NPG Aroid Formula Premium Aroid Potting Mix

NPG Aroid Formula is our in-house premium aroid potting mix, developed specifically for Philodendron, Anthurium, Alocasia, Monstera, Scindapsus and other collector aroids.

This is the exact mix we use across our personal collection and production plants. It has been refined through real-world growing experience rather than theory, trends or shortcuts.

Designed to balance airflow, drainage, moisture retention and long-term nutrition, this mix supports strong root development, stable growth and resilience across changing seasons and growing environments.

Why We Made It

We wanted a mix that performs consistently in New Zealand conditions, supports sensitive and variegated plants, reduces compaction and root stress, and works reliably for both established plants and acclimated tissue culture.

So we built it ourselves — and we only sell what we genuinely use.

Key Features

Chunky, free-draining structure that maintains excellent oxygenation around aroid root systems.
Balanced moisture retention without staying wet.
Fortified with slow-release nutrition and beneficial additives.
pH-buffered for aroid-friendly conditions.

The result is a forgiving, stable substrate that supports healthy roots and consistent growth over time.

Best Suited For

Philodendron.
Anthurium.
Alocasia.
Monstera.
Scindapsus.
Mature plants and established cuttings.
Acclimated tissue culture.

Ingredients & Their Purpose

Orchid bark provides the chunky structural base of the mix, promoting airflow, preventing compaction and supporting healthy aroid root development.

Coco chips add moisture retention while maintaining air pockets, helping roots stay hydrated without becoming waterlogged.

Pumice improves drainage and aeration while holding micro-pockets of moisture and nutrients for steady uptake.

Perlite lightens the mix and increases oxygen availability, reducing the risk of root rot.

Fern fibre adds natural structure and long-lasting porosity, mimicking epiphytic growing conditions many aroids prefer.

Bio-char supports beneficial microbes, improves nutrient retention and helps stabilise the root zone over time.

Worm castings provide gentle organic nutrition and support microbial activity without overwhelming sensitive roots.

Basalt rock dust supplies trace minerals and micronutrients that support long-term plant health and resilience.

Dolomite lime buffers pH while supplying calcium and magnesium, essential for strong cell structure and root growth.

Silica powder supports stronger stems, improved stress tolerance and overall plant resilience.

Mycorrhizal inoculant encourages beneficial fungal relationships that enhance nutrient and water uptake at the root level.

What We Didn’t Add — & Why

Peat moss was avoided due to its tendency to compact over time and restrict airflow.
Heavy garden soil or compost blends were excluded because dense materials increase water retention and raise the risk of root rot.
Sand was not used as it can settle over time and reduce aeration.
High-strength or fast-release fertilisers were avoided because they can stress sensitive and variegated plants.
Synthetic wetting agents were excluded in favour of natural water balance achieved through proper particle selection.

No fillers or bulk-weight materials are used. Every ingredient serves a functional purpose.

Normal House Growing vs Cabinet / Grow Tent

In typical household conditions with lower humidity, natural airflow and temperature fluctuation, the mix dries down predictably and remains forgiving for everyday care. Water thoroughly, then allow the mix to approach dry before watering again. Always use pots with drainage.

Cabinet or grow tent growing
In cabinets or grow tents with higher humidity, warmth and reduced airflow, the mix retains moisture for longer while maintaining oxygen around the roots. This helps prevent root suffocation commonly seen in dense substrates. Water less frequently than in ambient conditions and ensure some airflow within the enclosure.

Compatible Fertilisers

NPG Aroid Formula is a nutrient-buffered, biologically active substrate. It already contains slow-release fertiliser, calcium and magnesium sources, trace minerals and beneficial biology. Because of this, less is more when it comes to liquid feeding.

Choose gentle, low-salt fertilisers. Apply at reduced strength. Support the mix rather than overpower it.

Growth Technology (GT)

GT Foliage Focus
Primary ongoing feed. Balanced NPK profile with a low salt load and predictable uptake in bark-based mixes. Use at quarter to half strength for regular feeding in both ambient conditions and cabinets or grow tents.

GT Root Zone
Supports root health and recovery during repotting, root stress and tissue culture establishment. Use short-term only for one to two waterings post-transplant.

NurtureSystem PowerGrow

PowerGrow No.1 – Growth
Suitable for light maintenance feeding at quarter strength every two to three waterings.

PowerGrow Root & Shoot
Best used during transplanting, deflasking and root recovery. Intended for short-term use only.

PowerGrow Seaweed or Kelp
A non-nutrient stress support supplement. Use every four to six weeks or as needed, as a soil drench or foliar application.

Not Recommended With This Mix

Bloom or flowering fertilisers, high-phosphorus or PK boosters, cal-mag supplements, frequent organic teas and heavy liquid feeding. These can cause nutrient imbalance, salt build-up and reduced root health in bark-based substrates.

Feeding Philosophy

Great soil does the work. Fertiliser should support it, not overpower it.

Feed lightly, observe your plants, and allow the mix to perform as designed for strong roots, healthy foliage and long-term stability.

The NPG Approach

We don’t chase gimmicks or over-promise results. NPG Aroid Formula is built around consistency, plant health and transparency — the same philosophy behind everything we do at Nelson Plant Guy.

If you ever have questions about suitability, watering or feeding, just reach out. We’re always happy to help