Lars Lund

08 Sep 2020 14:33

Seed Compost

Giving your seeds the best start is crucial to germination success and key to that is using the right compost.

Seed compost is finely textured, unlike multipurpose compost which can have relatively large pieces of organic matter in it. Seed compost is also low in nutrients which is important as some seeds can be damaged by high levels of nutrients. Seeds also don’t need nutrients in order to germinate as all the food and energy they require in order to sprout is contained within the seed. Some seed composts come with added vermiculite or perlite which absorb water, releasing it as the compost dries out. Seedlings grown in seed compost will need to be pricked out and potted on when they have two sets of leaves as there won’t be sufficient nutrients in the compost to sustain growth.

For many seeds a good quality multipurpose compost is a good compromise. For tiny seeds it’s a good idea to sieve the compost before filling seed trays and pots so that any large pieces of compost are removed. Adding some perlite will also help to improve drainage. For larger seeds like sweet peas and beans, which need to be sown into large pots, multipurpose compost is the best choice, as it means the seedlings can stay in their pots for much longer and they’ll have the extra nutrients that the seed compost wouldn’t provide.

Don’t be tempted to use home-made compost as this is likely to be full of weed seeds, and you won’t be able to tell the difference between a weed seed and the seeds you actually sowed!

You should look for peat-free compost, as extraction of peat from bogs across Europe is damaging an important ecosystem and also releasing huge amounts of carbon into the atmosphere, contributing to climate change. Check the packaging – if it doesn’t mention it’s peat-free it’s likely it contains at least some peat.

Om Lars Lund

Lars Lund
Danish horticulturist and journalist
Lars Lund has for many years engaged in the garden and greenhouse. Lars has published many books about greenhouses, and he has participated in many Danish horticultural TV shows. He is a walking garden encyclopaedia, and he has answers for most basic cultivation questions – also the more ambitious ones.  

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