The essential pH amendment for vegetable gardens, container mixes, and soil blocking. Dolomite lime raises soil pH gradually and supplies calcium and magnesium, two nutrients that Pacific Northwest gardens are typically short on. Our heavy rainfall leaches both from soil and container media over time.
 
Unlike agricultural lime, which supplies calcium only, dolomite contains both calcium (~20%) and magnesium (~10%). For vegetable crops, magnesium is the central atom in every chlorophyll molecule, so magnesium deficiency first appears as interveinal yellowing on older leaves and eventually as reduced fruit set and poor flavor. Portland-area soils and container mixes running low on magnesium are extremely common, and dolomite is the simplest fix.
 
Use in soil blocking mix: This is the lime called for in Eliot Coleman's soil blocking recipe. Add ¼ cup per batch when using Sunshine #5 as a base component (it already contains dolomite), or ½ cup per batch when using straight peat moss. Mix into the dry ingredients before adding water so it distributes evenly.
 
Use in container mixes: Add 1–2 tablespoons per 5 gallons of mix. Peat moss and coco coir are both naturally acidic — dolomite brings them into the 6.0–7.0 range where most vegetables absorb nutrients most efficiently.
 
Use in raised beds and garden soil: Broadcast at 5–10 lbs per 100 square feet and work into the top few inches. Apply in fall for best results — it takes several weeks to fully adjust pH.
 
Not for potato growing: Potatoes prefer pH 5.0–6.0 and are prone to scab above that range. For potato grow bags, use gypsum instead — it supplies calcium without raising pH. Both are available in the store.
 
Fine powder grade (#65) for even distribution through dry mixes and accurate small-quantity measurement. OMRI listed for organic production.