Margaret Lauterbach

Increase your knowledge of weeds, and learn proper fertilization amounts

One of the benefits of having a friend trained in botany is obtaining the correct identification of a weed. A weed invaded my yard a few years ago and proliferated, taking up most of an area in which I once grew herbs. This weed has a mild burr effect, clinging to your clothes when you pass or pull it, so I presumed it was a medicinal herb called “cleavers.” It was an area inaccessible to me, so I offered to “let” my friend Lindarose Curtis-Bruce harvest cleavers. She took one look and said, “That’s not cleavers, it’s Rubia tinctorum, a dye plant.” I insisted that it looked like cleavers, and she agreed, but said “it’s just in the same family.” She pulled a branch and showed me the yellowish-red base of the stalk, freed from the root that contains alizarin, a valuable dye pigment.

Knowing that another dye plant, Woad, is on the Idaho noxious species list, I checked to see whether Rubia tinctorum or Madder Dye plant (its common name) was on the list. It is not, under either name. The noxious species list is at R. tinctorum and other members of the Rubiaceae family are also known as bedstraw, madder or coffee family.

I have a lot of Madder dye plant, at least 100 square feet. It has been known for more than five millennia, originating in the Indus area, apparently. Once its coloring capability was discovered, it was grown for that purpose in the Middle East, Europe and south-central Asia. It reproduces by seeds and must be at least 2 years old before roots are dug for dyeing purposes.

A mordant such as alum must be used with plant parts to “fix” the color in fabrics. Roots produce a red dye, but the upper part of the plant can produce shades of coral-pink and tan. Roots should be pencil-thick when dug in spring or fall. The upper part of the plant, intended to be used as a dye plant, should be harvested after they’ve died down and appear straw-like. To use this plant for dyeing, alkalinity helps, and we have plenty of that. One woman who works with yarns and fabrics is trying out this dye plant.

▪  During the 19th century and early 20th century, horticultural experts began to improve methods of gardening to produce more interesting flowers and better foods. Sir Albert Howard, at the forefront of that movement, wrote that when the soil is healthy, plants are healthy and then people or animals that consume those plants are healthy. That condition is still true today, so it really pays gardeners to keep our soil healthy.

When we overfertilize or underfertilize our plants, we have infestations of destructive insects, either gorging on super-tender new growth or feeding on sickly plants. Balance is very important in gardening, and when one sees that a little is beneficial, that never means more will be more beneficial. Take it easy with fertilizers , especially those with high nitrogen content. Organic fertilizers help keep the soil healthy, but those with synthetic ingredients are not feeding the microscopic flora and fauna necessary for healthy soil.

One of the best gardeners I’ve ever known uses fertilizer in such diluted amounts that you’d think it wouldn’t make a difference, but it does. Most of us have fruit trees surrounded by lawn, and we’ve got to remember that the trees will take up some of the fertilizer spread on the lawn, so we probably shouldn’t have to fertilize our fruit trees at all. A friend built a raised bed on his lawn and said he didn’t fertilize the tomato plant in that bed, but he saw the plant vigorously put out foliage, and no blossoms or fruit at all. That’s a clear sign the plant had taken up too much nitrogen.

Our high pH does block the uptake of soil iron, so we often get yellowed (chlorotic) leaves on fruit shrubs and trees. We can foliar feed chelated iron, but chances of turning yellowed leaves green again are slim. In late July or early August, chile plants in my garden may have lighter green leaves than they should. When that happens, I use a foliar spray of one teaspoon of Epsom salts dissolved in a pint of water. Those leaves do redarken rather quickly.

I don’t use Ironite for an iron supplement because its content includes arsenic and lead. It’s illegal in Canada, and several states are considering outlawing its use in their areas. On the whole, Dr. Earth’s fertilizers are very good, but I’m also very fond of the Alaska Fish Fertilizer products because they’re effective and inexpensive. Morbloom, for instance, has a content of 0 nitrogen, 10% phosphorus and 10% potassium, boosting flowering and fruit on ornamentals and vegetables.

Send garden questions to or Gardening, The Statesman, P.O. Box 40, Boise, ID 83707.