A DIY Guide for the home-gardener Dave Allen 2002
Make A Hyper-Tufa Garden PlanterTable of ContentsWHAT IS TUFA? 1WHAT IS HYPER-TUFA? 1BEFORE YOU BEGIN 2WHAT YOU WILL NEED 3MAKING A PLANTER MOULD 4MAKING A RETARD MIXTURE 5THE HYPER–TUFA RECIPE 6MAKING THE HYPER-TUFA MIXTURE 7MAKING A HYPER-TUFA PLANTER 8FINISHING YOUR HYPER-TUFA PLANTER 10AGING YOUR HYPER-TUFA PLANTER 11GLOSSARY OF TERMS 12 i
Make A Hyper-Tufa Garden Planter 1What is tufa?Tufa exists in nature. It is a typeof rock. It builds up over time as adeposit from water carryingchemicals in solution such ascalcium carbonate or silica.You can see tufa deposited:• in limestone caves as stalactites and stalagmites• around hot or cold water mineral springs• as concretions around volcanic blowholes or geysersNatural tufa was once carved and made into ornaments for gardens. But,today most natural sites are protected and tufa cannot be extracted. What is hyper-tufa? Hyper-tufa is a homemade replica of real tufa. It is just as good for garden ornaments and does not require destruction of the environment to produce. Hyper-tufa is made from Portland cement. Cement is used to make ordinary concrete and it comes ready bagged from the hardware store. Sometimes, real tufa contains lots of foreign and organic matter: bits of harder rock and stones, twigs, branches, leaves, and even insects. These ‘additives’ can also be mixed in with the cement to make authentic looking tufa replica.
Make A Hyper-Tufa Garden Planter 2Before you begin Making hyper-tufa is similar to making concrete. To be successful at making hyper-tufa garden features you first need to learn some things about concrete. Here are some important points you should know about concrete. • To make concrete, cement, aggregate and water are mixed in specified amounts to produce ‘wet’ concrete. • ‘Wet’ concrete is a liquid. It can be poured to fill spaces or shapes. • Concrete ‘sets’ (goes hard) over time, not by drying out, but because crystals grow within the concrete. • As the crystals grow, they interlock to make the concrete strong and go hard. • The speed at which this setting process occurs depends on the temperature. When it is warm, the setting process is fast. If it is cold, particularly if it is frosty, the concrete may not set at all. • Once the concrete starts to set it will continue to harden for a month or more, providing it is kept moist. • Hard aggregate materials (stones, rock chips, etc) added to concrete will STRENGTHEN the mass. • Soft aggregate materials (wood, bark, peat, etc) added to concrete will WEAKEN the mass. • The finer the aggregate particles then the more cement is needed. This is so that each particle is covered with cement. WARNING CEMENT IS CAUSTIC This is not only hard on your hands, but could cause serious injury to your eyes, or lungs if you breathe it in. Consider wearing safety glasses, a mask over your mouth and nose, and rubber gloves. Another consideration is your garden pond, plants, and the fish. Use caution around a pond, so that bits or chuncks of cement do not fall in.
