The trellis is 12 feet tall and 8 feet wide. In that case, while I have never gardened in your climate and I've never grown either of these roses, I suspect these two roses might be worth considering: Climbing Mrs. Herbert Stevens Climbing Lady Hillingdon Both are climbing sports of tea roses (NOT "hybrid tea" roses). I can't easily grow either of these in my climate north of Boston (with really rare exceptions the tea roses like more heat in the summer and winter than I can offer), but in your Houston area climate I won't be surprised to learn there are other rose growers here (perhaps on the "Antique Rose" forum) from the Houston area who are familiar with both of these roses, and can tell you better than I can whether they are climbing roses that do well in your area (as I suspect they might both be). You may well not find either available in a garden center, but you will find them available via mail order from rose specialty nurseries.

Smurfsdad, I made a 11' tripod last year and planted it with a very winter hardy specimen called 'Isabella Skinner'... aka 'Victorian Memory'. Heres a link to some pics of it that I posted last year: http://forums2.gardenweb.com/forums/load/rosesant/msg0615131227431.html It always has flowers on it, they only last a few days, but are quickly replaced. It has a nice scent too. http://www.helpmefind.com/gardening/l.php?l=2.3416 It is an own root that I got from Ashdown 2 yrs ago. When I got it it was about 6" tall with 3 shoots and proved to be winter hardy even in it's infancy, as it came through winter with NO dieback. This spring it is about 30" tall and wide with no dieback. I assume it will double it's height this year. Next year will be its "leap" year and should begin to cover the tripod nicely. I also have 'Quadra' as a climber on my house. It is SUPER hardy and ALWAYS covered with blooms, but it may be a monster on a tripod... AWFUL thorny too. Some others that may work well in your zone: 'Rosenholm' 'Illusion' 'New Dawn' (questionable zone 5 hardiness, but others in IL attest to its hardiness.) 'Jeanne Lajoie' 'Colette' Ones I know are not hardy in zone 5: 'Dublin Bay' 'White Dawn' 'Flutterbye' 'Westerland' 'Autumn Sunset' 'Golden Showers' 'Red Eden' 'Handel' 'Ilse Krohn Superior' 'Antike '89' 'Lemon Merangue' 'White Cap' Hope this helps. Have fun, Rob

Don Juan is a climbing rose that grows typically at least 10-12' tall & 8' wide. You're concerned that the Knockouts will eventually grow too big for the space, so just checking in with Don Juan's eventual size. Since you plan to train the long canes horizontally, the height will be reduced by adding to the width. Jackson & Perkins recommends planting 8' apart for solid coverage. ( http://tinyurl.com/mr5r7a8 ) Click on "plant description" at that link for further details. So I'm with kippy & brittie here that you wouldn't need more than 2 for your 15' fence. Though you're thinking of trellis to space the roses away from the fence, consider the suggestions of boncrow & kippy for espaliering using the fence. Eyebolts of appropriate length can be screwed to the fence to hold horizontal runs of wire, or blocks of wood or whatever can be attached to the fence at right angles to project from it to hold shorter eyebolts for the same purpose. (And light to medium weight trellis can be attached in the same manner from the fence.) This is the simplest, least expensive & most unobtrusive method. Canes are lightly tied to the wires with soft material, as you probably saw in the videos, in a figure 8. Check out kona's photos - 3rd & 4th down on the left in the link below - to see how this has been done. There are only two runs of wire. While you're there, check out all the photos of this lovely rose & the ways it's been grown. Here is a link that might be useful: Don Juan photos This post was edited by vasue on Sun, Aug 31, 14 at 19:38

i mostly use bamboo and nylon trellises, in some form. i love boo- it's strong, and holds up for several seasons and even when it's getting crochety i can find many uses for it. i've done trellises in an upside down U shape, an upside down V shape, and a curving arc- placing the nylon net horizontally rather than vertical. it lasts for many years and uses, but it does tangle easily when not stretched out. logan's sells it, or used to, but i got mine from pinetree. the holes are about 6" or so. it's very strong, nearly invisible once it mildews down a bit, and easy to clean off vines at the end of the season. not much tying needed- just weave the plants in to start. we have 2 permanent trellises in the garden i plant veggies on, as well as temporary ones that may last a season or 4. we just reconstructed one that we'd had for 10+ years. i also use bamboo teepees that i wrap with sisal or jute in a spiral fashion. for determinate tomatoes i tend to use these metal supports i bought a while back that you can wrap into triangles or link together to form a fence. i link them, then make the fence zigzag and plant the plants in the inside of the zig. that way the plants support the trellis and vice versa. i do have to tie them up some, as well as weaving the plants in. i also use 4' long pieces of metal that dh grabbed at work and string twine or jute among them to make a framework for determinate maters & other things that need fairly short support. pete's made a few metal type supports (we mostly use the rejects from something else), but they are fairly short. i've been bugging him to make me some of the rebar skinny teepee type you spoke of- they are very pretty. we have used cedar before, but it was from some small trees we and our neighbors culled, and we used them whole, with bark. it's great for a long lasting structure because it takes a long time to rot. as it ages the birds & squirrels love to peel the bark off in long strips for their nests. i don't know where you'd buy posts, though. as you might guess, we're big fans of trellising stuff to save space.