pottager garden - wk 9

This afternoon it's off to the pottager garden to do some soil analysis tests.

In one of the central beds the spinach and climbing gourds are clearly not doing well, showing signs of powdery mildew and aphid infestation. We know that it's not due to poor air circulation as the site is open and not crowded at all, so it's time to take a look at the soil.

Close up of powdery mildew.

We break off into pairs and each get a bed assigned to us to take a selection of samples from about 10 to 15cm deep. We then mix this soil together in a container to get an averaged sample that we can start a colour iMetric test on. 

Our pH Colour i-Metric Test.

Following the instructions of this particular test we get something that looks similar to the 6.5 to 7pH levels on the colour chart. Although Margaret and I both feel it is quite hard to tell as the soil colour looks mostly grey rather than green! Anyway Pav is in charge of recording the results for each of the beds and once completed we head back inside the pod.

Looks a bit tricky to pinpoint the exact colour!

Here we are going to perform a pH meter test using a plastic meter with a sensor in the base of it. Marcus explains how this particular test will work in water. The idea being to measure an certain weight of soil on the scales and then add it to a certain ml measurement of distilled or rain water - and stir.

Afterwards you add the meter test and wait a while for the number to stabilise. Our number comes out at 7.4pH ! Which is very high and on the alkaline end of the scale.

The meter test is easy and more accurate.

Marcus explains that the meter test is more accurate and that he usually adds an extra point to the colour iMetric test to allow for it's inaccuracy.  

Across the whole garden we get similar high readings of approx 7.1- 7.5 pH and surmise the pottager is on the whole a bit wet and smelly and anaerobic and not the best. The plan of action is to:

• Stop/reduce the automatic watering.
• Raise the beds to increase drainage and aerobic activity.
• Addition of some sandy loam and compost to add mineral matter.
• Fork (not turn) the beds to improve aeration and aerobic activity in the soil.
• Apply a potassium sulfate solution to increase acidity.

The pottager plan with the pH test results.

With the case of the powdery mildew spinach - Marcus suggests instead of ripping out all the plants and sewing new ones, that it would be much better if we trim off the worst effected leaves (compost these of course).......

Trimming off the worst affected leaves.

.....then apply a sulphate powder to the trimmed plants and surrounding soil as this is a very good and easy treatment for powdery mildew. Of course fixing the soil is the number one task to improve plant health over the long term.

The next week before the Tread Lightly Festival we set about doing some soil improvements in the pottager garden. The sandy loam is added. This helps to improve the soil and also works to raise the beds up for improved drainage. We make sure to rake everything immaculately to impress the public (and Marcus) and set about sewing some peas and kale into the freshly raked beds.

The loam is added and raked over before planting some kale and peas.

Everything looks so much better and it's only been a little bit of work to make a large improvement. Later on we will revisit the pottager to see how the soil condition and plants are improving and how well the hot heap is breaking down.