What’s in your soil?

What's in your soil?

Soil Conditions – Loam – Sand – Crushed Stone – Gravel

What kind of soil conditions exist below the grassy field or in the woods that you are thinking of clearing or using to expand your landscape? If you have existing soil you need to examine, take soil samples and find a reputable test facility in your area or take it to your local university extension office for testing. There are kits available which allow you do your own tests, but they are not as reliable as a professional quality testing facility. Many engineering firms that design septic systems have soil testing facilities. Call and arrange to pick up a test kit from them or have the firm do it for you. After you get your results back you may wish to amend (enhance or improve) your soil to balance your pH, improve the organic base or make it more conducive to a specific landscaping project.

Soil Sample

What kind of soil, sand or stone do you need for your next landscaping project? Below are some terms that you will run across when you go to purchase aggregate, sand or loam. An aggregate can mean many things so always ask what’s in the aggregate blend. Aggregate is commonly used as a term for crushed stone, but in reality it can be any kind of mixture of stones or soil.

Thesaurus: aggregate ‘noun’ 1. the specimen is an aggregate of rock and mineral fragments: collection, mass, agglomeration, conglomerate, assemblage; mixture, mix, combination, blend, accumulation; compound, alloy, amalgam.

Good Dirt

You are also going to encounter terms like unscreened loam, screened loam, screened sand or washed sand. Question the size of the screen. 1/2″ screen is a highly screened loam where as a 2″ screen will be full of rocks under 2″ in size. You get the meaning? 1/2″ screen removes anything in the soil aggregate that is over 1/2″ in diameter to a degree. The screen might be 1/2″ by 4″ so you may get an occasional chunk of stone or organic material larger than 1/2″.

Soil or Good Old Dirt

• Screened Loam is usually screened to 1/2″ so anything over a 1/2″ in diameter is removed. The screens are not 1/2″ x 1/2″. They are usually 1/2″ x 6″ or 8″ so something long and flat or a stick may be present in the aggregate. Loam can be organic containing sticks, weeds, grass and weed-seeds or washed with weed-seed killing chemicals. Ask if it matters to you. Screen loam will usually come in a variety of mixtures by bag or in bulk and be careful that it is not mostly sand. Ask to see it dry if it is wet. You want loam that will stick together somewhat when dry. That means it has the right mix of loam, organic materials and sand. Some loam is sand free, but you need to ask what mixture you are buying.
• Farm Loam is usually the richest loam you can buy. Unscreened it comes directly off the fields to you, however, it is usally sold as a mixture. Farm loam is regularly mixed with sand and compost materials to lighten its structure. Unmixed farm loam can pack like concrete when it dries out and must be regularly cultivated. If you do get loam directly off the fields unscreened it is best to mix your own before using it for planting beds or lawns. I use sand, peatmoss, bagged organic compost and dried manure to make a rich soil that also drains well. When specific plants call for specific soil conditions mixing your own is a great idea.

Compost – organic materials combined, “roasted” and screened.

• High in nutrients and a great addition to your soil.
• Use in garden beds or when installing a new lawn or overseeding an existing lawn.
• Other applications include use in container gardening and indoor plants with the right mixture of loam and sand.

Bank Run Gravel – Gravel pit special. From the earth directly to you for fill. Not screened and contains almost anything.

Crushed Stone (Sometimes referred to as aggregate in the industry)

• 3/4″ granite – Drainage, economical decorating choice for walkways and around shrubs or trees. Usually installed over landscape fabric.
• 1 1/2″ granite – drainage above or below grade, drywells
• Hard Pack – aggregate of various sized stone and stone dust for driveways and some situations it may be used under walkways or patios or in combination with sand where speedy drainage is an issue.
• Stone Dust – crushed aggregate that packs like concrete. Sometimes used for base under walkways, patios and stonewalls where drainage is not an issue. Not good for drainage and misused a lot under walkways and patios. Questions? Send me one. I’ll explain further and respond to your specific conditions.
• Colored Crushed Stone – This can be granite, slate, marble quartz or even crushed field stone. Usually comes in 3/4″, 1/2″ or 1/4″ sizes.
• Pea Stone or Peastone – 1/4″ round stone that has been screened. Usually contains a lot of stone dust.
• Round Stone – screened natural round stone that can come in sizes from 1/2″ up to 3″ or more. Starts becoming wall stone when it gets over 6″ in diameter.

Sand (To do most landscaping jobs right you need sand that is specialized for your need whether it be for drainage, masonry, walkways, patios, play areas, pond bottoms and beaches or even zen gardens.

• Screened Sand/Concrete Sand
  • Screened to a 1/4″; clean fill, soil corrections, building pads, backfilling, etc.
• Play Sand
  • Perfect for sand boxes, play areas, beaches and volleyball or badminton courts.
• Ball Field or Packing Sand
  • Firmer with a clay additive for a denser, softer mix that packs well enough to use as a base under patios and walkways and still allow for excellent drainage. Use on athletic playing fields, horse shoe pits and horse stalls or barns.
• Sand Fill
  • Great for leveling off areas before applying topsoil
  • Fill for areas you need excellent drainage such as behind retaining walls or a base for a large terracing project where drainage will be critical.
• White Trap Sand
  • White sand for golf course sand traps or zen gardens.
  • Sometimes fine enough for sand filters. Best to buy filter sand at a pool store to assure the best quality. I have used filter sand in my zen gardens purchased at pool stores.
• Mortar Sand
  • Masonry applications.
• Washed Concrete Sand
  • Washed sand conforming to a tight well-graded specification.

I probably missed some stuff so if you have any further questions please fill out the comment box or form on the website. I’ll be happy to answer any questions you might have or direct you to a source that can answer your question.

Tagged as: aggregate, Garden Design, Lawns, SOIL