Online food garden chat July 2020

On Sunday 19 July 2020 the Food Garden Group's third online food garden chat took place. We talked about compost heaps, hay and straw, pruning an espaliered fruit tree, pruning raspberries and blueberries, and how to use seaweed and sea grass. See below for a summary of the discussions.

A busy time in the garden

The discussion started with several people commenting on the fact that they are quite busy in the garden at the moment. Now is also a really good time for creating and changing garden beds, installing irrigation and moving dormant plants and trees.  A few people commented on the importance of make garden beds level, so irrigation and rain water spread evenly in the soil.

The central role of your compost heap

We got talking about compost and that the compost you buy from green waste recycling sites is often not  good quality.  It can contain weeds, for instance Oxalis, if the composting process was not hot enough.  On the other hand, if compost is the result of really high temperatures in the compost heap you can end up with 'black stuff' that does not add much value to your garden. So have a look at compost before you buy it.  Some sources will be good.  Some will be bad. From there we arrived at the central role compost heaps have in our gardens.   Compost heaps ......

• allow you to turn green waste into 'stuff money can't buy' without any costs. For info about making compost read the Making Compost series on the Food Garden Group blog, starting here.
• help moderate the negative effect fertilisers can have on the organisms in your soil if instead of applying them directly to your soil, you apply them to your compost heap
• can be used to filter out herbicides in manure before applying it to your garden. Manure can be a valuable addition to your garden if introduced to  your garden via your compost heap.  For more about this read Marvelous Manure on the Food Garden Group blog.

Hay and straw

From here we got talking about hay and straw, and deep hay mulching (covered on our blog here) 

There is a significant difference between hay and straw.

Straw is what is left after wheat and other grains are harvested. It is a mono-culture, that is, one type of plant, harvested after it has gone to seed.  Nutritional value is low.

Hay, coming from a good farmer who deliberately creates paddocks with a diverse range of grasses and weeds so his livestock has a healthy diet, is harvested before it sets seed (when it is done properly), and therefore has high nutritional value.

Hay is effective as a mulch, but also, as it breaks down, hay adds a lot of nutritional value to your soil.  

Straw is effective as a mulch, but, as it breaks down, will not add much more than carbon to your soil, although is great for the soil microbes.

This why the method is called deep HAY mulching, not deep STRAW mulching.

Sugar cane mulch, another residue of a mono-culture crop, is also an effective mulch, but, is in the same  category as straw.

What to do with my Greengage espalier?

Karen S. came forward with a very interesting question. She showed us a photo of her advanced Greengage espalier (see photo below), now four metres high. The tree does not produce many Greengages, and pruning it every year is now becoming a major effort because it has become so high.  Could it be better to let it grow into a normal tree shape, rather than espalier?  It might produce more fruit then, but there isn't enough room in the garden for a standard-shape greengage in the spot where it is. What would we do?

After a good brain storm we came up with the following recommendation:

• Do not change the shape of the tree into a normal tree shape, but continue it as an espalier.
• Greengage fruit grows on second year wood, so if you prune the tree every year, you remove a lot of wood that would have produced fruit in the coming year, if you had left it on the tree
• Prune half its branches one year (document which ones you have done), then prune the other branches the second year, and then repeat.  This means that all wood gets two years to develop. Branches in their second year will bear the full complement of fruit.
• Remove the top of the tree completely, in other words, both major top-horizontals, just above the point where the horizontals below those, leave the main stem. It will make the height more manageable.  The tree can then devote more energy to the remaining horizontals.
• Prune now, while the tree is dormant, not in spring, when its sap stream will be much stronger.

Later I asked Max K (retired fruit tree professional) for his opinion. He agreed with this advice, and added:

Greengage trees can be hard to control because of their vigorous growth.  After pruning it as indicated above this winter, remove the longest most vigorous laterals (vertical branches) around Christmas time. That will slow the tree down.

Planting and pruning raspberries

Bill mentioned that he recently bought and planted three varieties of raspberries.  It reminded me that there was a recent discussion of our Food Gardeners Tasmania Facebook page about pruning raspberries and that it can be confusing to mix Type 1 (fruit on second year wood) and Type 2 (fruit on first year fruit).  I was going to mention this, but the lively discussion went in a different direction, and then I forgot.  So to capture the gist of the recent Facebook conversation and my thoughts on the subject I updated blog post Making the most of my raspberries.

Pruning blueberries

Someone wanted to know how to prune blueberries.  Whereas most berry varieties need to be pruned every winter, healthy blueberry bushes may not need pruning at all.  Prune away thin spindly branches, if there are any, and branches that may touch the ground next season when heavy with fruit.  More about pruning blue berry bushes can be found in Food Garden Group blog post Pruning Berries.  

Seaweed and seagrass

Seagrass is the fine light stuff.  Seaweed, on the other hand, is kelp, the leathery thick heavy stuff.

Ross reported that, after a lot of phone calls to bureaucrats, he found out that we are allowed to take from Tasmanian beaches above the high-tide mark 100 kg of seagrass or seaweed per person per day without having to ask for a permit.

Some people felt that you need to wash out some of the salt before using sea grass and sea weed in the garden. Apparently Tino Carnevale recommends not washing it, because a bit of salt actually adds valuable trace elements to your soil.

Dirk found that composting sea grass is not easy because it takes a long time to break down.  He recommended that you only use small quantities in the compost heap and spread it out.

Max commented that when he used a layer of sea grass as a mulch on an asparagus bed at the start of the season emerging asparagus stalks broke under the weight of the layer of mulch. He now only uses fine mulches on his asparagus bed, for instance sugar cane mulch.

Ross explained that after collecting sea weed/kelp he spread it out on his lawn, and then went over it with his lawn mower.  That way he was able to shred the sea weed. He then added the shredded sea weed to his compost heap where it readily composted.

Food garden visits in the COVID era

Because there are no community transmission of COVID in Tasmania at present, we can entertain the idea of resumption of face-to-face food garden visits.  We discussed ways to conduct them with minimum risk.  More about this in the August newsletter.

The next online food garden chat

A big thank you to the participants in this online food garden chat!  These sessions offer the opportunity to discuss food garden issues people want advice on. I am finding them to be very useful and interesting. Next month we will have another one.