Here is another post in my ongoing experiment to learn first hand the best way to raise vegetable seedlings. So what is the best seedling mix? But first lets clarify what I mean by ‘seedling mix’, I mean the soil used to sustain an infinite plant, not the material used to germinate seeds. They are very different and I have written previously about the best seed starting mix.
I tested 8 different mixes each on a set of 4 different plants - broccoli, lettuce, beetroot and spinach. Here are the mixes:
- 1:1 River Sand, Commercial Compost
- 1:1 River Sand, Homemade Compost
- 1:1:1 River Sand, Commercial Compost, Peat (fine grained coir fiber)
- 1:1:1 River Sand, Commercial Compost, Composted Cow Poo
- 1:2 River Sand, Commercial Compost
- 1 Commercial Seedling Mix
- 1:1 Commercial Compost, Peat (fine grained coir fiber)
- 1:1:1 River Sand, Commercial Compost, Dry Horse Poo (uncomposted)
What surprised me the most is that overall they all did ok. I think that goes to show that plants are quite robust and adaptable to their soil conditions. I guess as a plant you would want to be - you never know whose garden you are going to end up in. But when raising seedlings a plant that can be ready for transplant into the garden a few weeks before another is important, so worth while getting the mix right.
|Mix #8 on the right|
Mix #5 - 1 part River Sand, 2 parts Commercial Compost - did really well. Comparing to #1 with only 1 part compost, it would appear more compost is better. Sadly I didn’t think to test a pure compost mix, put I would assume there is a limit. Mix #2 with 1 part homemade compost however also did equally well to #5. Which I am pleased to say, indicates my homemade compost is double the strength of commercial compost. This does concur with what my mum always says “nothing beats homemade”.
|Left mix #1, Right mix #6|
But the winner is...
For overall best performance across the 4 different seedlings the winner is #4 - equal parts of River Sand, Commercial Compost, Composted Cow Poo. Again it is a 2 parts compost to 1 part sand mix, confirming a higher ratio of compost is better. I suspect the commercial compost I bought is made primarily of tree matter thus the inclusion of the manure compost gave it a better balance of nutrients. I now wish I had tested 2 parts homemade compost as I suspect it may have been in the running for first place. My homemade stuff is already balanced with a good selection of organic sources.
Do you have a winning mix?