Mulching Raspberry Canes

Why Raspberries Need Mulch

Raspberries have a shallow, fibrous root system that spreads just below the soil surface. This makes them particularly vulnerable to two things: drought stress and weed competition. Without mulch, you’ll spend the growing season hand-weeding around delicate canes and watering constantly during dry spells.

The Weed Problem in Raspberry Beds

Raspberries present a particular weeding challenge because:

• You can’t hoe easily. The shallow root system means any hoeing or digging risks severing feeder roots. Hand weeding is the only safe option without mulch
• Chemical weed killers are risky. Most weed killers can damage raspberry canes through root uptake or spray drift. Glyphosate in particular is absorbed through green stems and suckers
• Canes create shade gaps. The vertical growth habit lets plenty of light reach the soil surface, which is exactly what weeds need to thrive
• Raspberry suckers complicate things. Desirable new canes and unwanted weeds can look similar when small, making hand weeding slow and error-prone

The solution is prevention through mulching. A thick organic mulch layer stops most weeds before they start, and any that do emerge are far easier to pull from loose mulch than from bare soil.

Best Mulch Materials for Raspberries

Avoid using landscape fabric around raspberries. The suckers and shallow roots grow into the fabric, making it almost impossible to remove later. Organic mulch that decomposes and can be topped up annually is a far better long-term strategy.

How to Mulch Raspberry Canes

Here’s the step-by-step method for mulching an established raspberry bed:

1. Weed thoroughly first. Remove all existing weeds by hand. For badly overgrown beds, carefully spot-treat weeds between canes, keeping any spray well away from green stems and suckers. A strong weed killer applied precisely with a paintbrush can deal with persistent weeds without affecting the canes
2. Feed the soil. Before mulching, scatter a general-purpose fertiliser or spread a thin (3cm) layer of garden compost around the base of canes. The mulch layer on top will lock in these nutrients
3. Apply mulch 8–10cm deep. Spread wood chip, bark or straw evenly across the entire bed. Cover the soil between and around all canes, extending at least 30cm beyond the outermost canes on each side
4. Keep clear of cane bases. Pull mulch back 3–5cm from the base of each cane. Direct contact can encourage cane diseases like spur blight, particularly in damp conditions
5. Top up annually. Most organic mulches decompose significantly over a single growing season. Top up in early spring (February–March) before new growth starts. See our mulch application timing guide for more detail

Mulching New Raspberry Plantings

If you’re planting new raspberry canes, mulching at planting time gives them the best possible start:

• Prepare the row. Clear weeds from a strip at least 60cm wide. For new beds on grass, lay cardboard over the grass and cut planting holes through it
• Plant at the correct depth. Set canes so the soil mark on the stem sits at ground level. Firm in well and water thoroughly
• Mulch immediately. Apply 8–10cm of bark or wood chip across the entire planting strip. This suppresses any remaining weed seeds and retains the moisture new canes need to establish
• Leave room for suckers. In the first year, new suckers will emerge from the root system. Mulch helps control where these appear but allow room for the row to fill in naturally

Seasonal Mulching Calendar

Results: Mulched vs Unmulched Raspberries

The difference between mulched and unmulched raspberries is dramatic after the first full season:

• Fruit yield: Studies show mulched raspberries produce 20–40% more fruit by weight than unmulched plants, primarily due to consistent moisture during fruit development
• Berry size: Individual berries are larger and juicier when plants aren’t drought-stressed
• Cane vigour: Mulched canes grow taller and produce more fruiting laterals
• Maintenance time: Weeding drops from hours per week to minutes. Time saved can be spent picking fruit instead
• Soil health: After several years of annual mulching, the soil becomes dark, crumbly and full of earthworms — the ideal conditions for long-term productivity

Frequently Asked Questions

Can I use fresh wood chip around raspberries?

Yes, but with a caveat. Fresh wood chip can temporarily lock up nitrogen as it decomposes. To counteract this, apply a nitrogen-rich fertiliser beneath the wood chip layer before mulching. Alternatively, use composted bark which has already been through the nitrogen-hungry decomposition phase. For raspberries specifically, the slight nitrogen drawdown is rarely a problem because the mulch benefits far outweigh this temporary effect.

How do I deal with raspberry suckers spreading through mulch?

Thick mulch actually helps control unwanted sucker spread. Suckers that emerge beyond the row are weaker when growing through deep mulch and easier to pull out. For really invasive varieties, install a physical root barrier (buried plastic or metal edging 30cm deep) along the row edges, then mulch as normal within the row.

Should I mulch autumn-fruiting raspberries differently?

The mulching approach is identical for both summer and autumn-fruiting varieties. The only difference is timing: autumn-fruiting varieties are typically cut to ground level in February, which is the perfect time to weed and top up mulch before new canes emerge. You get a completely fresh start each year.

Will mulch encourage raspberry cane diseases?

If applied correctly (keeping a small gap around cane bases), mulch does not increase disease risk. In fact, by reducing soil splash during rain, mulch can actually reduce the spread of soil-borne fungal diseases like raspberry root rot. The key is good air circulation — don’t let mulch pile up against cane stems.

How much mulch do I need for a raspberry row?

A 3-metre row mulched 60cm wide and 8cm deep needs approximately 150 litres of material — roughly three standard bags of bark mulch. For larger patches, buying in bulk (loose delivery by the cubic metre) is far more economical. One cubic metre covers about 12 square metres at 8cm depth.

Can I use coffee grounds around raspberries?

Coffee grounds can be mixed into the mulch layer as a nitrogen supplement, but don’t use them as the sole mulch material. Raspberries prefer slightly acidic conditions (pH 6.0–6.5), and while used coffee grounds are nearly neutral, they’re a useful addition to the overall mulch mix. Scatter a thin layer and cover with bark or wood chip.

You might also find it helpful to read about a glyphosate-based weed killer.

You might also find it helpful to read about persistent weeds like couch grass.

You might also find it helpful to read about when to apply weed killer.