Should I plant my seedlings in gardening topsoil or compost? (2024)

FAQs

Should I plant my seedlings in gardening topsoil or compost? ›

Any standard gardening project will require topsoil in order for your seedlings to flourish.

Seedlings are tiny and delicate and therefore need a light compost that they can push through as they emerge from their seed. Anything too heavy will smother the seedlings before they've had chance to surface. This leads to poor germination rates and unhealthy plants.

Combine compost, topsoil, a bit of coarse sand, and something like vermiculite, perlite, or coco coir until you have a mix with a consistency that holds together when wet. For seed starting, you'll avoid using as much sand as you would when making soil for your garden.

Compost can dry out quite quickly, so mixing it with topsoil is a great way to provide balanced bedding for plants and flowers. You get the best of both worlds with a mixture since topsoil will offer a robust home for roots with plenty of water, while compost will provide a boost of nutrients.

Creating new garden beds: Topsoil is often used to create new planting areas or to expand existing ones. It provides a nutrient-rich base for plants to grow in. On its own, topsoil is not a great growing medium and I would recommend mixing in compost.

Will Seeds Germinate in Pure Compost? Some compost isn't decomposed into its humus state yet, isn't made of all the right ingredients, and could be a little smelly. This isn't the stuff you want to use to start your seedlings because it could be too potent for the seeds and burn them.

Use wide, flat containers to avoid overcrowding

Good drainage is essential. Plastic pots or containers are preferable to clay pots when starting seeds, as they retain moisture more consistently.

Mix the ingredients

A mixture of 70% garden soil and 30% organic matter creates a good general potting mix for planting up trees, shrubs, perennials and fruit. If your garden soil is heavy, reduce the soil content by around 10% and add some sharp sand, grit, or bulky organic matter in its place to improve drainage.

Topsoil contains beneficial soil microbes that aid nutrient availability and uptake. But the soil is coarse and heavy, owing to its composted matter, clay, and rock particles. This means that although topsoil is fertile, its properties, like low drainage and aeration, aren't suitable for plant growth.

You can mix compost with topsoil to create your own potting compost, as many of the nurseries do, which gives you the advantages of soil – namely that it dries out more slowly and holds its structure better – together with the benefits of compost – organic matter and more nutrients, a compost made with loam or soil is ...

Can I plant in compost only? ›

Growing plants in pure compost can cause problems with water retention and stability as well. When mixed with topsoil, compost works wonders with water, as it allows good drainage through heavy soil while it retains water in sandy soil. Used on its own, however, compost drains quickly and promptly dries out.

Compost – Promotes Healthier Plant Growth. Compost is most well-known for its contribution to healthy and resilient plant growth. It has a number of complementary benefits to plant growth, among them that it balances soil density, adds and retains nutrients, and discourages disease, pests and weeds.

Seeds need sterile, lightweight, moisture-retaining soil that is also well-draining. I recommend E.B. Stone Organics Seed-Starter Mix.

The process of seed germination can be carried out without soil. For a seed to grow, mature, and germinate it requires some important factors. If the same nutrients are provided in an artificial medium, a seed can very well germinate without soil also. Thus, seeds can grow without soil.

Add Compost: Mix in compost, coco coir, or worm castings to provide additional nutrients for seedlings. Aim to add about 20-30% compost by volume. Combine Thoroughly: Thoroughly mix the ingredients until well blended. Break up any clumps and ensure an even distribution of materials.

Coir and perlite mixes make the best seed compost for your garden seedlings. Perlite is recommended as a growing medium for seeds and cuttings as it provides aeration and speeds up propagation. Coir helps with water retention for healthy roots and is environmentally friendly as it is recycled from coconuts.