We've seen gravel mulch, glass mulch, rubber mulch - darn it, we've even seen coloured mulch. But just when you thought we'd seen it all, along comes a Kiwi vigneron who wants to try his hand at mulching with mussel shells. Mussel shells?

It makes sense, really! In New Zealand they're hardly short on a steady supply of these little molluscs yet they're only valued for their meat. The shells end up as a wastage product.

So is this just a case of reusing a material in another format? Not at all. Apparently the Renwick vineyard is trialling the side benefit of ripening their grapes through the increased light mirrored into the vine's canopy as the shells fade. It increases the ripening characteristics of the fruit without increasing the levels of sugar.

How could Mussel shell mulch be useful for home gardeners?

It doesn't necessarily need to be mussel shells, it could be any type of shell that is used (Abalone may be a little too hard, and not easy to source either).

If this vigneron's trials are successful it could mean a boon for cold climate gardeners who struggle to grow fruit trees because the produce won't ripen in time. New Zealand's a good climate to be testing this in and if it proves true the reflective qualities of this mulch will become highly prized.

If you plan to try this mulch in your own home garden you may want to wash them a few times before applying to your fruit trees. The salt that can become encrusted on these shells will eventually break down and will increase the alkalinity of the soil - hardly a bonus for lime-loving fruit trees.

Due to the interlocking shape of these mussel shells they do work well as a mulch. They will restrict the growth of weeds and retain moisture in the soil.

Is there anyone else who's been using shells as mulch in their gardens and found similar benefits?

Posted by Stuart | Permalink | Comments (4)

Many home gardeners opt to buy in mulch when the weather begins to warm. In an effort to protect their garden beds from water evaporation and help combat weed growth they instinctively purchase large mulch loads and then spend the weekend dispersing it.

But, have you ever considered what goes into making that load of mulch?

Presumably it's bark and leaf matter that's been recycled as a byproduct of the timber millers. And, in many cases this is what you're getting. However, if you expect it to be 100% of the overall product you're either living in denial or ignorance is bliss.

Many mulch wholesalers and manufacturers will substitute a variety of items to bulk up their volumes. Wood pallets and crates - usually made from foreign timbers are a great alternative to sourcing natural timber fibres. And, while we would like to believe that it is just the waste products that are being used, many times the whole tree including the inner core is ground.

While this is still all natural it means that you're the one getting the raw end of the stick. The inner trunk of the tree will decompose far quicker that the bark which means you will have to mulch your garden more often. Suppliers who mulch the whole tree and imported softwoods benefit from cheaper overhead costs and also from increased customer orders but usually charge similar prices to quality providers.

And, what about those articles that warn us of bringing ants and termites onto our properties. Is there any cause for concern? The simple answer is no.

How can you tell what's in the mulch?

Before you allow the mulch to be offloaded onto your driveway, check the contents. Here are some things you should be able to look for and discuss with the supplier;

• Check for green or light-coloured wood - bark mulch should be fairly dry to moist if it is old enough and should have a dusty feel about it. Softwood that has been sitting in a mulch pile for some time will look greenish and have a slimy texture.


• Ask the supplier where they source their mulch from - many tree removal companies run a mulching arm as part of the business operations. While this is not a bad thing and the mulch produced will have no ill-effects on your gardens, it is an inferior product compared to milled bark and should be much cheaper.


• Ask how long it is stored for - the longer the mulch is stored the more decomposing has already taken place. If the mulch has been sitting in their yard for some time then it may rot down too quick in your garden beds, and thereby force you to buy more later in the season.

The best mulch you can get is from recycling your own plants and materials, and it's cheaper too. But if you must buy from a mulch supplier, take the time to find out what you're getting and don't just settle for what you've been given.

Posted by Stuart | Permalink | Comments (4)

In Helotes, San Antonio Texas (a mere drive southwest of Austin) is a fire that has been burning since almost Christmas and continues to burn. The cause of this month-long fire - a mulch pile!

Measuring 80 ft high (24m) and 800 ft wide (240m) - the size of five Olympic swimming pools - this mulch monstrosity has been pouring out smoke since Dec 26. Residents have been displaced from their homes and billeted at local accommodation outlets throughout the city.

Even after a specialised firefighting team were brought in to extinguish the fire - costing more than $1.7m - it appears that the fire won't be brought under control for at least another month. That's one very hot mulch pile.

It's tragic that this problem even occurred but it highlights how hot organic matter can become once bacteria begin to do their work. Gardeners are always talking about how hot the centre of the pile needs to be in order to kill any wayward seeds but this story borders on ridiculousness.

Link

Posted by Stuart | Permalink | Comments (3)

Every year more than 700 million new tyres are created replacing a similar amount that ends up getting burnt or discarded in waste sites. In fact, in Australia alone more than 70% are still being tossed away annually.

Fortunately gardeners aren't wasteful people and we've used them to stack potatoes, add a swing for the kids and even turned them inside out and planted flowers in them. But there are only so many potato tires, swings and planters that one garden needs.

So the new trend is to apply rubber mulch on your garden beds and why not? It comes in a range of colours, doesn't break down (not in your lifetime anyway) so you shouldn't need to replace it and it's easy to apply. Plus there are no smells that keep your neighbours indoors.

With so many benefits it seems hard to bypass an obvious solution to the rubber recycling problem.

That is until you find out whether it has any detrimental side effects to your garden. And, alas, it does. Recycled rubber mulch contains enough zinc, cadmium and other heavy metals to destroy your favourite ornamentals in one foul swoop.

Rubber mulch is often extolled with the virtue of containing nitrogen but it is so minimal that the heavy metals far outweigh any pre-conceived benefit.

This would be okay if it were where the story ended. You could easily decide to steer clear of applying rubber mulch to your garden and resume normal organic applications. But it seems that recycled rubber mulch is becoming more common as a bulk filler for normal organic mulch as well.

This is a little disconcerting for gardeners especially when you can't identify many of the ingredients that go into the mulch you buy from your soils provider.

The solution: It pays to ask. If your mulch retailer can't tell you if recycled rubber is used as a filler then find one that can. At the very least, if you are still in doubt, go back to composting your own natural waste products.

Posted by Stuart | Permalink | Comments (0)

Of the estimated 36 million Christmas trees expected to be bought this year in the US 93% will be recycled into garden and landscaping mulch. While this is a worthy back-slapping statistic it needs to be considered that 7% still won't be.

Considered as a ratio, 1 in almost every 10 trees will find their way into landfill, disposed of unthoughtfully or worse still - incinerated. Which must make us wonder why we even bother to educate people to use 'real' Christmas trees instead of their artificial counterfeits.

Sure, a 'real' Christmas tree will break down within 5 to 10 years while a plastic wanna-be will take aeons but the environmental effect of disposing rather than recycling is of paramount importance.

Assuming the average Christmas tree weighs 4.5kg this calculates as 11.5 thousand tonnes of rotting plant material in places where the nutrient run-off may be detrimental rather than helpful.

Scarier than this is the thought of having 11.5 thousand tonnes of pine incinerated causing creosote deposits and harmful smoke polluting the environment.

What's the Answer?

People are truly lazy beings. If something becomes an inconvenience then as a species we will find the easiest way to deal with it. So, when it applies to waste we would rather dispose of it than drive out of our way to have it recycled.

Therefore, each retailer of 'real' Christmas trees should become responsible for the recycling and mulching of them. If this means raising the price so that the trees can be collected and recycled accordingly then so be it.

Let's be a little less consumeristic at Christmas and make sure that 100% of 'real' Christmas trees are recycled into garden mulch.

Posted by Stuart | Permalink | Comments (2)