The Ultimate Guide to Choosing Compost: How to Pick the Right One for Your Veg Garden

Choosing the right compost can feel a bit like standing in a supermarket aisle staring at dozens of bags and wondering which one your plants will actually love. But get it right, and your veggies, herbs, and flowers will thrive like never before. Get it wrong, and your plants might sulk, grow slowly, or even fail to produce. Don’t worry, we’ve got you covered. Here’s your ultimate guide to understanding compost, picking the right type, and knowing what each one does.

Choosing the right compost and composting at home can also help reduce landfill waste by recycling kitchen scraps and garden materials.

Why Compost Matters

Compost isn’t just soil filler. It’s living, nutrient-rich food for your plants. Compost made from organic materials introduces beneficial microbes and organic matter, which are crucial for improving soil health and fertility. A good compost improves soil structure, holds moisture, and provides essential nutrients. Different plants have different needs, so the right compost can make all the difference.

Compost also helps retain moisture and suppress weeds, in addition to improving soil structure and providing essential nutrients.

For instance:

• Vegetables: Thrive in nutrient-rich, well-draining compost.
• Seedlings: Prefer light, airy, and low-nutrient compost to encourage root growth.
• Pot plants: Need a compost that balances moisture retention with drainage.

High quality compost enhances soil structure, promotes healthy root development, and supports healthy soil for robust plant growth. Unlike chemical fertilisers, composting supports a balanced ecosystem and reduces reliance on synthetic inputs. The decomposed organic matter in compost provides nutrient rich soil, supporting plants roots and overall plant health.

The Different Types of Compost

Multi-Purpose Compost

This is your all-rounder. Ideal for flowers, shrubs, and some vegetable seedlings. Multi-purpose compost is often made from organic materials, including green waste compost and garden compost, which contribute to its versatility and sustainability. It’s usually loamy, light, and has a balanced mix of nutrients.

Best for: Potted plants, garden beds, and general use. Multi-purpose compost provides balanced nutrients suitable for a wide range of plants.

Pro tip: Look for one that’s peat-free for an eco-friendly option.

Seed and Cutting Compost

This is the one to reach for when starting seeds or rooting cuttings. For seed sowing, it’s important to use a specific type of compost that is fine, low in nutrients, and often contains sand or grit to support delicate seedling roots. It’s fine, light, and free-draining – perfect for delicate roots.

Using finished compost ensures seeds have a clean, disease-free environment to germinate, as it is crumbly, dark, and free from un-decomposed materials.

Best for: Starting seeds like tomatoes, peppers, and herbs.

Why it works: Seedlings don’t need loads of nutrients at the start; too rich a compost can burn them.

John Innes Compost

A classic choice for gardeners, John Innes is a type of soil based compost and comes in three types: No. 1, No. 2, and No. 3.

• No. 1: Great for seeds and young seedlings.
• No. 2: For potting on young plants.
• No. 3: For established plants and fruiting vegetables like tomatoes and courgettes.

Each John Innes mix has a different soil pH level, making it suitable for specific plant needs, so you can choose the right one to match your plants’ pH preferences.

Why it works: It’s nutrient-rich and has a loam base, which gives excellent drainage and stability for roots.

Ericaceous Compost

This is acidic compost for acid-loving plants like blueberries, rhododendrons, and camellias. Ericaceous compost is specially formulated to create acidic soil conditions, making it ideal for these types of plants.

Best for: Any plant that thrives in acidic conditions.

Tip: Don’t use it for vegetables, they prefer neutral to slightly alkaline soil.

Specialist Vegetable Compost

Some brands offer composts formulated specifically for vegetables. These often include slow-release fertiliser and are ideal for planting out or growing in containers. Specialist vegetable compost is ideal for vegetable gardens, mature plants, and flowering plants, providing the tailored nutrients these plants need to thrive.

Best for: Veg plots, raised beds, container gardening, and container plants, as this compost provides the right balance of nutrients and moisture retention.

Why it works: Extra nutrients support strong growth and better yields.

Peat-Free Compost

If you’re looking to garden sustainably, peat-free compost is a must. Peat-free compost is a type of organic compost produced from sustainable composting systems, using materials like coir, bark, or green waste. This organic matter not only reduces environmental impact but also supports soil health and fertility.

Best for: Anywhere you’d use multi-purpose compost, particularly in pots or seed trays.

Tip: Some peat-free options can dry out faster, so keep an eye on moisture levels.

How to Choose the Right Compost

Choosing the right compost comes down to three main things:

1. Purpose: Are you starting seeds, potting on, or planting out?
2. Plant type: Acid-loving, fruiting veg, or leafy greens all have different needs.
3. Soil condition: Sandy soils benefit from moisture-retentive compost, clay soils from lighter, draining mixes.

Understanding the composting process is also important, as it helps you choose high-quality compost that will best support your garden.

Quick rule of thumb:

• Seeds & cuttings → Seed compost
• Young plants → John Innes No. 1 or 2
• Fruiting plants → John Innes No. 3 or specialist vegetable compost
• General pots → Multi-purpose or peat-free compost

Examples of specialist composts for specific plant needs include mushroom compost (great for improving clay soils and adding nutrients), bulb compost (ideal for planting bulbs in containers to prevent rot), and succulent compost (formulated for cacti and succulents with added sand or grit for drainage).

Making Your Own Compost

Making your own compost is one of the most rewarding ways to boost your garden’s soil health and support healthy plant growth, all while cutting down on waste. Homemade compost transforms everyday garden waste, food scraps, and grass clippings into nutrient-rich compost that your plants will love.

Top Tips for Using Compost Successfully

• Don’t overfill pots: Leave space at the top for watering.
• Check moisture levels: Compost should be damp but not soggy.
• Mix with garden soil: For in-ground planting, mixing compost with soil improves fertility and structure.
• Fertiliser isn’t always needed: Many specialist composts already have slow-release nutrients.
• Build a healthy compost heap: A well-managed compost heap can include composting kitchen scraps such as vegetable peelings and coffee grounds. These materials add valuable organic matter and nutrients to your compost, helping to enrich your garden soil.
• Avoid fresh manure and horse manure: Do not add fresh manure or horse manure directly to your compost heap or garden beds. Fresh manure is too high in nitrogen and can harm plants; it should be well-rotted or composted before use to avoid potential contamination and strong odours.

Compost is like a buffet for your plants, give them the right food, and they’ll reward you with lush growth and delicious harvests. Understanding the differences between seed, multi-purpose, John Innes, and specialist composts is key to a thriving garden. Keep this guide handy next time you’re wandering the garden centre, and you’ll never be unsure about which compost to buy again.