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does bark stop weeds growing

Yes! Bark protects the soil and any plant roots from summer drought and the full force of thunderstorms. It also provides a layer of insulation, which means that the soil and any plant roots are less likely to succumb to the effects of fluctuating temperatures throughout the year – which is what can cause plants to “heave” out of the ground. When the bark eventually decomposes, it releases a range of nutrients and organic matter that enrich the soil below, and enhance its fertility.

Regulates Soil Temperature – Bark acts as a layer of insulation, protecting the soil and any plant roots from weather fluctuations throughout the year.

How long does bark last; when will it need replenished?

Bark protects trees from attack throughout their life and accordingly has a diverse range of organic compounds in its make-up. ‘Terpenes’ are one particular group of compounds in fresh bark that are known to have an adverse effect on plant growth. Therefore, if fresh bark is incorporated into soil adjacent to plant roots, the plant may be affected by Terpenes.

Bark’s weed suppression capacity arises purely as a result of the physical barrier it creates – depriving weeds of the sunlight they need to grow. Weed seeds land on the mulch surface and are washed down to the soil by rainwater. As they try to germinate on the soil surface, the shoot is deflected underneath the bark where it runs out of vigour and dies. The coarser the bark, the greater its weed suppression capacity.

When is the best time of year to apply bark as a mulch?

Suppresses Weed Growth – Bark shades weed seeds from the sunlight they need to grow, and allows your desirable plants to receive the soil, water and nutrients they need – without undue competition.

Does bark stop weeds growing

When used correctly before weeds sprout in early spring, pre-emergent herbicides are one effective way to prevent weeds coming up in mulch. They won’t, however, do anything for weeds that have already sprouted.

Mulch acts as physical barrier against weeds, but it must block sunlight in order to be effective. If you notice weeds coming up in mulch, you may need to thicken the layer as blocking light generally requires at least 2 to 3 inches (5-7.6 cm.). Replenish mulch as it decomposes or blows away.

Manual Mulch Weed Control

Sometimes, good old hand-pulling is still the most effective way of getting rid of weed growth in mulch.

Other than hand-pulling, mulch is probably the single most important means of weed control. However, mulch works best when used as part of a multi-pronged approach along with pre-emergent herbicides.

Getting Rid of Weed Growth in Mulch

To stop weeds in mulch with pre-emergent herbicides, begin by raking mulch off to the side, then hoe or pull any existing weeds. Apply the product, following manufacturer directions to the letter. Pay attention to the label, as some plants don’t tolerate certain types of pre-emergent herbicides.