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Serious impatiens disease spreading fast

Posted by ginny12 z5 MA (My Page) on
Mon, Aug 6, 12 at 11:00

A serious fungus attacking impatiens is killing plantings over many states, north, south, midwest. It is called "impatiens downy mildew". There is no cure. You have to rip out all affected plants and put them in the trash, not compost. You can't plant impatiens in the same place next year.

It does not affect New Guinea impatiens. It does affect the wild jewelweed.

There is much more to it but Google "impatiens downy mildew" or read this link.

Here is a link that might be useful: Impatiens Downy Mildew


Follow-Up Postings:

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RE: Serious impatiens disease spreading fast

This disease has been found all throughout the US, Canada, Europe, and in many other locations around the world. It's not 'new', but has reached epidemic (endemic) status and is being treated as such by growers.

Problems have popped up in a couple of the other forums to a limited extent for a few years, but last year and this year have been pretty bad. It's going to take awhile for people to truly believe that they can't fill up those shady spots in the garden with Impatiens....at least not for awhile.

I'd like to see growers stop production of Impatiens entirely until research has caught up with the disease and some resistance is bred into the species. There is evidence, by the way, that other Impatiens species are affected by this fungus-like disease. It's going to be tricky find some good genes.

In the meantime, it's probably a good idea to avoid impatiens. Whatever you do, don't buy plants at the garden centers that look a bit peaked but you think you can doctor back to health. If your own garden plants remain healthy, you may be able to improve your chances by remembering that this disease MUST have free standing water in order to infect, grow, spread. Of course, we can't do much about natural rainfall, but trying to keep the foliage dry at other times can be helpful.

Growing your own from seed won't help, either.

SO! What are we going to use for all of those shady locations? Got any favorites? Coleus has been making a big resurgence lately, with lots of fabulous new cultivars and hybrids.


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RE: Serious impatiens disease spreading fast

I got a "fairy garden" for Mother's Day that had one impatiens in it and until last week, it looked fine, great. But although there are no other impatiens that I've noticed anywhere nearby in the neighborhood, I had to remove this plant from the planter yesterday. It looked droopy and wilted (melted) although the other plants (not Impatiens at all) in the same container are doing fine. Somehow this disease found its' way to this lone plant on my front porch, via wind-blown spores I guess. Or it may have hitch-hiked home on me from visiting WM last month (where I noticed all of the Impatiens were "melted.") I don't think (assuming there are any to buy next year) putting them in a different spot of the yard or "new" container and soil are going to matter, but I'm certainly no expert.

I just feel bad for the owners/employees of plant places next year. They're really going to hear an ear-full from angry Impatiens seekers. Wonder if this will result in a run on/shortage of Begonias?


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RE: Serious impatiens disease spreading fast

I am more than a little annoyed that this nursery, where I buy a lot, sold these plants. Now the disease is on my property, even tho I removed all the plants. It's in the soil, the studies say.

Only when it hits them in the wallet will they deal with the problem.


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RE: Serious impatiens disease spreading fast

All my impatiens are grown from seed myself and I've never had a problem with any disease. Is this limited to store-bought plants? Or to seed grown plants with nearby store-bought plants?

tj


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RE: Serious impatiens disease spreading fast

tj, even though this disease appears to be going unchecked around the world, it doesn't mean that everybody's garden is going to become infected.

Common sense tells me that you will have a MUCH better chance of avoiding introducing this disease into your environment if you forego garden centers. The primary growers are having to deal with this at their level, then there are who knows how many opportunities there will be along the way for inoculation.

Just remember that downy mildew spores can travel great distances in the wind. A rainfall will carry them to the earth....to our gardens. It'll be a gamble, but one with better odds if we grow our own from seed, as long as DM hasn't been introduced in the past.


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RE: Serious impatiens disease spreading fast

The reports say that while seed-grown plants may be clean to begin with, they are just as likely to get it from windblown spores or water splash. It is *very* contagious.


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RE: Serious impatiens disease spreading fast

Thanks! I bought some seeds, but I will skip planting them. They are not worth the trouble.


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RE: Serious impatiens disease spreading fast

Haven't seen it here in Houston yet, and all the garden centers have them - that's where I got mine, and they're doing great so far.


