The Best Plants for Soil Blocking

December 18, 2025

Soil blocking is one of the most effective ways to start seeds, eliminate transplant shock, and grow healthier seedlings. Many plants respond particularly well to soil blocks, but some benefit more than others. Below is a guide to vegetables, herbs, and flowers that thrive when started in soil blocks. This is by no means an exhaustive list, but it’s a great starting point for gardeners of all levels.

Vegetables That Thrive in Soil Blocks

Many vegetables benefit from air-pruned roots, making soil blocks an ideal way to grow them. Some examples include:

• Tomatoes – develop strong root systems and transplant easily

• Peppers & Chilli – thrive in compact blocks before moving outside

• Leafy greens – lettuce, kale, spinach, chard

• Brassicas – cabbage, broccoli, cauliflower, Brussels sprouts

• Herbs grown as greens – parsley, coriander, basil

• Root crops for transplanting – beetroot, celery, celeriac (small blocks are best)

• Other vegetables – aubergine, pak choi, chicory, endive

Tip: For larger seedlings, use bigger blocks to support longer growth indoors before transplanting.

Herbs That Work Well in Soil Blocks

Herbs are particularly suited to soil blocks because most are slow to establish roots and benefit from air pruning. Examples include:

• Basil

• Parsley

• Coriander / Cilantro

• Thyme

• Oregano

• Chives

• Sage

Starting herbs in soil blocks helps seedlings develop dense root systems, which improves survival rates when moved outdoors.

Flowers for Soil Blocking

Flowers also respond well to soil blocks, especially annuals and perennials that transplant easily. Examples include:

• Sweet peas

• Marigolds

• Cosmos

• Zinnias

• Sunflowers (small seedlings)

• Petunias

• Pansies

• Calendula

Tip: Tiny flower seeds work well in micro soil blocks like the Micro 20, and can then be transplanted into larger blocks using our cube inserts, but make sure the soil is fine and free of clumps.

Quick Tips for Choosing Plants

• Use smaller blocks for tiny seeds (e.g., microgreens, small flowers)

• Use larger blocks for vegetables or slow-growing seedlings that stay indoors longer

• Avoid transplanting root crops that do not tolerate it well (e.g., carrots, parsnips) – they are better direct sown

Final Thoughts

These lists are a starting point, not a complete guide. Many more vegetables, herbs, and flowers can thrive in soil blocks. Experimenting with different plants and observing root development is part of the fun of soil blocking.

With the right soil mix and a bit of practice, soil blocking can dramatically improve seedling health, transplant success, and overall gardening satisfaction.

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