How plants grow

Oct 15, 2012by Farmer Liz

Background

My first two posts were about minerals in the soil and how plants use them, and about microbes (and larger creatures) in the soil and how they help to make minerals available to plants. This post is about understanding how plants grow so that we can help them by applying minerals and encouraging microbes at times and in ways that will be most effective and efficient for us and for the plants.

Stages of plant growth

This is a huge topic and far too much for me to get into in one blog post, and I’m no expert anyway. The main concepts that you need to understand are:

· Seeds – what triggers them to start growing? What conditions will be the best start for a healthy plant?
· Roots – how do they transport nutrients to the plant? What are exudates?
· Leaves – what is photosynthesis and what does the plant need to maximise production?
· Flowering and fruiting – what triggers flowering and fruiting? How can it be optimised?

I have found the book “How does your garden grow?”, by Chris Beardshaw, very helpful as it covers everything you need to know about plants and soil with some great diagrams. It does get into biological details in some sections, but mostly keeps things simple and easy to understand. I’m sure there are other references out there, so please let me know if you have a favourite. I have had a look for an online reference and I can’t find anything useful at the moment, again, if you know of anything, please let me know.

Monitoring plant growth

Plant sap refractometry is a measure of the sugar content of sap. This is a very cheap way to measure the health of a plant. If the brix content is greater than 12, then the plant is healthy.

Plant sap pH is also an indication of plant health, with 6.4 being the ideal pH. Higher or lower than 6.4 indicates a mineral deficiency, and will cause the plant to be vulnerable to pest and disease pressure. This can be measured using a sap pH meter.

Maximising plant yield

I have summarised the main methods for applying minerals and microbes in a table, download from google docs here.