Online food garden chat August 2020

On Sunday 16 August 2020 the Food Garden Group's last online food garden chat for the 2020 winter season took place. We talked about snow peas and peas, beans, biochar, green manure, Oxalis, citrus fruit, Chilean Guava and the layering propagation method. Below is a summary of the discussions.

Peas flowering but not producing any pods

Max reported that climbing peas he sowed in April look healthy and green and have been flowering since mid July, but that there is no sign of any pods forming.  

Susan discussed this with people at the University who do a lot of work with peas, and was told that this is because fruit setting is aborted when it is too cold.  Peas are self-pollinators, and that means an absence of bees and other insects (because of the cold) is not a problem, but there is no successful self-pollination when temperatures are too low.  The pea plants will continue to produce flowers and will produce peas later in the season when temperatures are up, so this does not mean there will be no crop.

Mel commented that her snow peas have been producing pods for some time.  The name snow pea perhaps indicates that this type of pea is productive at much lower temperatures than normal peas. If you want peas in the middle of winter, sow snow peas.  

Max had sown his peas in April as a green manure.  They were old seeds and he was surprised when they turned out to be still viable.  He then decided not to dig them in and see what the result would be.  There is clearly no advantage in sowing normal peas really early.  He normally sows his peas in late June.

Beans are also self-pollinators. This means you can have two bean varieties with a few metres between the varieties, and not have any cross-pollination.

Using charcoal from your wood heater

Max mentioned that he makes biochar and wanted to know whether anyone had an easy way to 'pulverise' the pieces of charcoal he saves for biochar from his wood heater.  He puts it in a large bucket and then bashes it with a mallet and finds that hard work. 

Ross commented that he uses his shredder and that this shreds the char coal pieces into small bits with little effort. Steven commented that he breaks hit charcoal up a bit by hand, but otherwise does very little to it because it does not actually needs to be small bits to be effective in soil.

The crushed charcoal is covered with diluted seaweed extract or some other nutritious fluid that plants like. It can stay immersed for between 15 minutes to 24 hours.  The charcoal, then officially known as biochar, is then separated from the liquid, and can then be added to soil in small quantities immediately, or stored away and used over a period of time.

We talked about the benefits of biochar. Karen commented that she used a commercially produced biochar and that her vegetables produced all leaf but no crop.  Others thought that this might have been because an already nutrient-rich soil was made even richer in nutrients and that, in response, plants formed leaves in great quantities instead of focusing on flowers.  Biochar, like other additives such as coffee grinds, are to be used a little from time to time, rather than a lot all in one go.

Biochar stimulates soil organisms and they in turn create conditions in which plants can access nutrients more readily.

When green manure is 'ready'

Ross explained how he did not want to dig in his green manure when it was ready.  Instead he covered it with black plastic when it was time to end it.  He had expected the plant material underneath to break down, but that the plants continued to grow.

Max commented that he uses a pair of scissors to cut green manure to bits, and then gently works it into the soil with a spade.  This method is explained in the Green Manure section of blog post https://foodgardengroup.blogspot.com/2020/08/vegie-patch-basics-4.html .

Karen commented that she chops it up with a spade and then 'stomps all over it' to work it in.

Max commented that black plastic has its uses.  Last year he covered an area that had a lot of Oxalis with black plastic for half a year, and to his surprise, that was the end of most of the Oxalis. Mel commented that she was using black plastic to kill twitch in her garden, brought in with new soil.  However, black plastic, if soil is covered for a long period of time (no water, increased soil temperatures), is deadly to soil organisms, so generally speaking it is better not to use it.

Chilean Guava

Gaye wanted to know what we can do to make our Chilean Guava grow more vigorously.  The bushes we have are now around five years old, grow very slowly, and produce some tiny, tough berries, but not many. Last year during a food garden visit to Valerie's garden garden at Howden we saw a Chilean Guava that was a proper big bush with lots of berries.

Someone commented that the sale of Chilean Guava in nurseries was banned last year when they were affected by a rust that they are trying to keep out of Tasmania.

Would Valerie's Chilean Guava be so successful because it is a fast growing variety, or is it in very good soil?

With the help of Complete Organic Fertiliser our bushes are growing better now, but at this rate it will take a decade before they look like Valerie's.

No one had an answer to the question.  We hope that Valerie will tell us her secret!

My citrus tree has yellow leaves

We discussed causes and agreed that feeding it Epsom Salts might solve the problem because in many cases yellow leaves are caused by a lack of magnesium. Ross foliar feeds his citrus trees with a watering can full of water and 3 teaspoons of Epsom Salts.

Blog post Fruit - Citrus in Tasmania on the Food Garden Group blog says about this:

Citrus trees perform best when a wide variety of trace elements are available in the soil. Spraying leaves regularly with seaweed extract is really good. If every three months or so you mix a tablespoon of Epsom Salts (magnesium sulphate) plus a tablespoon of iron chelate (iron) in a watering can full of water, and spread this evenly around the drip line, your Citrus tree will be really grateful. Yellow leaves with green veins is often caused by a lack of iron.

Max commented that epsom salts bought at the chemist (for foot baths) are much cheaper than buying the same stuff from nurseries.

We then talked about what people use lemons and other citrus fruit for.

There is a great recipe for cumquat ginger marmalade on our FGG Extra blog.

Karen offered to give us her recipe for Maroccan cumquat desert.

Ross offered to give us the recipe for a spray-on lemon wipe that he and Elizabeth use in their kitchen!

You may see these recipes on our FGG Extra blog in coming months!

Propagating a thornless blackberry

How is it best done? A great question. Two of us thought 'layering'. 

Karen explained that there is 'normal' layering and 'aerial layering'.

• In normal layering you take a low branch, bend it down to the ground, and then cover a small section of the branch with soil. Use a few tent pegs or something similar to keep the section in the soil. Make sure the soil remains moist. Over time roots will form. In a few months time carefully cut the branch so it is no longer connected to the parent plant. You have a new plant with exactly the same genetics as the parent plant.
• Aerial layering is used when there is no branch close to the ground to do the layering with. Put a small amount of moist sphagnum moss around a short section of branch. Completely cover it with plastic, so the sphagnum moss does not dry out. Roots will form over the next few months. Then seperate the branch from the parent plant.

And that was the end of the last winter-2020 online food garden chat

We didn't get huge crowds taking part in these sessions, but that allowed everyone who took part to have a say and discuss whatever food garden issue was relevant to them.  Our collective food garden knowledge resulted in helpful answers in most cases.

Many thanks to my co-conspirators in this project, Susan F. and Ross T, and to everyone who took part! Your contributions made this a success!

We might resume online food garden chats if COVID-19 forces us to stop face-to-face food garden meetings during the 2020 - 2021 season, and there might be a new series of online food garden chats during winter-2021!