I'm not sure that you're going about this the right way. Understanding how some of these allelopathic substances work (and where they are) is important. Fennel is a real interesting plant and can cause many different kinds of plants problems in a wide variety of ways. Since you are most interested in inhibiting seed germination, you need to use leaves (as in the leaf litter), and the seeds of this plant. Many different plants contain allelopathic chemicals within the oils of their seeds and/or seed hulls. Fennel is a prime example. But not all plants will be affected by this chemical reaction. You might have to experiment. Sunflower seed hulls are another example such as the one above. You are correct in that these chemical properties are found elsewhere within plants than the much advertised root exudates. But not from gases expelled from the leaves, but of leaf litter and/or water run-off from the foliage and stems. Pine straw, by the way, has been proved to have seed inhibition properties, but I've not ever seen a list of the affected (sensitive) plants. One product with a fairly wide range of effectiveness is corn gluten meal. I'm most familiar with its use on turf (lawns, sports fields), but is also highly recommended for other areas, as well.

I have had very dense clay soil where I live now but also at a house I was renting. There, I found it very effective (with little effort on my part, i.e. no digging) to cover over the entire area with several layers of newspaper, wet it thoroughly and cover with mulch of your choice. I've found this effective in that kind of soil and was very sucessful planting flowers after a week or so by digging through the mulch and poking holes through the paper for each plant. The weeds didn't come back for at least a few years (I moved after that so I'm not sure if or when they did). You might give that s hot - all you'll have to lose is some newpaper really and depending on the size of the area you are covering it shouldn't take too long.

Ok, you all have me almost convinced to buy myself the Kindle. I just downloaded the app to my iphone. That's all I've done on it so far! The battery is low so I'll have to play with downloading books on it later. Lindsey, I love the idea of putting knitting patterns on it! I scanned some of my pattern pics with the materials list into the computer and printed them in photos, then put them in "brag books" to take with me to yarn shops so I would have the info to buy yarn, or not duplicate patterns, but I've always carried my knitting bag with a bunch of my favorite patterns in it, and my needles when we traveled. Luckily, we don't fly! When we took the train, I vacuumpacked each skein of yarn seperately for a sweater I was working on, and put them in the suit case. I could take out one at a time, and it would puff back up to it's original shape to work with. I knitted 2/3 of a sweater in 10 days that trip! But that bag is HEAVY! With the kindle, I could just carry that, my needles & accessory kit. Hmmm, guess I'll have to check the ccard balances. Trip to KS for a funeral=4 day weekend, gas, food, room. Trip to S. Ohio for bluegrass festival = room, gas, food, tickets, cd, banjo, music stand, & 3 instrument stands. Have to think about it. Tami

The Kindle will put itself into Sleep Mode after 10 minutes of inactivity (e.g., you don't go to the next page of the book you're reading). There are hundreds (if not thousands) of free Kindle downloads. You can also download the first chapter of any book for free as a "sample" to decide if it captures your attention enough to purchase the book. I've been reading on my Kindle for several hours today. Just handed it over to hubs because he wants to read a book on it and I wanted to come to my 'puter and go online for a while. One thing that's so nice about reading on the Kindle is that you can hold it in one hand and turn to the next page to keep reading, no matter which hand you're using - right or left... so it's much more efficient than having to turn the pages of a physical book. One big difference between a Kindle and a Nook is that a Nook weighs about 2 ounces more than a Kindle, so if you read for hours, as I tend to do, the Nook would feel much heavier than the Kindle and it might be more tiresome to hold it for long periods of time. I've read some comparisons of the Nook and Kindle where the reviewers say how much nicer they think the Nook is because you can choose from different colored backs for it. My opinion on that? Who the heck cares? When I'm reading the Kindle, I'm looking at the FRONT of it, not the back. AND, there are hundreds and hundreds of different "skins" available for both the front and back of the Kindle, so you can customize it however you see fit.