Mulch is a must in organic gardening.

Mulch helps to maintain and promote soil fertility and is incredibly important in your garden, whether it be a simple vegetable bed, amongst flowers, annuals, perennials or under trees.

Mulch benefits to the soil.

  • Breaks down to add nutrients and organic matter to the soil
  • Provides a good environment for earthworms
  • Provides nutrients for soil micro-organisms
  • Promotes soil water retention
  • Reduces leaching of soil nutrients
  • Suppresses weed growth
  • Forms a blanket on the soil to promote a constant temperature so soil micro-organisms can flourish

Mulch benefits to gardeners.

  • Makes tiling of the soil easier – mulch encourages soft and friable soil
  • Reduces weeding – mulch covers areas to suppress weed growth
  • Reduces watering – mulch conserves moisture
  • Reduces the need for fertiliser – mulch encourages soil-organisms to produce nutrients
  • Keeps low growing plants clean – mulch prevents mud splashing on plants

How and when to apply mulch.

bark mulchMulch can be applied all year round and is very important for establishing new gardens.

Spring – When preparing to plant for Spring, cover the entire bed in mulch. Leave a planting hole or opening for  seeds or seedlings and cover the rest of the bed in mulch. In colder regions allow the sun to warm up the exposed soil for 2-3 hours before planting.

Summer – Keep your soil covered in mulch throughout the season. In hot, humid areas mulch breaks down more quickly and should be replenished more often.

Autumn – Empty your garden beds for winter planting and leave the ground bare for a few days to give the birds time to feed on insects and grubs, then mulch entirely.

Winter – Keep the beds covered in a thick layer of mulch to conserve warmth in the soil.

Starting a new garden – Set out the garden beds, weed the area, add rock-phosphate or bone-meal, water and then completely cover the area with mulch. Use up to 10cm thick mulch layer on sandy soil and no more than 5cm thick on clay soil. You can plant at any time after you’ve mulched. Add layers of mulch when it is absorbed into the soil.

Under trees – Always leave a hand’s length between the stem of a tree and the mulch – this allows ventilation and prevents fungal disease from developing against the stem of the tree.

Mulch helps to keep your garden water-wise.

mulch bedMulch prolongs soil moisture – a blanket of mulch will shade the ground from the hot sun reducing evaporation. It also helps reduce the impact of heavy rain and allows the water to filter gently into the ground. Compacted, bare soil does not absorb water easily and applying mulch prevents soil compaction and erosion. Adding mulch to your garden beds is a simple and easy step in moving towards a water-wise garden.

Mexican Bush Sage.

salvia leucantha flowersSalvia leucantha, better known as Mexican Bush Sage, is a great addition to any garden – it’s water wise needing only sporadic watering and it can even resist a drought. Remember, that because Salvia leucantha is drought-resistant it likes full sun and well drained soil, it tends to get lanky after too much watering.

Salvia leucantha grows into 1.5m-tall clumps with a spread of 80cm or more. This shrub has spikes of woolly, purple bracts and mauve-white flowers and blooms from late summer or autumn and into winter.

There are many different cultivars of Salvia leucantha; ‘Midnight’ has rich purple spires of velvet flowers on silvery stems above woolly leaves and new cultivars ‘Velour White’ and ‘Velour Pink’ have recently been released.

Late June is the time to prune.

It’s best to prune Mexican Bush Sage in June as this is when new growth appears. The shrub must be pruned hard when you see that the new ‘white’ shoots are about 10-15cm high.

The older woody branches should be cut to ground level, but the new growth that is emerging from the centre of the plant should be left, as this is what will continue to grow.

If you see that the new white shoots are not stiff enough to stand by themselves, then you’ve left your pruning a bit too late. The best solution is to lightly prune the shoots to encourage new growth.

A great tip to keep in mind is that when you prune, it’s easier to work from one side of the plant to the other, this is so you can reach right to the bottom on the stems.

Step-by-step guide.

Salvia leucantha

1. Salvia before pruning

Salvia leucantha

2. Old and new growth

Salvia leucantha
3. Correct height of new growth
Salvia leucantha
4. Prune from one side to the other
Salvia leucantha

5. Completed pruning

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