Not all topsoils are equal, and topsoil might not necessarily even be good. For topsoil, the buyer will have to beware lest he buy a topsoil that will perform poorly or is contaminated. Garden centers generally try to sell topsoil that looks good in quality, but the buyer can run a few simple checks prior to purchasing the soil.
A good topsoil is one that is free of large rocks, does not contain excess gravel, is free of garbage, has no signs of contamination, and looks clean. Topsoil is not weed free; it is not uncommon to see weeds growing in the topsoil, but these can be eliminated through the use of mulch or the lawnmower, depending on what it is used for.
Topsoil is either picked up or delivered. If you are picking it up, look at the pile before you go to purchase it. Most garden centers let customers look at the soil piles first. If it is being delivered, arrive in person rather than ordering on the phone, and look at the pile. Do this immediately before having it delivered; if you wait a week after ordering a delivery, the soil you see and the soil you receive are two different loads often.
Ask where the garden center gets their soil from. If they cite a reputable company, the chances are they are buying good soil in consistently. If the garden center acquires the soil from random companies or from jobs, it is hit and miss as to how good it will be. Look at the pile. Is it new? Has it sat there for some time? If it has sat for some time, weeds are a sign the pile supports plant life. Old soil on the edges of the pile often have weeds growing; this indicates the health of the soil. Observing the types of weeds that are growing may possibly say something about where the soil came from as well.
Are there rocks or gravel in the pile? If there are medium or large rocks in the pile, other than any used to hold a tarp down, this indicates that the provider of the topsoil doesn’t care for a reliable product. Likewise, look for roots and branches as well. The presence of any man-made trash is a red flag; don’t buy the topsoil if it has any garbage in it. If there is excessive gravel, you are not getting pure topsoil but rather, clean fill. Gravel will not enrich a lawn or a garden, and you are not getting what you are paying for.
Is the soil waterlogged? If the bottom of the pile is being scraped, and it is sitting in water, you will get mud in place of topsoil. Not only is mud harder to spread, but it also harbors diseases.
Is the topsoil excessively sandy? A sandy topsoil, although clean in itself, is not suitable for growing lawns or gardens as it does not hold water or nutrients well. If the topsoil is needed for clean fill, a sandy topsoil will work. Is the soil too silty or clay? A topsoil with too fine a texture will not drain well, and water that lands on it will run off excessively or puddle. The soil will also compact and restrict air and water availability for the plants. Topsoil that is too sandy or clay are easy to spot on a close examination of the material.
Does the topsoil have organic matter? A good topsoil will contain organic matter; if the topsoil has too much organic matter, it will compact under normal use. Organic matter often is indicated by the soil being darker in color, though some soils are naturally red in color despite having organic matter. If a soil is a dark grayish color, it may have come from a wetland. Soil dredged from wetlands often adapts poorly to normal usage. Once used, topsoil can be enriched with fertilizers or organic matter. Sandy soils can be made good through adding organic matter. Adding organic matter to heavy soils is more effective than adding sand, both for drainage as well as for nutrient content of the soil.
By knowing what to look for, you can avoid buying a topsoil that will not do well after installed.