One of the biggest problems I see in gardens are plants dying or at the very least failing to grow because they are surrounded by weed mat. I now routinely recommend to my clients to remove weed mat in their garden beds and once I explain why, most are happy to do so.
1 / Compacted Clay Soils
Most gardens on Auckland’s North shore have a clay soil type. Clay soils are often berated for getting waterlogged, causing root infections for plants and being difficult to dig – all of which are true. When weed mat is put on top of a clay soil and then heavy pebbles or stones placed on top of that, the soil becomes compacted and hardened. This can lead to anaerobic and waterlogged conditions during wet conditions, which then causes plant roots to rot and die.
2 / Barrier To Growth
When trees and shrubs are planted through weedmat, their growth can be obstructed by the matting around their base. In addition, you are unable to feed the plant or the soil with a granular fertiliser or sheep pellets as these products can't access the ground, due to the weedmat being a barrier to growth.
3 / Mulch, mulch, mulch
So if not weed mat, what else? Firstly, keep on top of weeds by pulling them when they are tiny. Secondly, lay a good 3 inches of forest floor mulch over your garden. It is every bit as effective as weed mat, keeps soil from drying out, (so reduces the need for watering, especially in summer) and allows your soil to enjoy the benefits of the mulch slowing breaking down, adding organic matter to your soil and releasing the nutrients your plants need to thrive.
4 / Worms Are Our Friends
If you lay weed mat in your garden beds, you stop the natural cycle that keeps your soil healthy. When plants are growing in soil that is constantly enriched by organic matter in the form of fallen leaves, wood chip mulch, compost, manure etc., worms are attracted into the soil where they aerate the earth (essential if you have clay soil) and leave behind their castings. Worm casts hold moisture, which means less watering and the soil stays lighter and fluffier. The soil’s microorganisms also thrive, breaking down the mineral matter into the nutrients that plants need to grow.
5 / Perfect for Pebble Pathways
Weedmat is perfect under aggregates like pebbles & shells in areas where plants aren't growing.
So, pull up the weed mat in your garden beds, add some garden mix, lay some mulch and watch your garden grow.