A natural limestone soil amendment that neutralizes acidic soil while supplying both calcium and magnesium — two nutrients most lime products deliver only one of. Apply before planting for stable, long-lasting pH correction throughout the growing season.
Neutralizes acidic soils in the pH 4–6 range, bringing them toward the 6.0–7.0 window where nutrient uptake is most efficient for most crops.
Calcium strengthens plant cell walls, supports root tip development, and can help prevent calcium-deficiency disorders like blossom end rot in tomatoes and tip burn in lettuce.
Magnesium is the central atom of the chlorophyll molecule. Adequate magnesium is essential for photosynthesis and can correct the interveinal yellowing (chlorosis) caused by Mg deficiency.
The near 2:1 calcium-to-magnesium ratio in dolomite mirrors the ratio plants typically need, helping to reduce the risk of antagonism between these two competing cations.
Dolomite dissolves more gradually than calcitic lime, providing stable pH correction over months rather than a rapid spike that can overshoot the target range.
A finely ground powder has greater surface area than pelletized or coarse lime, which means faster dissolution, more thorough mixing, and more consistent soil contact.
Many beneficial soil bacteria and fungi thrive in near-neutral pH. Correcting acidity with dolomite can create a more hospitable environment for the microbial communities that drive nutrient cycling.
Adding dolomite between compost layers neutralizes acidic breakdown products, reduces odors, and enriches finished compost with calcium and magnesium.
Suitable for vegetable gardens, lawns, orchards, flower beds, compost piles, and as a calcium-magnesium supplement in animal feeds — one product with wide utility.
Registered with the California Department of Food and Agriculture and independently tested for heavy metal content, providing documented quality assurance for commercial and home use.
Dolomite lime is a naturally occurring sedimentary rock composed of calcium carbonate (CaCO₃) and magnesium carbonate (MgCO₃) that formed over millions of years from mineral-rich marine sediments. It is mined, crushed, and finely ground — no synthetic additives, no chemical processing. The result is a pure mineral amendment with a naturally consistent calcium and magnesium profile.
A double carbonate mineral that supplies both calcium and magnesium simultaneously. When it reacts with soil water and acids, it releases Ca²⁺ and Mg²⁺ ions directly into the soil solution while neutralizing hydrogen ions (H⁺) that cause acidity.
Adds calcium and sulfur without affecting soil pH — ideal when pH is already in range but calcium or drainage improvement is needed.
Fast-acting soluble magnesium for immediate correction of Mg deficiency, without the slow-release buffer of dolomite.
Soil acidity is caused by an excess of hydrogen ions (H⁺). When dolomite's carbonate compounds dissolve in soil moisture, they react with these hydrogen ions and neutralize them — raising pH in a buffered, gradual process. Because dolomite contains magnesium carbonate in addition to calcium carbonate, it dissolves more slowly than pure calcitic lime, which produces a more stable, longer-lasting pH correction.
Calcium strengthens cell walls, aids root development, and is involved in cell division. It also improves soil structure in clay soils by flocculating (clumping) fine particles to improve drainage and aeration.
Magnesium is the central atom of every chlorophyll molecule and is required for activating over 300 plant enzymes. Without sufficient magnesium, plants cannot photosynthesize effectively — shown as interveinal chlorosis (yellowing between leaf veins) on older leaves.
The carbonate component is the pH-raising agent. It reacts with soil acids to form carbon dioxide and water as byproducts — a clean neutralization reaction with no residual chemical burden on the soil.
Calcitic lime provides only calcium. Dolomite addresses both calcium and magnesium in a single application — the right choice when soil tests show deficiency in both, or when magnesium levels are borderline.
Magnesium carbonate dissolves more slowly than calcium carbonate. This makes dolomite more forgiving — less likely to overshoot target pH — and extends the period of effective soil buffering.
High calcium without adequate magnesium can suppress magnesium uptake through cation competition. Dolomite's balanced ratio helps maintain an appropriate Ca:Mg ratio in the soil exchange complex.
