To be perfectly honest, there is usually always more than one "correct" answer to a gardening question......that's why many reponses start with a "that depends" :-) Different locations, different climates and different gardening conditions can all influence how a plant will grow. It also makes a difference with the specific plant - some culitvars of yarrow are more compact than others.

The best way to get a definitive answer that will work for you is to try out the various suggestions you receive or read about. If you look online, virtually every source will advise staking yarrow so I'm not sure how 'inadequate' the MHS answer really is. One of the common reasons yarrow grows tall and floppy is that it is grown in overly rich soil - it would prefer it leaner and drier. Given that it is such an early bloomer, pinching is unlikely to produce great results: you may get compact plants but no flowers. Actually my experience with yarrow is that the plant will continue to extend or elongate throughout the growing season so pinching would not seem to be a particularly viable or efficient solution.

I failed to mention that the yarrows are huge. What would happen if I cut them back with shears-could I kill the plant, is this the right time to do this, I know I will cut the buds off but if this is the right thing to do, I don't mind if it doesn't bloom this year.

Regarding dividing the plant-is this easy to do and is this the right time to do it?

Thanks. I was in the legal world and I am very detail oriented! I didn't plant my first plant until I was 47 years old and love it! Enjoy learning new things.

Last summer was the first for my 'Strawberry Seduction' yarrow. At some point it gave forth wonderful blooms but it did need to be staked. And when these flowers were starting to fade I trimmed the plant back significantly and I thought that would be it for this yarrow that summer. But instead it recovered beautifully with flowering that went into late October and it never needed staking again.

A good way to prevent plants from "flopping" too much is to put a horizontal round section of fencing over the clump when it's small in the spring, using stakes roughly half the mature height of the species. Alternatively, you can also run cris-crossing strings between stakes at the same height.

As the plant grows up through the fencing or strings, they provide natural support and prevent significant flopping.

I did some reading and learned that yarrows should be divided every 3-5 years in early spring or fall. I will wait until fall. The directions "put a horizontal round section..." is over my head.

Here in Europe good catalogues mention if a plant can grow without staking. I know for sure that Martina and Credo are selfsupporting. There is also a plant evaluation from Chicago Botanical Garden, where they evaluated yarrows in this aspect. Look it up. For me, life is too short to bother with floppers.I just toss them into the garbage bin and slam the lid down.

Like this, but a homemade version with a section of fence and some wooden stakes. Much cheaper than buying it.

http://www.gardeninginfozone.com/wp-content/uploads/2010/11/plant-support-rings.jpg

I didn't know anything about yarrow until I bought some 8 yrs ago. I have bought several varieties, so far, the most impressive ones are "Gold Plate". These plants have not done any flopping and make an extremely sturdy clump.
While I love the color of Paprika and Walter Funke, I am unlikely to order more of them because they have proven to be rather weedy and floppy.
I agree w/ the opinion above, to look them up before ordering, also try cutting them back- why not...it's an option. Good luck.

I cut them back and will be interested to see what happens. I called a gardening show on the radio and they believe cutting it back will make it stronger, but suggested if I cut them back again, to do it a few weeks earlier before the buds appear. I thought dividing them made it stronger-maybe both?

In my experience all the millifolium varieties are weedy and floppy. Try A. 'Terracotta', 'Fireland', 'Moonshine' or 'Gold Plate' No floppin or staking needed.

I've also had problems with floppy Yarrow until I moved it into a spot in the garden that had leaner/sandier/dryer soil and most importantly, more sun. Problems solved. The spreading issues decreased, too. Also, since I have such limited space I find that a Yarrow like Moonshine that doesn't spread and is a great clumper works best for me. I'm going to experiment this year with Schwellenburg which is also supposed to be a good yellow non-spreading form.

lacyvail is the first person to mention different types of Yarrow. Are we talking Achillea millefolium or A filipendulina? Paprika is a millefolium. Gold Plate is filipendulina. They have very different habits. FWIW I've not noticed either flopping here. A few pea will sticks sort that out any way.

wieslaw59 - I am sure you don't really mean 'garbage bin.' Surely it's the compost heap they go to in green Denmark.