Using Soil Amendments

Soil amendments improve the physical nature of soil

Whether you are planting your latest plant find from the nursery or just preparing your beds for mulching, you should amend your soil with a good soil amendment. If you ask the average homeowner, they will describe their soil as pretty good. In actuality, most of the soils in our area are compacted, heavy clay, with little amounts of organic matter. Soil amendments such as compost and hummus are made from organic material (previously living) that help aerate compacted soil, improve drainage, act as a storehouse for nutrients, help in root expansion, and feed soil microorganisms. Soil amendments can also help your plants grow better and healthier

Soil amendments reduce compaction, aerating the soil to allow water and nutrients to move through it more efficiently, and reach plant roots. Some soil amendments also add nutrients to the earth, help retain moisture, and maintain the correct pH balance.

Adding soil amendments

On larger projects such as when constructing new planting beds or adding a vegetable garden, use a pre-blended soil and compost mix such as Gasper’s organic soil blend (with Soil King leaf mold) or premium organic soil (with Earthmate, a nutrient-rich organic compost). Both are sold in cubic yard amounts, premixed, and can be delivered right to the house. You can find some on our bulk delivery page. These products should be spread on the intended area and rototilled into existing soil to a depth of 6- to 8-inches. In a raised bed situation, use soil mixes to fill planters.

Bagged product

There are many soil amendment products available, and all will be somewhat helpful to your garden. The best will have a diverse source of nutrients to improve your soil. Many people know and use peat moss. Peat moss’ effect is limited, as it decomposes quickly, has no nutrient value, and its use is environmentally questionable because of habitat destruction. Only use small amounts for water retention. 

A better choice is mushroom soil, organic manure, or a compost mix. These are rich in nutrients, longer-lasting, and made from recycled agricultural products. At Gasper, we feel the best is Coast of Maine’s Bumper Crop ― a diverse mix of nutrient-rich ingredients such as worm casting, manures, and seaweed. Bumper Crop will be a reservoir of nutrients that will continuously feed your plants, enrich your soil, and increase disease resistance. A yearly top-dress around your plants or tilled into vegetable or flower gardens will deliver a “bumper crop” in your garden!

When planting smaller projects such as a new shrub, tree, or flat of flowers, it is easier and more cost-efficient to use bagged products. Gasper has many bagged mixes such as Bumper CropMushroom Soilorganic manure, and compost. After excavating the soil to prepare a hole for planting, add a soil amendment at a 50/50 ratio. Backfill the new combined soil into a hole twice as wide as the plant ball or container. It is also a good idea to add a starter fertilizer such as Espoma Biotone Plant Starter or any Dr. Earth fertilizer at this time. The fertilizer will significantly speed root development and help speed the establishment of your new plant(s).

Established plant beds

Soil amendments can also be used as a top-dress around existing plants by lightly working them into the top few inches of soil with a garden weasel. Another way to amend the soil in an existing garden is by top-dressing the bed with an inch or two of compost each season. The compost will break down, improving soil structure and fertility. Plus, you’ll perk up your perennials.

Two out of every five people on Earth today owe their lives to the higher crop outputs that fertilizer has made possible.

Bill Gates, Businessman