Re-using Old Tyres

A great use of old tyres. Sitting on them should be all right but would you grow veggies in them?

It wasn’t too long ago most car tyres ended up on bonfires in autumn.  Now though there are tighter controls and a bit more understanding about just how polluting they can be.  Finding new and interesting things to do with them can be entertaining and more and more people are being really inventive when it comes to reusing them.  There are lots of play parks around that have soft surfaces made from the ground up rubber after the steel wire has been taken out and we probably sit on them as the new park benches have old tyres mixed in with old plastic carried bags.

Other uses are:

·         Roof tiles

·         Road surfaces (the quiet type)

·         Children’s swings (cut to look like swans)

·         Earth ship houses with rammed earth inside them as walls.

·         Growing flowers

·         Keeping down the silage sheets

·         Rolling down hills

·         Making sandals and furniture

The biggest discussion though is whether it’s a good idea to use them for growing vegetables.  The dark colour absorbs heat, the drainage is good and they are ideal to stack up for when you want to grow spuds, strawberries or tomatoes. They can also be used effectively on steep banks to stop soil erosion.

Under the EU Landfill Directive introduced a few years ago, tyres have been classified as hazardous waste, with a ban on whole tyres being sent to landfill.  So do tyres leach out toxins which are taken up by the plant to end up on our plates or is it just bureaucracy gone mad?

A few tyre-ing facts

Tyres are extremely durable. During manufacture, natural rubber is combined with synthetic rubber and treated with a cocktail of chemicals, some toxic or known carcinogens, others more innocuous, to make the tyre withstand all the forces that will act upon it on the road. 

The forces that tyres have to resist on the road are: sunlight, water, acidity, abrasion and friction with the road surface. Each of these forces works in a different way on the tyre, but over time all break it back down into its constituent parts.

During this process, the various chemicals and compounds are slowly released through ‘off-gassing’, particulate matter or 'tyre dust', or as chemicals, leaching out into water. Every tyre loses about 20% of its weight during its lifetime on the road, getting slowly ground down and blowing away in the wind.

Tyres and toxins

Most off-gassing occurs within the first year, for example, that 'new carpet smell', and given that tyres typically are 3 to 5 years old before being discarded, this would not really seem to be an issue.

What should be of greater concern to vegetable growers, is the gradual erosion through water and sunlight, and any leeching of chemicals and toxins that may occur to contaminate the surrounding soil, water and anything grown in it.

What happens when tyres degrade

The disintegration of tyres is well demonstrated when they are used to weigh down covering sheets in silage areas. The tyres usually degrade to point where the steel belt starts coming out of the tyres after ten years.

Yet the effects aren't completely understood. A report by the Environment Agency states that "little is known about the long-term leaching of organic chemicals from tyres in landfill sites.”

Like many types of rubbish we produce today, we don't really know what the individual effects of the leaching chemicals are. However, there are strict controls in place for the proper disposal and handling of used tyres, and it is illegal to dump them, with large fines for fly–tipping - showing that problems with tyre disposal are appreciated.

Risky Business?

Mischa Hewitt is the author of Earthships in Europe and runs Self Building an Earthship training courses in Brighton found a long list of toxic chemicals in the tyres and wonders if it’s worth growing edibles in them. “When it comes to growing food in tyres, why take the risk? Whilst the quantity of toxic chemicals maybe small, we don't know the exact amount used in tyres because of commercial secrecy.

People generally grow food organically for themselves to avoid exposure to synthetic chemicals. It seems ironic that a 'Permaculture way' of reusing tyres could be unintentionally reintroducing potentially harmful chemicals back into the equation.” 

Even lining the tyres with polythene before the soil is put in doesn’t seem to attractive now.

Tunnel or Not

Is it possible to make a polytunnel from our old trampoline?

Tunnel Vision

I’ve turned into an embarrassment again with the young ‘uns.  My mobile phone is apparently really outdated; the last time I was this out of touch was when my phone had a three inch aerial sticking out of the top and was shaped like a brick.

Now I am faced with getting a smart phone, something that can take up more time in my day.  I have a limited vocabulary when it comes to texting on a numeric keypad on my old phone and usually just end up saying “OK” as a reply to almost everything as I can’t be bothered to press the little digits more than a few times before I get bored.  The new smart phones would do away with all of that as they have proper keypads so I could write “That’s OK instead”, before falling into a bored stupor.  

I have to weigh the facts though.  Do I NEED new phone?  Or do I WANT a new phone?  I started looking at the cheapest contract ones and they work out cheaper than the pay tariff as you go I am on now.  Alas though, these phones are out of date (by tekky standards) and the newer-faster-smarter phones are twice the cost, but they have all sorts of gizmos to play with.  I am really confused about it, mainly because I would happily live without a phone if I could.  

I have other dilemmas when it comes to buying and getting value for money too.  I have cleared a spot in the garden (got rid of the trampoline) and have enough room for a polythene tunnel.  It wouldn’t be a big one by any standards, I have an area of 12 feet by 20 feet to fill (4mx6m) but there are so many different types that I am as confused about tunnels as I am by phones. I initially spent a happy hour trying to make a polytunnel frame from the trampoline poles... I’m sure that I could do it but my lads insist they will be using it again in the summer.

