A number of great gardening products are harvested from the sea. Here are a few of gardener Paul James' favorites.

A number of great gardening products are harvested from the sea. Here are a few of gardener Paul James' favorites.

Kelp or seaweed powder is loaded with all kinds of goodies that plants need for proper growth. It's easy to apply: just mix with water and either drench the soil around the base of plants or spray it directly onto the foliage.

Also easy to apply, seabird guano is an all-natural, pelletized product that's packed with nutrients, including 12 percent nitrogen, 12 percent phosphorous and 2.5 percent potassium, plus calcium. The relatively high percentage of phosphorous makes it ideal for blooming and fruiting plants.

Finally, fish emulsion, an organic byproduct of the fish-processing industry, is a dynamite organic fertilizer, and you can use it on anything that grows: trees, shrubs, flowers, vegetables and lawns. A little goes a long way, and you can apply it two ways, either as a soil drench (simply mix the concentrated emulsion with water according to the label instructions and apply directly to the soil) or as foliar feeding (mix as directed and spray on plant leaves).

James is a huge advocate of foliar feeding every two or three weeks. In addition to providing plants with a quick blast of nutrients, foliar feeding also seems to prevent fungal diseases, in particular downy and powdery mildew. For best results, try to spray during the coolest part of the day, ideally early in the morning.

One last note: Both kelp-based products and sea-bird guano are great for landscape plants and houseplants. Fish emulsion, however, unless it's been deodorized, is best used on landscape plants only for one simple reason: it stinks!