Weeds present peril to local ecology

So far, other than the yellow snapdragon-like, "Butter 'n' Eggs" or yellow toadflax, our yards have been spared. Most gardeners are at least attuned enough to know that when a funny looking plant appears among the grass in the lawns, something is amiss and we get rid of it. Unfortunately, there are darn few people doing the same for our parks and the land along our highways and byways.

Right now, it seems we are in the "yellow" flowering invasive phase as many of the flowers of these plants are yellow. Narrow-leaf hawksbeard is a dandelion look-alike, with yellow flowers so easily mistaken for dandelions that I get calls from people who are excited to find one that has a foot or two long stem and several flowers on each.

The perennial sow thistle is another dead ringer for a dandelion. Here too the stems are much longer and people get excited about seeing them. They should. Both of these plants have dandelion-like seed heads and roots that are more tenacious and even deeper. Once they do get established, they are almost impossible to get rid of.

Yet another yellow invasive, one that people actually think is a beautiful plant for the perennial garden, is the tansy. This one has deep roots and lots and lots of seeds. Don't plant it in your garden. One plant produces about 150,000 seeds and they remain viable for about 20 years.

It doesn't look like a dandelion, but leafy spurge has small yellow flowers. This euphorbia is a relative of the poinsettia. It has a killer root system with 200 to 300 buds forming on roots that extend out to 15 feet.

The oxeye daisy is another one of those plants people think would make a great perennial. It looks like the traditional daisy, white petals, yellow center, but it really spreads, both by roots and seeds and crowds out other vegetation.

Then, there is Canadian thistle with its characteristic "thistley" pink flower now in bloom. It is a spiny plant and hard to pull out. If roots are broken, they develop new plants. And the roots are deep and extensive. Once it takes hold, Canadian thistle is almost impossible to get rid of. The seeds are blown by the wind. At the very least do not let this one flower.

All of these plants are in bloom now and going to seed. Make sure you pick the seed heads if they exist on your property (and, frankly, while on walks around town). Mark the spot where these plants are located and pay particular attention to these areas next year. You have to stay on top of these things. We all do.

The real problem is that we are, as noted, surrounded. Ride your bike or walk off our property and you will, without fail unfortunately, find patches of these invasive plants and others within sight of your home. What can we do about these growing (pun intended) problems? We need to start thinking out loud, together and now so we can come up with solutions.

In fact, the problem is going to get worse if we don't figure out something to do about it.

Jeff Conn, a weed specialist with the USDA Agricultural Research Service (and a faculty member at UAF) found hay and straw purchased at Alaska feed stores had 15 weeds species not known to grow here (and 17 that do, which is making me reconsider straw as a mulch. It has to be local, at the very least).

They also incubated soil from plants bought at box stores and local nurseries and found 54 species of plants that people didn't know they were buying. Those are weeds.

We have a problem and as gardeners, we need to figure out how to solve it. In 1968 there were 175 exotic plants species here. In 2006, 275 were identified. The very first step is to learn to recognize these plants. The web is the place to start and this is as good a site as any; www.uaf.edu/ces/cnipm/plants.html. In addition, check out the Co-operative Extension Service display at the State Fair and pick up a free invasive and noxious weed I.D. Booklet.

Time is running out. We have to act now.

Jeff Lowenfels is a member of the Garden Writers Hall of Fame. You can reach him at teamingwithmicrobes.com or by calling 274-5297 during "The Garden Party" radio show from 10 a.m. to noon Saturdays on KBYR AM-700.

Jeff's garden calendar

The Fair: Go. Take pictures of the gardens. Don't skip the flower displays on the way to the big veggies. You should enter next year.

Baskets: Fuchsias and tuberous begonias don't do well with frost. Make sure yours are not exposed.

Plant A Row for The Hungry: Don't waste food. Take excess to Beans or a food bank. Give it to someone who needs it.