Here are three common garden myths debunked:

1. Vinegar is an effective weed killer.

It depends. If you are using household vinegar, which for the most part contains just five percent acetic acid, you’ll only see results if you spray small annual seedlings before they start growing in earnest.

When you spray, you are burning the seedlings with the acid. The acid breaks up cell membranes and makes them leak, causing the plant to dry out and die. With such a low level of acetic acid, it’s unlikely you will kill larger annual weeds or perennials. This is because young seedlings and new growth have a thinner leaf cuticle (a thin waxy layer that prevents the leaf or new growth from drying out) than do older plants or woody plant parts. The lack of that cuticle in seedlings makes it easier for the acid in vinegar to break down cell membranes.

Vinegar will only kill the parts of the plant it touches; it will not move through the plant’s system to kill roots. Be aware that acetic acid is non-selective. Exercise caution if you plan to spray in an area with new plant growth that you do not want to kill.

When it is in a concentration higher than 8 percent, it is called acetic acid and is classified as an herbicide, regulated by the EPA. Acetic acid can be purchased in concentrations as high as 30 percent.

The National Pesticide Information Center has labeled acetic acid with its highest toxicity level, Category 1 or “Danger.” Acetic acid is highly corrosive to eyes and the skin, and can also damage one’s internal organs if ingested or if inhaled as a vapor.

2. You should add gravel, stones or pot shards inside the bottom of individual or pot liners.

It is a myth that a layer of any of these coarser materials inside the bottom of an individual pot beneath the soil improves container drainage. Just the opposite. Since soil acts as a sponge and can hold water better than gravel, water will stay above the gravel until the soil is completely saturated and no air space among the soil particles remain. Only then will the water drain into the gravel or pot shards below. So, instead of extra water draining immediately into the gravel, the water “perches” or gathers in the soil just above the gravel. The water gathers until no air space is left. Once all the available soil air space fills up, then excess water drains into the gravel below. You may very well end up with soil that is so soggy, your plants will die.

3. Thin asparagus is tender, while thick asparagus is woody and tough.

In the past, asparagus growers would not harvest their crops until the third or fourth year from planting. Now, according to Peter Ferretti, professor of vegetable crops at Pennsylvania State University, growers harvest the thinner spears in the second crop year, often selling them as “gourmet.”

“Although we may think younger and thinner equals tenderness, the opposite is true for asparagus,” says Peter Ferretti, professor of vegetable crops at Pennsylvania State University, “a young asparagus plant is putting more of its energy into producing spears that will stand upright, so most of the plant material in the spears of younger asparagus plants is crude fiber.” As the asparagus plant matures, less growth is dedicated to producing crude fiber and the spears thicken with soft, soluble fiber and other nutrients. You will find that the “whips” are generally higher in fiber and tougher to eat than large diameter spears. That is because most of the fiber in asparagus is in the skins, making the larger spear the more tender.

If you’re growing asparagus yourself, plan on harvesting the second- and third-year crop, even though the stalks will be thin. Harvest over a period of four-seven weeks during the season by snapping the spears off close to the base of the plant. This will stimulate more bud production for future crops. After the end of the harvest season, the spears should be allowed to grow, leaving them in the ground over winter. These spears will contribute to the growth of the plant.

WSU Extension programs and employment are available without discrimination. Reasonable accommodations will be made for persons with disabilities and special needs who contact Toni Gwin, WSU Extension, P.O. Box 88, South Bend, WA 98586, 360-875-9331; tgwin@wsu.edu at least two weeks prior to the event.

Mary Shane, a Master Gardener since 1998, lives in the Val Vista area west of Montesano.