Mature Plant Compost

£17.49

JBJIN3

Pack Size: 35L

35L

Product variants

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The perfect pairings

Mature Plant Compost

35L

£17.49

Product Description

Mature Plant Compost

Mature Plant Compost is a nutrient-dense blend, ideal for supporting the needs of established plants, including mature shrubs, trees, climbers, fruit trees, bushes, vines, and vigorous growers like tomatoes and chrysanthemums.
Its high nutrient content promotes strong, sustained growth and vibrant health, while the well-aerated structure supports extensive root development and ensures excellent drainage. This compost helps retain moisture effectively without the risk of waterlogging, reducing the likelihood of root rot. It’s particularly well-suited for long-term potting, providing the ongoing nutrition mature plants require when remaining in the same container for extended periods.

As the richest compost in our range, it delivers triple the nutrient levels found in early-stage composts, making it the ideal choice for plants that demand more as they grow and develop.
Mature Plant Compost offers structure, moisture balance, and high nutrient levels-giving your established plants the best conditions to thrive over the long term.

Features

Feed 6 Months
Filters Moisture
Retains Moisture
PH 5.5-6.0
+ John Innes

Mature Plant Compost

Professional, specially formulated John Innes No. 3 compost designed for mature plants, shrubs, trees and long-term containers. The John Innes No. 3 formulation provides added body for established plants. Six months of feeding is included to support plants after planting. Ideal for potting established plants that need lasting stability, this substantial, loam-based blend helps provide weight and dependable root anchoring, supporting long-term establishment in larger pots and containers.

Perfect for:
Mature Shrubs
Fruit Trees
Ornamental Trees
Established Roses
Bay Trees
Olive Trees
Acers
Large Houseplants
Permanent Containers
Patio Shrubs
Long-Term Planters

FAQs

Please read our FAQs page to find out more.

Does your compost contain pests or fungus?

Fungus gnats are a common frustration with many mass-market composts, but we take plant health seriously. Our compost is professionally screened and stored in a clean environment to ensure it is free from infestations. By choosing our specialised mix, you are making the correct decision to keep your home pest-free while providing your plants with a clean, healthy start.

How will your compost make my crops & plants thrive?

When plants settle in for the long haul, they need more than just a quick snack; they need a powerhouse foundation. Jamieson Brothers John Innes No. 3 is our most nutrient-dense loam-based formula, specifically fortified to sustain mature shrubs, trees, and permanent container displays. With a robust six-month feed built right in, it eliminates the guesswork of maintenance for your garden's heavy hitters. This 35L bag provides the essential weight and structural integrity to keep large plants securely anchored, while offering a slow-release feast that keeps foliage lush and root systems thriving year after year.

Does your compost contain large bits of bark (garden waste) or random seeds?

A common complaint with cheaper alternatives is finding "green waste" or unwanted seeds in the bag. Our Mature Plant Compost is a refined, high-quality medium that is strictly monitored for purity.

You can be confident that you are receiving a consistent, professional-grade product that contains only the nutrients and structure your houseplants need, with no unwanted surprises or contaminants.

What's the structure & consistency of your compost?

Inferior composts can often arrive bone dry or as a fine dust that is difficult to water. Because our mix contains John Innes, it has a much better physical "body" and weight. This helps it retain the correct amount of moisture without becoming waterlogged or dusty. It is easy to handle and provides the perfect air-to-water balance that is essential for the delicate roots of indoor varieties.

Why is this specialised mix a better investment than a cheaper compost?

Buying a “bargain” compost often leads to the hidden costs of buying additional feed, improving the structure or even replacing valuable mature plants. Our Mature Plant Compost is an all-in-one professional solution. With the stability of John Innes No. 3 and a full six months of feed included, you are saving money in the long run while supporting established plants, shrubs and trees.

It is the most reliable choice for maintaining mature plants and long-term container displays.