Reader suggestions for clearing new beds

By Audrey Post
MS. GROW-IT-ALL

Last week’s column dealt with clearing weeds from an area in order to create a flower bed, and I suggested removing the weeds by hand. Two readers wrote with additional, and very different, suggestions.

“The best way to prepare a new bed is to mulch it heavily with hay. That will kill the weeds. Do not till. Do not use poisons. Continue to add more hay as it decomposes into the soil,” e-mailed Steven P. Christman, senior scientist and editor at Floridata.com, a very informative and useful local gardening Web site. A Florida master gardener with a Ph.D. in biology from the University of Florida, he has used this method in both vegetable and flower gardens.

Christman’s advice brings to mind one of my father’s favorite gardening books, “Gardening Without Work” by Ruth Stout, who also believed in the no-till method using hay. In addition to smothering weeds and saving your back, it also continuously improves the soil structure.

Bob Brown wrote to suggest using calcium cyanamide. “I have used this compound many times, and it is completely safe if handled correctly (i.e., with gloves),” Brown said in his e-mail. “It really does kill everything growing, plus dormant seeds. It is inexpensive and not ecologically dangerous to water systems as it breaks down to nitrate, which is readily used by the succeeding plants as a fertilizer, and leaves no residue. In lower doses, it is used as a commercial nitrate fertilizer.”

A Web site he recommended, http://www.improve-your-garden-soil.com/, gave the following description:

“Calcium cyanamide is a granular material that at first breaks down into substances poisonous to seeds but later converts into valuable nitrogen and lime. It is a grim coffin-gray in color and even looks poisonous to handle, but is safe if used as directed. The soil to be treated should be plowed or rotary tilled and leveled just before application. After 60 days you can plant seed, but disturb the soil surface as little as possible to avoid bringing up new weed seeds. The 60-day wait is one drawback to this material. Since soil should be warm during treatment, this means you have an unplanted lawn or garden during the major part of the growing period, which some gardeners find too unpleasant a sight to face.”

“A lawn I treated in this way four years ago came up without a single weed and, except for a few seeds blown in from the outside, has had no weeds since.”

This Web site is the personal project of a lifelong gardener named Robert Harris, who seems committed to helping fellow gardeners learn about the importance of soil. Our growing season is a bit longer than 60 days, but other than that, the information seems applicable here.

Skip 'Weed & Feed,' pull weeds from future beds

By Audrey Post
MS. GROW-IT-ALL

Q: I have an area along a sidewalk path that I want to turn into a flower garden. Right now, it is covered in different weeds. Can I spray "Weed and Feed" on those weeds and remove them from the area after they die? After that, I want to add some manufactured soil mix and plant my flowers and cover them with pine straw. Will the "Weed & Feed" be impossible to remove from the soil and kill whatever I plant in that area?

A: Whether you’ll be able to remove the “Weed and Feed” from the soil is really a secondary issue to whether the product will remove the weeds, thus allowing you to plant flowers in the area. Most “Weed and Feed” products are intended to feed the predominant plant in a given area while killing or preventing the growth of other plants.

In the case of grassy areas, “Weed and Feed” blends for lawns fertilize turf grass while inhibiting the growth of weeds and/or killing those that are present. Read the label to make sure you’re using a blend that feeds your specific kind of grass.

“Weed and Feed” formulas for flower beds fertilize the plants that are actively growing in the bed while inhibiting seed germination, generally preventing the growth of new weeds but also stopping any flower seed from germinating. It requires removing the weeds that are already growing before applying to be effective.

Using any kind of “Weed and Feed” concoction without removing existing weeds will simply feed the weeds that are there and prevent any seeds in the soil – whatever they are – from germinating. Since you want to convert a weedy area into a flower garden, this is not the right product for the job.

The best way to remove the weeds from your future flower bed is to dig them out by hand. You can use a chemical weed remover – not a “Weed and Feed” but a weed killer -- but you’ll have to wait until the residue has washed out of the area before you plant. The label on the weed remover will tell you how long you need to wait after application before you plant, but it sometimes takes multiple applications to kill existing weeds – especially if there are a lot of them. This could take a while, so you’ll save time and money as well as going “greener” if you dig out the weeds.

Once you have the weeds out, you can amend the soil with peat moss or compost to improve its structure and quality. I’m not sure what you mean by “manufactured soil mix,” but it doesn’t sound like anything you want to put into the ground. Save it for containers.