Monday to Wednesday this week was dedicated to learning about composting. Who knew there was so much involved in making good compost! The basic elements are carbon to nitrogen ratio, water and oxygen. The balance needs to be right to get the compost decomposing. You can tell it has started working when the compost pile heats up. The bacteria, microbes and insects have got to work! It can get as hot as 70° Celsius, usually it will get to around 50º C and then start to cool down. This is when you can turn the compost, supplying more oxygen to get it going again. The high temperatures help kill off weed seeds and any diseases from plants that have been included in the batch.
Compost can be made out of just about any organic material. It will all breakdown eventually. Then end result is called humus (pronounced ‘Hugh-miss’ not hummus the chickpea dip). Humus is dark brown, nearly black, and has a light earthy smell. The right balance of carbon to nitrogen will mean the compost is completed a lot faster. High carbon items are called ‘browns’ and high nitrogen ‘greens’. Ideally you would mix them so the ratio of carbon to nitrogen is 30:1. When it is finished composting the remaining humus has a ratio of 10:1. This is now very stable and will not breakdown further.
To test if the compost is ready to use you can seal a small amount in a plastic bag overnight. It shouldn’t puff up the bag or give off any odors. To test the quality of the humus you can use it as potting mix for something like radishes. If they sprout successfully, great! If not, something is a bit off. Maybe there are too many salts leading to reverse osmosis or pesticide contamination.
We went out to Felton Road Winery in Bannockburn to see how they create and use compost on their vineyard. They have a bio-dynamic philosophy to making wines based on the ideas of Rudolph Steiner from the 1920s. It’s not based on hard science (no real research done) but works for them and as Gareth said, at least it’s not doing any harm. They do make delicious wine, so maybe there is something to it.
They make their compost out of the pruned vine canes and other crops they have harvested onsite. They believe using plants grown onsite means the compost won’t change the terroir (environmental factors of a specific piece of land) that is expressed in the wine. They make several compost piles around the property. This means it is easier to access and spread where needed.
Thursday was my first day in the nursery for propagation. We started with an induction, health and safety and a tour of the facilities.
A nice warm place to spend a cold winter’s day.
I planted some geranium seeds in a hygiene tray using a 50/50 mix of potting mix and sand. You fill the tray with the seed raising mix, then level with a float. Sprinkle the seeds on top. Hopefully spread out evenly. The geranium seeds were a bright gold colour that made it really easy to see where they were even though they are so small. Then cover them with vermiculite and store in the greenhouse. There they will be watered by the mist sprinklers and then covered with a glass screen to help heat them up and not get too wet to start with.
I can’t wait to check next week to see what has sprouted! When they are bigger they will be individually potted and eventually sold at the school’s annual plant sale in October.
Weather – Snow was forecast all week but never arrived. Mornings were frosty. It rained heavily on Wednesday night through to Thursday morning.