Let Weeds Provide the Flower Power for Your Garden

by Tom Spencer / Soul of the Garden

Some of my favorite plants are weeds. I mean real weeds, not genteel wild flowers. No, these are botanical conquistadors bent on total garden domination. I admire them in much the same way that you might admire a prizefighter that just keeps on swinging- they never seem to go down for the count. Here in Austin, with our blazing summers and miserable excuse for soil, we need tough determined survivors and these weeds will not disappoint fans of full contact gardening.

Gardening with bullies is not for everyone, you have to be a little bit aggressive yourself or your first-born may disappear in the jungle. Still, there is something to be said for gardening the Darwinian way. I know many folks who have simply turned some of these weeds loose, letting them "sort things out for themselves." It can get ugly, but if you have a large space to fill and want some plants that will positively swarm across the landscape, these are the weeds for you.

Every spring, hundreds of central Austin yards light up with the intense purple color of the spiderwort (Trandescantia occidentalis). It is so pervasive in certain neighborhoods, that I think that it must be the slacker flower of choice. I've never seen a "yard of the month" sign in front of a spiderwort patch, but the folks who live with them must appreciate their tenacity and beauty. There are named varieties that range in color from purple to blue and white for those of you who'd like to mix things up a bit. Spiderworts perform well in clay soils and can grow in the sun or shade; they quickly reach a height of two or three feet in the early spring, and then go dormant (in situations where they receive no water.) They seed out exponentially, meaning, you can buy a few plants, and in five years, you'll be able to export spiderworts to every family in China.

In a site that gets a little bit of water, Mexican petunias (the various members of the Ruellia family) can make spiderwort look like a chump. In my former garden, waves of ruellia formed tsunamis that swamped neighboring plants and, come to think of it, a few neighbors. Their blooms do resemble a small petunia, but their demeanor is decidedly different. Ruellias spread by their roots and by flinging seed out from their dried seedpods. Judging from the "volunteers" that popped up everywhere in my garden, they seem to be able to rocket their tiny seeds about thirty feet away from the mother ship.

There are many forms of ruellia, from ground huggers, to monsters that grow four feet tall. Named varieties include "chi-chi" (yikes!) which features soft pink blooms and narrow willow-like leaves and grows to three feet, and "katy" which is a dwarf purple flowered variety.

Turk's cap (Malvaviscus arboreus var. Drummondii) is another ubiquitous feature of the central Austin landscape. This shrubby member of the hibiscus clan gets its name from the tassel like red blooms that grow on the ends of its branches. Turk's cap is valued as a hummingbird and butterfly attractor and seems to have settled into every shady nook around town. It has a sneaky way of taking over a garden- the long branches stretch out and then root when they touch the ground. It also spreads from fallen fruit and by the roots. Plant a few of these and you will be unleashing the ottoman horde.

Purple loosestrife (Lythrum salicaria) is such a weed that it is actually banned in some locales. However, it also has many fans for its long-lived display of pinkish flower spikes. Purple loosestrife likes full sun and can tolerate most soil conditions. Some of the varieties of loosestrife can grow up to five feet tall, but the most commonly available forms, "Morden's Pink" and "Rose Queen", are more compact. These cultivars are better behaved than those that are banned in Boston, but they can slug it out with the best of 'em. What do you expect from a plant that lets loose strife?

Oxalis or woods-sorrel is my favorite weed of all time. This shade loving plant pops up everywhere and just refuses to quit. I like using it as a ground cover by itself, or mixing it in with other perennials. It has clover like leaves and is often sold as "shamrocks". Like most true weeds, oxalis comes in many forms and colors. I just finished planting a bed of pink and white oxalis arranged in a yin-yang pattern. It is the weed of the Tao.

Before I wrap up this month's article, I need to offer up a mea culpa. In the March edition of Over the Hedge, I wrote about lawn grasses. In that article, I wrote that zoysia grass would not tolerate the shade. I received some excellent feedback from the landscape community that suggests that the new cultivars of zoysia outperform the competition in conditions ranging from sun to shade. From here on in, I'm a zoy boy.

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