Organic soil improver with bacteria for potting compost

Regular price $23.00
Regular price Sale price $23.00
Size Price Price per kg vs 1.5 kg
1.5 kg $23.00 $15.33—
5 kg $69.00 $13.80−10 %

Startrex is an organic soil improver from Biotabs, to be mixed into potting compost or coco fibre before planting. With an NPK 3-1-2 analysis, it provides humus, fulvic acid, silicon and a high load of beneficial bacteria, at 25 g per 5 litres of growing medium.

Ref. TK-STARTREX-1500·Organic fertiliser
Size : 1.5 kg
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The summary

  • Composition: an organic NPK 3-1-2 soil conditioner rich in beneficial bacteria, with humus and fulvic acid.
  • Ratio: 25 g for 5 litres of potting compost or coco fibre.
  • When to use: at repotting or when preparing the bed.
  • How far it goes: 300 litres of compost with 1.5 kg, 1,000 litres with 5 kg.

A potting compost brought to life by humus and bacteria before planting

Biotabs' Startrex is an organic soil improver, NPK 3-1-2, rich in bacteria and humus. It is mixed into the compost or coco fibre at planting, 25 g per 5 litres, then Orgatrex feeds at watering. The 1.5 kg bucket treats 300 litres, the 5 kg one about 1,000, away from any pond.

Fresh potting mix straight from the bag is often almost sterile: it retains water and holds the roots, but it harbours little of the microbial life that, in garden soil, turns organic matter into food for plants. Startrex supplies it. This certified organic blend combines a gentle fertiliser, rated NPK 3-1-2, humus, fulvic acid, silicon and a high concentration of beneficial bacteria. You mix it into the medium once before planting, and it prepares a living potting mix for the whole crop.

🪣 At potting on, once

Startrex is mixed into the growing medium before planting, at a rate of two tablespoons, or 25 g, per 5 litres of potting compost or coco coir, which works out at 5 g per litre. Your 20 litre pot therefore takes 100 g, and a 200 litre raised garden bed takes one kilo. It is suitable for vegetables, herbs, flowers, shrubs and trees, in pots or in open ground, indoors or outdoors. The humus and fulvic acid improve the medium's retention of water and nutrients, while the bacteria colonise the root zone from the very first waterings.

10 L tub

50 g of Startrex, mixed into the whole volume.

20 L tub

100 g, for a tomato or pepper plant in a pot.

200 L tank

1 kg, for one raised vegetable bed.

🌱 In aquaponics, around the system

Startrex is a soil improver for potting compost: it has no place in the clay pebbles of a grow bed or in the fish water, where its organic matter would decompose uncontrollably and overload the system. It is used around the system, in the compost of the pots where you raise plants before installing them in the beds, and in the pots and trays of the greenhouse. Young plants find a living medium there until their first true leaves, as the FAO guide advises for the nursery stage, then join the system, with the root ball shaken off and rinsed, where the fish waste takes over. The article which fertiliser to use in aquaponics sets out what suits the system and what is best left to the vegetable garden.

A light potting compost to welcome Startrex

Startrex gives its best in a poor growing medium, preferably an organic one, which it enriches without overloading it. The ZeroMix fertiliser-free potting compost, made of blond peat, coir and clay, contains no fertiliser at all: whatever reaches the roots then comes from Startrex and from you alone. Mix in your 5 g per litre at potting-on, and you get a compost that gently feeds the early growth and provides a home for active microbial life from the outset, with no risk of excess salts for young roots.

A poor compost rather than one that is already enriched

Added to a potting compost that is already heavily fertilised, Startrex adds its contribution to that of the bag, with the risk of an excess for young plants. Choose a light or very lightly fertilised compost, keep the product dry and cool, out of reach of children, and never use it in a grow bed or in the water of an aquaponic system.

♻️ Reusing a compost

Your potting compost, if properly managed, does not need to be thrown away after a single crop. The same growing medium can be reused up to four times, provided you remove the roots of the previous crop and replenish it with every cycle, using 25 g of Startrex per pot mixed into the refreshed compost. The pot is then soaked in a Bactrex solution at 1 g per litre and watered very sparingly during the first week, while the soil life gets going again. After a diseased crop, however, send the compost to the compost heap rather than reusing it, so as not to pass the disease on to the next crop.

Startrex forms the first stage of a three-step organic programme, which you can follow in full or in part. The potting compost receives Startrex first, when it is prepared. You then place 5 g of Mycotrex mycorrhizae in the planting hole, in contact with the roots of the plant, and water with a solution of 1 g of Bactrex bacteria and Trichoderma per litre of water. Each product works at a different level, from the whole compost down to the root ball, so that together they establish a complete soil life from the first days of cultivation. For a long crop in a large pot, slow-release organic fertiliser pellets pushed in at the same time add a reserve of nitrogen that the bacteria release gradually.

🧺 In a gravity-fed system

Gravity-watering systems, where each pot draws its solution through a valve, are used with an airy mix: coco fibre or potting compost blended in equal parts with clay pebbles or perlite. The Startrex dosage then follows the volume of the pot rather than the rule of 5 g per litre: 25 g for an 8.5 L pot, 50 g for 15 L and 75 g for 25 L. If you use the XL gravity system with 25 L pots, allow 75 g per pot, mixed into the medium before planting.

Startrex feeds the start of the crop, but its gentle formula is not enough for a tomato or courgette in full fruiting. Orgatrex liquid organic fertiliser, dosed at 5 ml per litre of water at every watering, then takes over during the weeks of growth and production. The 1.5 kg pack treats around 300 litres of potting compost, roughly fifteen large pots, and the 5 kg pack around 1,000 litres, enough to fill several vegetable-garden planters. Reseal the packaging well after use and store it somewhere dry, so that the micro-organisms stay dormant until the next repotting.

Technical specifications

The composition

Analysis
NPK 3-1-2
Inputs
Humus, fulvic acid, silicon
Microbial life
Concentrated beneficial bacteriaDormant when dry, active on contact with water
Certification
Certified 100 % organic

Usage

Dose
25 g per 5 L of grow mediumTwo level tablespoons
Supports
Compost, coir, open groundLight or low-fertility compost
Time
At repotting or planting
Crops
Vegetables, herbs, flowers, shrubs

In the box

  • 1 pack of 1.5 kg or 5 kg of Startrex, depending on the size chosen

Analysis, applications and uses: manufacturer's data sheet (biotabs.nl). Doses, reuse and storage: Biotabs growing guide in French.

Manufacturer and product safety

Website
biotabs.nl

Information provided under Regulation (EU) 2023/988 on general product safety.

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The pack is dispatched as a parcel from a distributor's warehouse in France. The exact shipping cost is shown in your basket.

Frequently asked questions

8 questions

6 key questions, 8 in the detailed view

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