Light compost with peat and perlite

Regular price $12.00
Regular price Sale price $12.00
Volume Price Price per L vs 25 L
25 L $12.00 $0.48—
50 L $22.00 $0.44−8 %

Plagron Lightmix is a light, lightly fertilised potting compost, aerated with fibres and perlite. Its low conductivity encourages rapid rooting of young plants and cuttings, and its one-week fertiliser charge leaves control of nutrition to the grower, who then doses their own liquid fertiliser.

Ref. TK-PLAG-LIGHTMIX-25·Growing medium
Volume : 25 l
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The summary

  • Mix: a compost of peat, fibres and 10% perlite, pre-fertilised for one week.
  • Starting salts: a low conductivity of 1.1 mS/cm, for roots that get off to a quick start.
  • Typical use: young plants, rooted cuttings and crops fed with liquid fertiliser.
  • Fertiliser handover: after the first week, with a soil fertiliser such as Terra Grow.

An airy, lightly fed potting compost, so you can manage the nutrition yourself

Plagron Lightmix is a light potting compost of peats, fibres and 10% perlite, pre-fertilised for one week, with a conductivity of 1.1 mS/cm. It takes young plants and rooted cuttings, and then Terra Grow takes over. It stays in the pot, out of the aquaponic bed. It is the least nutrient-rich of the three composts in the range.

A very rich compost feeds the plant in your place for weeks, but it leaves no room to fine-tune what the plant receives. Lightmix takes the opposite approach. This light compost contains only a small charge of mineral fertiliser, enough to last a week, and then leaves the grower to decide on nutrition with the liquid fertiliser of their choice. You use it for pricking out young plants, potting up rooted cuttings or filling pots that you will feed yourself, in 25 or 50 L bags.

The mix combines peat, various fibres and perlite, very light mineral grains that drain excess water and keep air between the particles. Its low conductivity, at 1.1 mS/cm, indicates a small quantity of dissolved salts, which is gentle on young roots and encourages rapid rooting. Its pH, between 5.9 and 7, lies within the range where most vegetables absorb their nutrients best. As the compost contains neither humus nor organic fertiliser, its reserve dissolves quickly and is not replenished, which gives you a stable and predictable base.

🧪 A minimal fertiliser charge

Pre-fertilisation is limited to 1.5 kg of mineral fertiliser per cubic metre, with an NPK 12-14-24 formula, which comes to 1.5 g per litre of compost and about fifteen grams in your 10 L pot. This fertiliser dissolves with the first waterings, so its elements are available immediately, then used up after about a week. It is the same formula as that of Growmix, dosed a little higher to last three weeks. Beyond this first week, it is you who decide what the plant receives, watering after watering, according to its stage and its vigour.

Young plants

Seedlings that have been up for one to two weeks can be pricked out straight into it, in a medium that protects their roots.

Controlled cultivation

This almost neutral base is fed at your own pace, with a liquid fertiliser dosed at each watering.

Repotting

Its lightness suits plants transferred into pots, planters or fabric pots on a balcony.

An EC tester for dosing liquid fertiliser

With only one week of reserve, Lightmix needs a liquid fertiliser from the second week, and it is the conductivity that tells you whether the dose is right. The ARKA myAqua pH, EC and TDS tester measures the watering solution before it is applied, then the water draining from beneath the pot. You increase the dose gradually as the plant grows, without risking a build-up of salts in a compost that contained almost none.

Rinse the plug when the drainage water becomes too salty

A mineral fertiliser dosed too strongly builds up in the potting compost, and the roots then suffer from an excess of salts, with leaf edges turning brown. If the conductivity of the water draining from the pot is clearly higher than that of your watering solution, water once with plenty of plain water, then resume the fertiliser at a lower dose.

After the first week, nutrition is delivered entirely through watering. A growth fertiliser for soil, such as Terra Grow, supports the development of the foliage, then a flowering fertiliser such as Terra Bloom takes over on tomatoes, peppers or strawberry plants as soon as the first flowers appear. The 100% TERRA growing scheme even starts Terra Grow at half dose from the first week. The compost was designed for mineral nutrition, which requires regularly checking the pH and conductivity of the solution, but a liquid organic fertiliser can also be used once the mineral charge is exhausted. In that case, allow about two weeks before its elements become available to the plant, and start the applications accordingly.

🌱 Lightmix and the aquaponic nursery

Lightmix is a potting compost, and it never goes into the circuit of an aquaponic system: its fine peat particles would cloud the water, clog the filters and add a mineral fertiliser that the fish should not receive. The grow bed is filled with clay pebbles or another inert grow medium, and seedlings intended for the system's net pots are best raised in an inert support, such as germination pods or rockwool. A plant you have raised in compost can still join the system, provided you gently rinse its root ball under a trickle of water until only the roots remain, before installing it in the pebbles.

Around the system, the poorness of Lightmix becomes an advantage. Potted plants that you water with the water changed from the tank already receive the nitrate produced by the fish, and a nearly neutral compost lets you measure exactly what this water gives them. Aquaponic water, however, remains low in potassium and iron, the most common deficiencies in aquaponics, so a complete flowering fertiliser for soil usefully supplements fruiting vegetables grown in pots. The article on plant deficiencies in aquaponics helps you recognise these shortfalls on the foliage.

