Martins Native Planting Mix is suitable for growing natives and low phosphorous tolerant plants. It may be used in pots as a potting mix or in the ground as a planting mix. Martins Native Planting Mix is low phosphorus and is a free draining mix which means that it will provide your plants with the best possible growing conditions. This mix contains a controlled release fertilizer for up to 9 months plant growth, add a low phosphorus or native fertilizer as this period nears completion.