Seafood for Roses

By Mike Chute

    Roses love to eat. Like people, roses love seafood served on a regular basis and seaweed, the seafood of roses, can be found in abundance here in coastal New England. Rhode Island is divided roughly in half by Narragansett Bay which explains why it has over 400 miles of coastline. With this much coastline, there is no shortage of seaweed which can be used as mulch, soil conditioner, and a winter cover for roses.

While seaweed is a low-analysis fertilizer, more or less equivalent to that of farm manure, it is a teeming stew of micronutrients, hormones, vitamins, trace minerals, enzymes, amino acids, and growth stimulants, which are directly available to plants. Seaweed contains all the major and minor nutrients, as well as most of the trace elements, including manganese, iron, boron, zinc, copper, and a chelating agent known as mannitol, a simple sugar that makes micronutrients already in the soil available to the rose. Coastal rose gardeners mulch their rose beds freely with fresh seaweed without concern for salinity. Anecdotal evidence indicates no ill effects to the soil from salt with moderate seaweed use. Seaweed conserves soil moisture and controls weeds but brings no weed seeds or plant diseases with it to the garden. University of Rhode Island researchers report that seaweed usage may result in increased plant resistance to mites and aphids and some diseases and maybe even to cold temperatures. When used as a winter cover and turned into the soil in the spring, it decomposes quickly, stimulating soil microorganisms that, in turn, breakdown nutrients in the soil into forms that plants can absorb. As an organic amendment, it enhances the soil’s ability to hold moisture, helps prevent wide swings in pH, and improves the tilth of the soil.

Seaweed is readily available for harvest. Just head to the beach with a rake and basket and help yourself. Here in Rhode Island, it is not possible to be more than a thirty-minute drive from the seashore from any point in the state. In fact, the Rhode Island constitution guarantees its citizens the right to gather seaweed from any public source.

I have discovered several quiet, out-of–the-way, seaside nooks around the state where I gathered good seaweed late last fall. There is one special stash where the seaweed is superb and lies knee-deep at the high water mark. All I had to do was bag it up with the help of the local squire and toss it into the truck. I can attest, however, that fresh seaweed has the distinct aroma of low tide, so be sure to bring it home in someone else’s car.

If seaweed collection is not an option, there are seaweed concentrates, extracts, and liquid products that can be found in garden centers and catalogs. I use a product called Response, a non-toxic seaweed based fertilizer, in my spray solution as a foliar feed. It has improved my foliage, keeping it green and healthy, and enhances the effects of the other spray chemicals in the mix. It can also be applied directly into the soil as a drench. (Available online at www.rosemania.com)

I use seaweed liberally in my garden as mulch, sometimes mixed with horse manure, and a winter cover. I like liquid fish emulsions and seaweed extracts, too, and use them as part of my liquid fertilizer program. These are all available in local garden centers. I add these products to water-soluble fertilizers like Miracle-Gro or Magnum Grow, cut the dosages of everything, and feed weekly. What could be more Rhode Island than using products from the ocean to make plants grow?

However you do this, be sure to put seafood on the menu in your rose garden and enjoy the results.

(Reprinted from Rhode Island Rose Review May 2003)

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Date last edited: 01/21/10
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