09:28 - 04 March 2011
Seeds will germinate in a variety of growing media, even in the garden soil in the right conditions. But when you are investing a pound or two for a packet of seed and when that packet has the potential to produce a dozen, twenty, fifty or a hundred new plants, it makes sense to give them the very best growing conditions to achieve their full potential. A small pack of seed compost, say 10l, will cost you two or three pounds and be enough to fill about twenty 7 or 8cm pots full of compost. That works out at about 15p a pot. Now ask yourself if it is worth spending an extra 15p to ensure your seeds have everything they need. Most gardeners think it is and that’s why experienced gardeners use dedicated seed compost. But if you buy a large bag and are growing lots of seeds it works out even cheaper.
Do you need seed compost for most seeds?
No, probably a quality multi-purpose compost will do. But for specialist seeds, expensive seeds and rare seeds, it’s worth going the extra mile and giving them the very best start in life. And even for ‘normal’ seeds, it is worth using seed compost, as you will get a higher rate of germination and healthier seedlings because it is formulated to support seedling growth.
Can you use garden soil to grow seeds?
Outdoors, yes probably, except for precious seeds, but in a greenhouse you should not take the risk, that’s because the warmer greenhouse conditions can also nurture fungal diseases in the soil. It may introduce pests into the greenhouse or nurture soil borne problems. That also applies to old and stale compost. Always use fresh, good quality compost in your greenhouse. It’s not worth cutting corners over and any savings will undoubtedly be lost through plant losses.
What’s so great about seed compost?
Seed compost is specially formulated to grow seeds. It’s not a marketing gimmick or a con; it really is different.
It is specially designed to perfectly support the germination and growth of. It’s a worthwhile investment and will improve your success rate.
The most important thing with a seed compost is contact with the seed; seed compost has a fine and consistent texture. This allows moisture to be absorbed by the seed coat and speeds germination.
A seed compost has to be free draining to stop the seeds from rotting and to allow air to circulate both around the seed and then around the developing roots. An open structure allows for easy root penetration and leaf formation.
In a seed compost the nutrient levels are low, this is to stop the delicate young roots from being scorched and damaged.
Most seed composts contain added sand or fine grit to enhance drainage but it is also there to ‘tickle’ the seeds into action and is also important for cuttings. The sand abrades the surface of the seed and weakens the seed coat, which can be important for the germination of some more tricky seeds.
Seed compost is generally free flowing, clean and easy to handle which speeds things up for the gardener and makes it more pleasant to use.
Most seeds will be OK in Multi-purpose compost but you will get consistently better results with a dedicated seed compost and seeds that require a little more TLC will germinate better. A seed compost is the preferred choice of expert gardeners.
A good seed compost also has the exact requirements for cuttings, which also need good drainage, low nutrients and abrasive ingredients making it doubly valuable for gardeners.