🪴 Transplanting and repotting

Moisten the potting mix before filling the small pots or planters, because dry peat repels water at first. Then make a hole with your finger, set your young plant a little deeper than it was, then firm lightly around the base of the stem and water at the foot. Tomatoes tolerate being buried up to their first leaves, which makes them form roots along the stem. A fabric pot complements the lightness of the mix well, since its walls let the roots breathe and stop them from circling against the plastic.

The 25 L bag fills about fifty half-litre pots for a batch of transplanting, or eight 3 L pots for herbs. The 50 L bag fills four 12 L pots for tomatoes or a row of planters on a terrace. Reseal an opened bag and store it somewhere dry, out of the sun, while compost that has already been used can be sieved at the end of the season to remove the roots, then mixed with fresh compost before being used again.

Technical specifications

The product

Composition
Black and blonde peat, fibres, perlite10% perlite by volume
Pre-fertilisation
1.5 kg/m³, NPK 12-14-24Mineral fertiliser, used up in about a week
Conductivity
1.1 mS/cm
pH in water
5.9 to 7
Organic matter
82% of the dry matterDry matter equal to 34% of the raw product
Water retention
6 ml per gram of dry matterPerlite retains air pores

Usage

Uses
Young plants, cuttings, potsPlants that have been up for one to two weeks
Nutrition
Liquid fertiliser after the 1st week
Checks
pH and conductivity of the solution
Aquaponic bed
No, intended for pots only

2 further specifications are available in the detailed view.

In the box

  • 1 bag of Lightmix of 25 or 50 L depending on the volume chosen

Composition, analyses and NF U 44-551 standard taken from the French label; perlite, pre-fertilisation and follow-on feeding based on plagron.com.

Manufacturer and product safety

Manufacturer
Bertels B.V.

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

Lightmix ou un terreau plus chargé ?

Le Lightmix est le plus léger des trois terreaux de la gamme ; les deux autres nourrissent plus longtemps.

Lightmix, Growmix ou Royalmix ? Les trois terreaux reposent sur la même base ; seule la réserve d'engrais change, d'une à six semaines.

Engrais incorporéRéserve d'engrais (sem.)Engrais par mètre cube (kg)Formule de l'engraispH dans l'eauConductivité (mS/cm)Plants accueillisRinçage avant plantationPremier engrais liquidePrix
Recommended
Terreau léger à la tourbe et à la perliteYour choice		Minéral, 1 semaine1 sem.1,5 kgNPK 12-14-245,9 à 71,1 mS/cmJeunes plants et boutures enracinéesNoAprès la 1re semaine$12.00
Terreau préfertilisé pour plantation et rempotageYour choiceMinéral, 3 semaines3 sem.1,8 kgNPK 12-14-245,7 à 6,71,7 mS/cmPlants déjà enracinésNoDès la 4e semaine$15.00
Terreau organique fertilisé à l'humus de verYour choiceOrganique, 6 semaines6 sem.10,5 kgNPK 5,5-11-5,56,0 à 7,81,6 mS/cmPlants déjà enracinés, après rinçageYesDès la 4e semaine, organique$19.00
Terreau léger à la tourbe et à la perliteRecommended
Engrais incorporéMinéral, 1 semaine
Réserve d'engrais (sem.)1 sem.
Engrais par mètre cube (kg)1,5 kg
Formule de l'engraisNPK 12-14-24
pH dans l'eau5,9 à 7
Conductivité (mS/cm)1,1 mS/cm
Plants accueillisJeunes plants et boutures enracinées
Rinçage avant plantationNo
Premier engrais liquideAprès la 1re semaine
Terreau préfertilisé pour plantation et rempotage
Engrais incorporéMinéral, 3 semaines
Réserve d'engrais (sem.)3 sem.
Engrais par mètre cube (kg)1,8 kg
Formule de l'engraisNPK 12-14-24
pH dans l'eau5,7 à 6,7
Conductivité (mS/cm)1,7 mS/cm
Plants accueillisPlants déjà enracinés
Rinçage avant plantationNo
Premier engrais liquideDès la 4e semaine
Terreau organique fertilisé à l'humus de ver
Engrais incorporéOrganique, 6 semaines
Réserve d'engrais (sem.)6 sem.
Engrais par mètre cube (kg)10,5 kg
Formule de l'engraisNPK 5,5-11-5,5
pH dans l'eau6,0 à 7,8
Conductivité (mS/cm)1,6 mS/cm
Plants accueillisPlants déjà enracinés, après rinçage
Rinçage avant plantationYes
Premier engrais liquideDès la 4e semaine, organique

Étiquettes françaises (NF U 44-551) et plagron.com.

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Bags of compost are dispatched as parcels from a distributor's warehouse in France. Heavy and bulky, they weigh on the shipping cost, the exact amount of which is shown in your basket.

Frequently asked questions

6 questions

6 key questions

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