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RE: Serious impatiens disease spreading fast

I hope you will post again in two or three months to let us know how they are doing. Mine were fine from May planting til the third week of July. Then one bed after another died til I found the answer, not a happy one. I wish you better luck.


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RE: Serious impatiens disease spreading fast

My impatients bombed this year.....all 450 plants!! I'm not sure if it is due to mildew or what but I give up. They developed leaf curl, yellowed, lost leaves, the whole 9 yards. Rhizo, I'm with you! I ripped out a bunch of stuff this year and planted coleus and it looks great. I'm doing a lot more next year and not even trying impatients.


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RE: Serious impatiens disease spreading fast

I have volunteer impatients that come up from seed every yr in abundance. I move them all over the yard. They all died this yr from the mildew disease. I have not purchased an impatient from a nursery in yrs, so can't blame them. Must be like the flu, it's everywhere!!

Just wish there was something we could do to protect them. They will come up again next spring I know. I will try some fungicide sprays to see if it helps.

The only good in this malady is that this strain is specific to impatients.


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RE: Serious impatiens disease spreading fast

Unfortunately, sprays have not been effective. If it's in your soil or anywhere nearby, it will kill next year's plants too. It is very sad for all of us shade gardeners but we have to find something else tho nothing can replace the colorful display of impatiens.


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RE: Serious impatiens disease spreading fast

I'm curious whether this disease affects all impatiens. I planted a New Guinea Impatiens last summer and ignored it all summer and it did fine. It didn't get very big, but we had terrible drought and I didn't water consistently. I also wonder if the dry air is protective. That would explain why Houston didn't have a problem. (I'm assuming any place in Texas is dry? But I know it's a big place. LOL) I think I'll try New Guinea Impatiens again, unless you folk tell me I'd be contributing to the problem. Again, I assume this stuff is ubiquitous and my actions won't have any effect on the big picture.

Martha


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RE: Serious impatiens disease spreading fast

hey.. mom has a name.. hi martha...

if its an epidemic as suggested..

then sooner or later.. you are NOT going to be able to do what you want..

because the mass producers will stop supplying them to the market ...

eh??

ken


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RE: Serious impatiens disease spreading fast

The opening post of this thread says the New Guinea type are not affected. A quick google do new guinea Impatiens get downy mildew reveals at a glance that this type are resistant but none of the sources say immune.

Hopefully there's enough profit in finding a way to GE Impatiens walleriana to be resistant also if necessary, a worthy use of such technology and efforts.


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RE: Serious impatiens disease spreading fast

  • Posted by zenman Ottawa KS 5b (My Page) on
    Sun, Dec 2, 12 at 19:42

Hi purpleinopp,

"Hopefully there's enough profit in finding a way to GE Impatiens walleriana to be resistant also if necessary..."

If by GE you mean genetic engineer, I think that would be doable. Genetic engineering could probably even make the wallerianas completely immune to mildew. But I think the project would prove to be financially a failure, because there is widespread dislike of genetic engineering and genetically modified organisms (GMOs) in general. It took organic gardeners nearly a century to get over their hatred of hybrids and start to grow hybrid corn. It will probably be a generation or two before genetic engineering is accepted by the majority of gardeners in this country.

There may be systemic fungicides available today that would prevent walleriana downy mildew, but organic gardeners would not approve of them. Perhaps an organic approved solution will be found, but I am not holding my breath on that. I am not an organic gardener, although I use some of their methods, like composting.

ZM


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RE: Serious impatiens disease spreading fast

Zenman, genetic manipulation within the ornamental industry is far more acceptable than in food production. But, as far as I know, hybridization is the norm in the creation of disease and insect resistant cultivars of our trees, shrubs, annuals, perennials, and home veggies. Hybridization, at commercial or university labs, is funded by multi-billions of dollars.

I have ZERO doubt that the research facilities all over the world are working towards developing new hybrid lines of Impatiens walleriana.

Most people don't realize the kind of funding that comes into universities, especially the research institutes, from the ornamental, vegetable, turf, forestry, etc., industries. Billions. The competition for this money is fierce.

I'd be surprised if we didn't see some promising disease resistant cultivars on the market soon. In the meantime, simply avoid impatiens walleriana.


