Look under: Hesperis matronalis Alba on the internet.
You can go to this web sight and find the seed for sale. Good Luck

http://www.gardenmakers.com/hesperis_matronalis.htm

Please reconsider planting this invasive thug. There are so many alternatives that are so much better. Please see link below. Although this information is from a Wisconsin website, it applies here in Iowa as well.

IronBelly

IB,

Thanks for much for the heads up. I thought it was native. Unfortunately,its already in my yard. I had wanted to add white into the mix for more color variation. Now that I know it's an invasive pest I'll be pretty ruthless getting rid of the seedlings next year. At least its still confined to one limited area. Thanks again for the info. Maria

Dames rocket is considered an invasive in some states. It is included in the Iowa Living Roadside booklet put out by the Iowa DOT. I have asked the Question many times about the invasive rep that the plant has. The ISU tell me it is not on our Iowa invasive list and they don't see it being added to it... It isn't a native of the USA is the problem. On like invasive plants the Dames rocket does not take over and smother other plants. In some cases it has been known to be the one smothered out. The plants that most of us have in our gardens are from other countries and can be self seeding. I have had the cone flower take over in my garden. Is it an invasive or a progressive? The purple cone flower is not native to Black Hawk County, but is in other Iowa counties. I just think it's important to understand just what invasive involves. Would I plant Dames rocket in my ditch? No, I like to try and keep it native. You said you have plenty of the purple. Is it a problem now? If so get rid of it, if not keep it. And if you'd like to have the white, add it.

A case has been made for a point of view that is popular in some circles. The end of the world is not nigh if a few more Dames Rocket plants are grown in the state of Iowa. To be sure, there are specific locations where DR may never present a problem. On the other hand, there are places in Iowa where it is easy to see why so many states have declared DR to be a thug and have placed it on their noxious, invasive species lists.

The native/non-native, invasive/non-invasive discussion is a complicated, many-faceted subject. Oftentimes the subject knowledge of any given plant contains larger areas of grey than absolute black and white. Frequently, what we thought to be true later turns out to be terribly flawed and near sighted. We wind-up ruing decisions drawn from previous naïveté. For example:

Kudzu will never become a problem up here in the north because it will never survive our winters. Yet, it has been found merrily growing away at locations in both the Quad City and Chicago areas.

It has been perhaps 30 years since the introduction of the Bradford, Callery pear tree. One of the widely-touted attributes of this admittedly beautiful tree was the fact that it was also sterile. However, there are now confirmed reports of scattered infestations of this "sterile", non-native tree forming mono-cultures in natural areas, which are displacing the native plant populations.
http://www.inmygarden.org/archives/2005/12/callery_pear_tr.html

Confirmed reports of scattered infestations of the "harmless" Norway Maple forming mono-cultures in natural areas and displacing the native plant populations have been made in the Iowa City area.

I dont think that we need to elaborate upon the natural devastation wreaked upon our state by Purple Loosestrife (Lythrum salicaria) and its allegedly "sterile" cultivars.

The arguments, both pro and con, can go on forever with each side citing contradicting "facts" which trump equally contradicting "facts" from the opposing view. The point is that many of these problem plants dont seem to reveal their truly ugly side for a number of years until it is too late.

One guiding principle that I personally use is that if a plant is a problem plant in other domains, it brings with it a very likely potential for problems in my domain. Entrusting government bodies to act responsively within a timely period seems less than prudent to me. I have little abiding faith in the assurances of the "experts". Good intentions sometimes go wrong. After all, it has been estimated that over 75% of the exotic species now residing on the various invasive species lists were, in fact, originally introduced by the very same institutions now declaring them as invasive. Invasives like kudzu and crown vetch are but two examples. Does Dames Rocket also fit into this category of intentional (albeit, well-intentioned) introduction of invasives? It certainly does in many other states.

As with so many things in life, it comes down to a matter of personal choice. Is DR destined to become a thug throughout our fine state? Quite frankly, I dont know. It may eventually prove to be as harmless as a babys burp. However, what I do know is that we all have a choice whether to plant potentially invasive plants or not. Personally, with the vast selection of so many other wonderful plants available to each and every one of us, I see little incentive to make that choice.

Suffice it to say that I believe each of us should continue to raise our standards as we continue to grow as gardeners. Have I grown DR in the past? Admittedly, the answer is yes. However, I discontinued that practice over ten years ago, after I was on the receiving end of some "enlightened admonishment". After some cursory investigation, I saw the light and pulled the plants. I wound up selecting other plants that actually offered superior performance.

As I continue to garden, I continue to correct past mistakes. Concerted efforts are made to educate myself to "both sides" of issues gardening related or not. In the end, I am again left to make a choice. Although there are often many selections to choose from, I am behooved to select the best choice with a potential to produce the most collective good. I encourage others to do so as well.

IronBelly

IronBelly,

I am curious to know exactly which plants you chose to replace the Dame's Rocket plants in your garden. Thanks in advance.