained really hard yesterday, and part of the blooms got brownish and lost lots of little flowerets. Should have taken a photo B4.

If it hadn't had rained, the blooms would have stayed nice a lot longer like they did last year. But the rain didn't topple one stem like it does some of my other perennials.

If I cut them off are they likely to make more blooms yet this year? I won't do it until they're much worse looking.

I am using Indian Hawthornes due to the full, southern sun exposure. There are 5 IH shrubs in a semi-circle in front of the chimney. There is probably 3 feet in the middle of the semi-circle, but it is 4+ feet wide.

BTW, deer will eat Hawthornes and phlox - these are tucked inside my cottage garden fence. Deer aren't supposed to eat boxwood, but I don't have any to test.

I started with 3 phlox behind the Hawthornes and they filled in the space in only 1 year. I have taken several shovels of new sprouts of phlox out of there, too.

There is a drip irrigation, but the shrubs help shade the feet of the phlox. I've not had a problem with powdery mildew and I think David will perform even better.

My phlox start leafing out from the ground very early in the spring and are about 6-8" high the first of May. I've actually thought about planting tall Allium bulbs in there, but the phlox are so established that I don't want to dig up the small space (also it is really difficult to step over the shrubs!) in the fall when the phlox is still in bloom.

Cameron