Mimosa Pudica Culture

I bought a small M. pudica last fall. It's grown from a few inches tall to about two and a half feet tall in just a couple of months. Very leggy and spindly as these plants usually are, but wonderfully healthy and vigorous. Almost all of the leaves react to touching or blowing. My boys and their friends love playing with it.

Since these plants don't last very long, and since it's now so leggy I have to stake it with bamboo shoots, I thought I'd start a new plant and see if I can make it bushier. I didn't try pinching the existing plant, because the stems are so long and spindly, and there appear to be no branches, buds, or other spots for new stems to start except at the very top.

I planted 10 seeds from a reputable dealer. I used a taint of soil from the existing plant to make sure the nitrogen-fixing bacteria would have a good start. Just one of the seeds germinated, and the seedling is growing strong and vigorous. It has one set of true leaves, and is just starting the second set.

My questions are these: Should I pinch to promote low branching? Can I get the stem thicker (woodier) than it would be otherwise? If so, when (and what) should I pinch? I don't know if it will react to pinching like a sweet pea, or if pinching will kill it. I've seen photos of M. pudica that look a bit like bonsai'd Mimosa trees, but I don't know how the owners got them that way. Ideally, I'd like this plant to grow into a low, dense shrub-like thing. It's okay if it gets tall and spindly eventually (it is M. pudica, after all), but I'd rather avoid having one three-foot stalk the width of a pencil lead, the way my current plant is.

I don't know much about the Mimosa pudica, except that it is an invasive weed down here in Florida. Here's some information in Plant Files for your plant: http://davesgarden.com/guides/pf/go/2573/ and if you scroll to the bottom you can read reviews from other folks who grow it.

Thanks for the link. I'd seen that thread before (but didn't remember where I'd seen it). Alas, no one there says anything about pinching or pruning to promote bushiness.

Here's hoping someone with success doing this will come along and impart wisdom.

I don't know if it will respond to pinching or not, but I wouldn't do it yet, I'd let the seedling get a bit bigger first.

Okay, we have an answer: Mimosa pudica does NOT like being pinched early. I very carefully removed only the top set of leaves after the seedling had three full sets of true leaves. The other leaves promptly fell off, and the top of the stalk yellowed.

The stem, up to where the cotyledons used to be, is still green and turgid, but the plant is basically a toothpick now. The stem above the cotyledon joint remains yellow, and is getting thinner and more wispy by the day.

Unless some new leaves or branches appear soon, this plant is dead.

Unfortuately, that one seedling was the only one (of fifty) to germinate in that batch. I planted another fifty seeds last week, and just this morning saw one peeking up. I'm going to let whatever comes from this batch grow however it wants. If I get at least two viable seeldings, I'll try pruning one of them, but only when the plant has more than one stem.