Comparisons

My last tunnel was 30 feet long and heavy duty so could withstand the strongest winds coming off the Swilly.  I could get a smaller version of that, which would cost me about 600 euro which seems a bit steep.  The area where the tunnel is going is in a really sheltered space too surrounded by (but not in the shade of) trees, hedges and a wall, so I was thinking of something a bit more lightweight.  I pondered over a greenhouse but a new glass type that size would cost over 1000 euro and if you buy one second hand it’s usually “buyer to dismantle and collect” Now I don’t know if you have ever dismantled a greenhouse but generally you are left with a pile of aluminium strips that you don’t have a clue how to put back together again and a few bags of broken panes of glass... So I have discounted that line of buying. 

 Choices

There are other cheaper types of polytunnels on the market and an ever growing amount of companies bending galvanised tubing into hoops.  The coverings seem different too and range from thick clear plastic to hazy plastic and covers which sandwich green mesh in between layers which is supposed to give both strength and shade. They all have 5 year or more guarantees so chances are any will do the job effectively.  The design I am looking for in the hoops if for them to have straight sides.  The tunnel will be small enough without me being unable to get into the edges with benches or vegetable beds, so every inch of space is needed.  This thankfully cuts down the choices of companies as not all of them produce this type of design.

Cheaper models don’t seem to have wooden door frames either and rely on zip flaps similar to a tent, which will let you push a wheelbarrow through but I am wondering if it’s heavy duty enough.

It’s going to take me a bit of time to come up with the ideal tunnel for my needs; I will have to weigh up all of the options before buying. I’ll have to be realistic about the price too, I know it will cost me a few hundred euro to get a good one but it will be worth the extra money. I have to take into consideration any extras such as black plastic for the flooring or the cost of putting in raised beds... and buying plants and seeds for that matter.  It all adds up.  

If anyone has an old tunnel lying unwanted...give me a shout!

Seeds

Let’s see if last year’s broccoli seeds are viable.

I was reading a story this week about a man that single handedly planted a forest covering 1,360-acres.  A little more than 30 years ago, a teenager named Jadav "Molai" Payeng began burying seeds along a barren sandbar near his birthplace in northern India's Assam region to grow a refuge for wildlife. Seeds are magical things and this time of year it always amazes me just what gardeners can get out of just a few packets of these living micro organisms held in a state of suspended animation or dormancy. 

I have mixed success with seeds, that’s probably the same in nature and why some plants produce so many of them.  There are many things that can affect the viability of seeds, including moisture, air, temperature, and light. In an ideal situation and environment, every single seed we planted would grow into a seedling, but as we all know, that doesn’t normally happen. 

Although dormant, seeds are still slowly using their food reserves. Some have more in reserve than others and can lay dormant for years before bursting into life when the right weather conditions appear.  Small flower and vegetable seeds do deteriorate over the year and that’s why tend to go out and buy a new packet of broccoli seed every year instead of using the seeds from last year’s unopened packet.

When the right weather conditions wake the seeds up they begin to germinate and emerge from their hard seed coat. Here is a brief explanation of how a seed wakes up and busts into life, just like us gardeners do when the weather warms up.

There are four major factors that are affect germination:

Moisture:  A dormant seed only contains 10-15% of water and is essentially dehydrated. The seed has to absorb water in order to become active. It is taken in by the seed coat and enzymes in the seed become active and they start using stored food reserves. The embryo then begins to swell and the softened seed coat ruptures as the seed grows too big for its encasement and germination has starts. The seed leaves or cotyledons now show but photosynthesis doesn’t begin until the true leaves are developed and at this point in development the seedling is still surviving on its own food reserves.

Air:  In the dormant condition the seeds respiratory rate is very low and so oxygen is required in very small quantities. But for germination, oxygen is needed in large quantities. The seeds get oxygen that is dissolved in water and from the air contained in the soil. If soil conditions are too wet, an anaerobic condition persists, meaning that the seeds are living without air so will hold back germinating until they feel the supply of air will be constant.  Aren’t they clever?

Temperature:  Germination can take place over a wide range of temperature and is specific to individual crop types, and can be specific to varieties. When I was growing seedlings in my polythene tunnel I had a hotbed with heated cables. The cables were put at different depths under sand to regulate how much heat each type of seedlings got, I did make life a bit complicated for myself though as there is an optimum temperature for plants.  The optimum for most crops is between 65-75°F and most seeds will germinate happily in this range.  Exceptions do apply though, for example lettuce germinates best at 65°F and can be held back at temperatures over 68°F while peppers and aubergines  prefer warmer temperatures around 80°F and will not germinate well at cooler temperatures.  If your soil is too cold or too hot, your seeds may not sprout. Check your seed packet to find the best temperature needed for your seeds.

Light:  Light has varied effects on germinating seeds of different plants. Some seeds need light for germination, while in some seeds germination is hindered by light. Most wild species of flowers and herbs prefer darkness for germination and should be planted deep in the soil while most modern vegetable crops prefer light or are not affected by it, and are planted shallowly to allow small amounts of light to filter through the soil.

How deep to plant?

Seed size usually is a good indication of how deep to plant your seeds, which usually corresponds to how much light they need. The general rule of thumb is to plant your seed at least as deep as the seed is long. Certain seeds need light to germinate and shouldn’t even be covered with any soil! Check the back of the seed pack for specific information on how deep to plant your seeds.

Why didn’t my seeds germinate?

Have all the seeds failed? If this is the case, more than likely it is an environmental condition. Seeding too deeply, planting in cold soil, too much or too little water, improper soil preparation, and birds or rodents are the most common causes for environmental conditions that prevent seeds from germinating. When germination is poor it is most likely a degradation of seed quality, and the seed has begun to die. In general seeds hold high germination rates for 2-3 years but if the packets have been opened the seed needs to be kept in airtight containers and not left in a damp shed like my broccoli seeds have. I won’t be risking them this year