Is rubber mulch or wood mulch better for NB flower beds?

Wood mulch is the better choice for New Brunswick flower beds in almost every situation, providing essential soil-building benefits that rubber mulch cannot match while costing significantly less upfront. Cedar or hemlock bark mulch at $45-70 per cubic yard decomposes slowly over 2-3 seasons, feeding the soil organisms and earthworms that keep NB's acidic, often nutrient-poor soils productive. Rubber mulch at $80-120 per cubic yard never decomposes, which sounds like an advantage but actually means it never contributes organic matter to your garden soil.

The soil-building argument is especially compelling in New Brunswick because Maritime soils desperately need organic matter. Whether you are gardening in Fredericton's heavy clay or Shediac's sandy coastal soil, the slow decomposition of wood mulch adds humus that improves water retention, nutrient cycling, and soil structure over time. Rubber mulch sits permanently on the surface, contributing nothing to the soil underneath. After 5-10 years of rubber mulch, the soil beneath it is typically compacted, lifeless, and less fertile than when the mulch was installed — the opposite of what happens under wood mulch.

Temperature is another critical concern for NB flower beds. Rubber mulch absorbs and retains significantly more heat than wood mulch, reaching surface temperatures 20-30°C higher on sunny summer days. While NB summers are moderate, this heat transfers to the soil and root zone, stressing plants during hot spells in July and August. Conversely, rubber mulch provides no meaningful insulation against NB's winter freeze-thaw cycles because it does not trap air the way organic mulch does. Wood mulch's natural air pockets provide genuine insulation that moderates soil temperature swings, protecting perennial roots through NB's -25°C to -35°C winter lows.

Environmental and health concerns surround rubber mulch. It is made from ground-up recycled tires, which contain zinc, cadmium, and other heavy metals that can leach into soil and groundwater over time. While the research is still evolving, many NB gardeners prefer not to introduce tire components into their food or flower gardens. Rubber mulch is also flammable — once ignited (from a discarded cigarette or nearby fire), it burns intensely and is extremely difficult to extinguish, producing toxic smoke.

The one legitimate use case for rubber mulch in New Brunswick is playground surfaces, where its cushioning properties reduce injury from falls and its permanence means it does not need regular replacement in high-traffic areas. For flower beds, ornamental gardens, and around trees and shrubs, stick with natural wood mulch. Cedar mulch offers the best pest resistance and longevity, hemlock bark provides the richest colour, and hardwood mulch at $35-50 per yard is the most economical option if you do not mind refreshing it annually. Apply any wood mulch 2-3 inches deep, and keep it away from plant stems and tree trunks to prevent rot.

---

Find a Landscaping Contractor

New Brunswick Landscaping connects you with experienced contractors through the https://newbrunswickconstructionnetwork.com:

• Lawrence Landscaping ✓
• Curb Appeal Construction & Landscaping ✓
• Leger Steel Roofing ✓