The plants’ own fertilizer
Soon stinging nettles/poison ivy will poke out. Stinging nettles are fantastic fertilizer for tomatoes in the greenhouse, so maybe this is the year to try making your own fertilizer.
Scandinavian studies show that stinging nettle fertilizer is especially filled with nitrogen, which is something all plants need and all your plants in the greenhouse can benefit from. This is something all organic farmers have learned but now is established.
They sting but are great as fertilizer.
Photo: Grøn Kommunikation
You put on rubber gloves, so you won’t get stung. You pick all the stinging nettles you can find and when you’ve collected one kilo, you put them in a plastic barrel or a tub. It doesn’t matter that they dry out if you can’t collect them all at once.
Now pure 10 litres of water in the barrel for every kilo stinging nettles. Put the barrel in the sun and cover it with a sack, to temperate the water. Stir it every day to aerate the water. When the stinky water is dark brown and doesn’t froth, the nettle juice is ready.
Dilute with 10 litres of water for every litre of nettle juice. You can also use the mixture against aphids on your roses or other plants in your garden.
Om 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.