Evaluating Cotton Burr Compost for Rose Beds: pH, Mix, and Amendments

Compost Effects on Soil pH

All composts, including cotton burr, tend to lower soil pH (increase acidity). If your native soil is alkaline (>6.8), this is beneficial. If already acidic, add pelletized lime (not quicklime) to counterbalance.

Ideal Rose Bed Mix

Target 1/3 each: clay, coarse sand, organic matter (compost, manure, shredded bark). pH 6.3–6.8. Test with a $20 meter.

Improving Cotton Burr Compost

• Blend with pine bark or needles (preferred by some rosarians over hardwood mulch).
• Add rock phosphate for long-term phosphorus.
• Incorporate alfalfa meal for nitrogen and growth stimulants.

Use compost as a component, not the sole amendment. Balance is key.