Timeline assumes adequate soil moisture and temperatures above 50°F. Sandy soils react faster; clay soils require more time and higher application rates.
| Application Area | Rate | Frequency | Notes |
|---|---|---|---|
| Garden Beds — Sandy Soil | 2–4 lbs/100 sq ft | Test after 6 months | Light soils need less |
| Garden Beds — Clay Soil | 8–10 lbs/100 sq ft | Test after 6 months | Heavy soils need more |
| New Gardens | 5–10 lbs/100 sq ft | 3–4 weeks before planting | Test soil first |
| Lawns | Match annual fertilizer | Once in winter | Balances fertilizer acidity |
| Fruit Trees | 5–8 lbs per tree | Annually if needed | Broadcast under drip line |
| Flower Beds | 3–5 lbs/100 sq ft | Test after 6 months | Avoid acid-loving plants |
| Current pH | Target pH | Dolomite per 100 sq ft | Time to Effect |
|---|---|---|---|
| 4.0 | 6.5–6.8 | 12 lbs | 3–6 months |
| 4.5 | 6.5–6.8 | 10 lbs | 3–6 months |
| 5.0 | 6.5–6.8 | 7 lbs | 2–4 months |
| 5.5 | 6.5–6.8 | 5 lbs | 2–3 months |
| 6.0 | 6.5–6.8 | 2–3 lbs | 1–2 months |
Refer to the Safety Data Sheet (SDS) for complete safety information.
Dolomite lime corrects pH and supplies calcium and magnesium — pair it with these amendments for a complete soil health program.
Adds calcium and improves soil structure without raising pH — ideal for soils that need calcium but are already at target pH.
pH DownLowers soil pH for acid-loving plants like blueberries and azaleas. Use when pH is too high rather than too low.
OptionalFast-acting, water-soluble magnesium for foliar or soil application when immediate correction is needed without pH adjustment.
Dolomite lime is a naturally occurring limestone that contains both calcium carbonate and magnesium carbonate, giving it 22.7% calcium and 11.8% magnesium. Regular calcitic lime is composed almost entirely of calcium carbonate — it raises pH faster but supplies only calcium. Dolomite is slower-acting and the better choice when a soil test shows magnesium deficiency alongside low pH. Learn more in our article The Helpful Benefits of Dolomite Lime in Your Garden.
The best time to apply is in fall, giving the lime a full winter to react before spring planting. At minimum, apply 3–4 weeks before planting. Spread evenly, work into the top 6–8 inches of soil, and water thoroughly. Always test pH first to determine the correct rate, and retest after 3–6 months to evaluate the effect.
Pro tip: Split applications over 50 lbs per 1,000 sq ft into two treatments spaced 6 months apart to avoid overshooting the target pH.
Plants that prefer a near-neutral pH (6.0–7.0) are the best candidates: brassicas (cabbage, broccoli, kale), beets, asparagus, spinach, apple and cherry trees, most lawn grasses, and flowers like clematis and delphiniums. For more on calcium's role in plant health, see our article Best Calcium Fertilizer for Your Garden.
Acid-loving plants such as blueberries, azaleas, rhododendrons, potatoes, and hydrangeas (for blue flowers) require or prefer lower soil pH (4.5–5.5) and may not be well-served by liming. Sensitivity varies by cultivar and growing conditions — check your specific plant's pH preference before applying.
Magnesium deficiency typically appears as interveinal chlorosis — yellowing between the leaf veins while the veins themselves stay green — usually on older, lower leaves first. It's common in sandy soils, heavily leached soils, or soils that have received repeated high-calcium applications without magnesium. Dolomite's 11.8% magnesium content can help correct the deficiency over several months. For an immediate response, combine with fast-acting Epsom Salt as a soil drench or foliar spray. Learn more in What's the Function of Magnesium (Mg) in Plants? and 8 Reasons Why Your Plant's Leaves Are Turning Yellow.
Yes. Sprinkle 1–2 cups per cubic foot between layers as you build the pile. Dolomite neutralizes the acidic byproducts of decomposition, reduces sulfur odors, speeds microbial activity by maintaining a better pH environment, and adds calcium and magnesium to the finished compost. For more on how soil pH and soil life interact, see How Soil Microbes Affect Plant Health.
Yes. Over-liming is a real risk. Raising soil pH above 7.5 can lock out manganese, boron, iron, and zinc — creating deficiencies even in soils that have adequate levels of those nutrients. Always apply based on a soil test result, never guess, and retest before reapplying. If you suspect you've over-limed, Elemental Sulfur can be used to lower pH back toward the target range.
If you're not completely satisfied with your purchase, return the unused portion in its original packaging within 90 days for a full refund — no questions asked.
1% of all profits go to our foundation, focused on improving educational opportunities for children.
Family-owned since 1989, Greenway Biotech has been making gardens — and their growers — healthier for over 35 years. We manufacture our products at our facility in Madera, California, and stand behind every bag we ship.
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