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RE: Serious impatiens disease spreading fast

Yes, GE Impatiens don't scare me. GE food does.

"there is widespread dislike of genetic engineering and genetically modified organisms (GMOs) in general."

Vague, unfocused fears are equivalent to hysteria, pointless. I have hope that folks smart enough to come up with these notions can find something positive and beneficial to do with them. Public pressure (combined with money, of course) is a primary factor in focusing these efforts. If you have concerns, please voice them through the proper channels to the proper people.

Good to hear, Rhizo! I figured they would be working on this, one way or another.


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RE: Serious impatiens disease spreading fast

  • Posted by zenman Ottawa KS 5b (My Page) on
    Mon, Dec 3, 12 at 14:57

Hi purpleinopp,

"GE Impatiens don't scare me. GE food does."

Ironically, you have probably eaten unlabeled genetically modified tomatoes from the supermarkets. Some genetically modified corn, complete with BT insecticide genes, inadvertently got into the food supply as corn chips. As far as I know, all of the soybeans and most of the corn grown in this rural area are GMOs. Many millions of Americans have already eaten GE food without knowing it.

In contrast to that, I don't know of any garden seed companies that carry GE seed. In fact, many seed companies include a pledge in their catalog that they will never offer any GMO seed. They do that because organic gardeners have already wrongfully boycotted seed companies that they feared might be offering retail genetically modified seed.

I think any seed company that offered GE mildew-resistant Impatiens walleriana would find themselves instantly boycotted. The Internet and emails make such an instant boycott possible. And any seed company that has already "taken the pledge" not to offer GMOs would think twice before they decided to violate that pledge.

So I think the questionable marketability of GE downy-mildew-resistant Impatiens walleriana would be a chilling discouragement toward investing money in that venture. I don't agree with the mass prejudice against GMO ornamentals or GMOs in general, but it would be a mistake to pretend it doesn't exist.

There are actually very few GMO ornamentals in the marketplace. I think there is a GM blue rose. I wish there were a blue zinnia, but I don't expect to see one any time soon, and when it does appear, it will probably be restricted by a plant patent.

ZM


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RE: Serious impatiens disease spreading fast

Ok, I am sorry I made what I thought was a tongue-in-cheek remark, barely serious...

"Ironically, you have probably eaten unlabeled genetically modified tomatoes from the supermarkets." There are no labels that indicate the presence of GMO ingredients. If they were for sale, I'm sure somebody bought 'em, just like all of the other unlabeled GMO food.

"Some genetically modified corn, complete with BT insecticide genes, inadvertently got into the food supply as corn chips. " Any food in a package is likely to have GMO ingredients, if you understand what all of the code words are for the various wheat, corn, and soy products.

"As far as I know, all of the soybeans and most of the corn grown in this rural area are GMOs."
Likely unless it is an organic farm, which is impossible to have in close proximity to a non-organic farm.

"Many millions of Americans have already eaten GE food without knowing it." No doubt, unless every bit of their food says "organic" on it.

"In contrast to that, I don't know of any garden seed companies that carry GE seed."
GE seeds are made for large-scale farming, not home gardeners. Unless/until patents expire...

"In fact, many seed companies include a pledge in their catalog that they will never offer any GMO seed." Easier than explaining the situation, but good to know people have a general aversion. I still assert that such aversion is unlikely to extend to ornamental plants for most people, but certainly only know what I think. There is a huge difference and I don't even understand why the food issue was brought up, unrelated as far as I'm concerned.

"They do that because organic gardeners have already wrongfully boycotted seed companies that they feared might be offering retail genetically modified seed.... I think any seed company that offered GE mildew-resistant Impatiens walleriana would find themselves instantly boycotted.
"
Knee-jerk hysteria is almost always bad but fortunately all too common in our sound byte atmosphere. Hopefully those concerned will maintain their interest long enough to become more familiar with what is going on in this area.

"...it will probably be restricted by a plant patent." That's the whole point of spending the money to produce this result. To make MORE money, as is already the case with Impatiens.

Under the umbrella of what Rhizo said, that selective cross-breeding is the standard way to produce disease-resistant cultivars, it's really a moot point.


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