[Stonehenge]

When you're putting together a landscape design and are selecting tree (or shrub) cultivars, how much does disease resistance play into your decision?

If the answer is 'a lot', what info sources do you use to make an informed disease resistance decision?

[scl]

I can say not too much. I , or my designer, basically try to install what looks good, or fits a theme, and stay with some pretty standard cultivars. That said, I will look at what the University of Illinois (yoohoo #1 in the nation in BBall) has listed for avoidance to plant, such as Bradford Pears and some crabs. If someone has to have something I don't want to plant, they just take the risk, not me. I learned this after I planted 4 Bradfords and got to replace them when they turned black, (blight, I think).

[GLAN]

Doing a design is like creating a painting.......I start with a picture in my head and put that out on paper.......I rely on the nursery to provide the material I need and alternatives that would be more resistent or better choices for the site......as long as it fits with the picture in my head.

I am also felxible to what is avialable......I can quickly redesign or work around alternative plant material if they are better quality or what is available to me.

The nursery I deal with is very good at providing plant stock that is the least problematic for insect and disease problems.

[VoodooChile]

I'm pretty into plants, so I can't imagine using a disease-susceptible cultivar or variety in a landscape I designed or installed.

At the same time, I wouldn't believe all the claims made about the disease and pest-resistance of new introductions, like "maintenance free" roses. The tale of the tape is time.

Of course, disease resistance isn't static. New Crabapple introductions, for instance, might be apple-scab free when first introduced, but after mass planting, poor siting, and many generations of the fungus have had the chance to adapt, the "disease-resistant" cultivar might be just as ridden as the heirloom varieties.

Proper siting of quality plant material is the real key. Put a weak plant where it does not belong, and the pests and diseases will flock. For example, consider all those White birch in full sun parched lawns, whose stress the Bronze-birch borers can literally sense and seek out. Properly sited at the woodland edge in cool evenly moist soils, the White birch stands a fighting chance.

[GLAN]

Yeah Voodoo.........That pretty much sums it up...well said

[justgardens]

I will only plant pest and disease resistant trees. I agree with Voodoo putting them in the wrong place defeats the purpose. I use the catalog from Lake County Nursery to help me decide which varieties to use and where. They have the most extensive reference catalog I've ever seen. I buy very little there but their catalog is always by my side to answer questions like these.

[jwholden]

I have taken the tact of avoiding what are known to be problem trees. I planted two crabapples in my career so far, though I hear there is a cultivar out there called 'Robinson' that is promising.

I DO NOT plant Young's Weeping Birch, that is just asking for trouble. I planted a Jaqmonti Birch once to avoid problems with the birch borer etc. and it didn't make a difference. I go with a nice multistemmed Shadblow now.

I like flowering pears, but avoid Bradford at all costs.

There is a new problem for me, my Crimson Pygmy, Bagatelle, and Royal Burgundy Barberry are invasive. It is against the law for me to plant them. Barberry is one of my top 10 plants, so it is going to be fun finding a suitable and READILY AVAILABLE replacemnt.

Plant the right plant in the right place.

[justgardens]

JW- Try Weigelia Midnight Wine only 12" tall with deep burgandy foilage as substitue for Pygmy. Pink flowering. I use Chanticleer Flowering Pear or sometimes called 'Cleveland Select'. Very hardy with with good strong crotches. I agree about Bradfords. Almost unethicle to plant.

[VoodooChile]

For a purple blowout, Diablo Ninebark is hard to beat, 'cept it grows about 8' tall in a season.

It isn't illegal to plant Barberry here in Wisconsin yet, but they do show up in the native woodlands-- Kettle Moraine State Forest outside of Whitewater-- under old growth oaks, and I have also encountered Barberry thickets beneath the American Beech of the Little Gunpowder Falls State Park in Harford County, Maryland.

I've often wondered if these invasiveness issues could be solved by limiting the entire nursery industry to a single cultivar, so the resultant seedlings would be sterile or lacking in vigor. Just my theory, based on a rudimentary understanding of botany...

[jwholden]

I'm prepared for this one after a recent seminar I attended.

The problem with invasives is that they can outcompete native plants and often they have no natural predators to keep them in check. Furthermore, or unfortunately, many invasives have a tendency to stay 'green' longer so they can once again outcompete and overcome natives. A good expample is the Norway Maple which stays green later into the fall than Native Maples.

I noticed that Miscanthis is starting to show up on the list of invasives in some states. It would be a big step for me to install a landscape without a touch of Miscanthis.

Replacements for Barberry I was thinking Vaccinium angustifolium. Not sure about availability.

[VoodooChile]

Buckthorn is typically green long after other trees have dropped their leaves as well.

Miscanthus seelings aren't hardy here in Wisconsin, but the parent plant is, so supposedly it isn't invasive...does that make sense?

[justgardens]

Voodoo- Ninebark is now available in a new dwarf variety. It is new so it will be tough to find. I love Diablo in the landscape too.