Make A Hyper-Tufa Garden Planter 3What you will need Now that you know something about concrete, you are almost ready to make your first hyper-tufa planter. First, you are going to need some tools to do the job. Here is a checklist of the things you will need:! A pair of gloves (thick rubber ! A wire brush or very stiff is best.) scrubbing brush.! Large shovel for heavy ! Some bags of cement. (Just mixing of ingredients. buy 1 or 2 to begin with.)! Smaller shovel, for example ! Some aggregate. This is a coal shovel, for putting the the “hard stuff” to give mix into the mould. strength to the mix. It could! A wheelbarrow in which to be regular “builders mix” mix the ingredients. which is a mixture of sand and shingle; available in bulk! A short stick about 450 mm from most hardware or long for tamping the mix. buildings supply yards.! Some plastic sheet (black ! Some peat This is the “soft garden polythene). stuff” to give the mixture! A selection of “moulds” of the some texture. It can be shape you want to make a bought as bags of coarse hyper-tufa pot or feature peat at a garden centre or it (cardboard boxes of various can be any organic material shapes, plastic pots, plastic from the table below. rubbish bags, buckets, old lampshades, or anything that takes your fancy!).Some alternatives you could use for:AGGREGATE PEATAny combination of: Any of the following, either alone or• river gravels in combinations:• road chips of various sizes • granulated pine bark (fine)• fancy coloured pebbles • chopped straw, broken twigs• lime chips • coarse untreated wood shavings• pumice • chopped flax flower stems and• scoria chopped flax fronds • spaghnum mossYou may want to start simply, then • chopped fern trunks andexperiment with different materials to shredded frondsmake your own distinctive aggregate. • bits of coal or coke, charcoal • pine needles • chopped bamboo, coconut fibre
Make A Hyper-Tufa Garden Planter 4Making a planter mould Before you start making the hyper-tufa mixture, you first need to make a mould of the shape and size you would like for your planter. You can use almost any container that will form a mould: plastic bags, cardboard boxes, buckets, etc. As you gain experience with making planters you can experiment with different containers to find ones of a shape or size you like the best. A good, simple way to begin is with ready-made cardboard boxes. For your first planter find two boxes; one large one and another slightly smaller so that it will fit inside the larger one with at least 50 mm clearance all around. An ideal large outside box is the “banana-box.” This is the strong cardboard box in which bananas are shipped. They are generally available from supermarkets or fruit shops. These boxes make an ideal sized planter that is about as large as one person can lift with difficulty when finished. For the smaller inside box you will need to find one that gives the required 50 mm or more clearance all round when placed inside the banana box.
Make A Hyper-Tufa Garden Planter 5Making a retard mixture Once you have made your planter and the mixture has set, you will remove the boxing. You then have to scour the surface to expose the various ingredients and show the texture to its fullest advantage. Now this can be a difficult job. If you strip the boxing off too soon the whole lot collapses, or at the very least cracks appear. Or else, you leave the boxing on too long and by the time you come to strip it off, the planter is so hard you will find scouring the surface very difficult. What is needed is something that you can paint onto the surfaces of your boxing, to delay the setting of the hyper-tufa mix at the surface of your planter, before you make them. Various commercial products are available. You can get them from most building supply stores. Alternatively, you can make your own retard from wallpaper paste using the recipe below. Paint the inside of your banana box with the retard mixture and allow it to dry. For greater retarding, paint on a second or third coat. Retard Recipe • 3 or 4 level teaspoons of cellulose wallpaper powder • 500 ml water • ½ cup of sugar
Make A Hyper-Tufa Garden Planter 6The Hyper–tufa recipe Now that you have gathered all the tools together, found the boxes for a banana -box mould, made up a mixture of retard and painted the inside of the banana-box, and have all the basic ingredients on hand, you are ready to start making a hyper–tufa garden planter. There are many different recipes for hyper-tufa. These are the two most commonly used recipes: Basic Recipe Stronger Mix • 1 part cement • 2 parts cement • 1 part aggregate • 1 part aggregate • 2 parts peat • 2 parts peat • Water • WaterNOTE: All parts are by ‘volume’ or ‘bulk’ of the ingredient. For example, you could use a bucket as your bulk measure. Then, for the basic recipe you could mix: • 6 buckets of cement • 6 buckets of aggregate • 12 buckets of peat • water
Make A Hyper-Tufa Garden Planter 7Making the hyper-tufa mixture Making hyper-tufa planters is quite hard work. Consider recruiting a helper before you begin. Start with a small quantity for your first attempt! To make the hyper-tufa mixture for your planter using the basic recipe, follow these three steps: 1. Carefully measure out the dry ingredients and put them in the wheelbarrow. 2. Use the large shovel to thoroughly mix the dry ingredients. 3. SLOWLY add a small quantity of water and continue to mix the ingredients thoroughly. Watch carefully the appearance of the mixture while adding small amounts of water and blend to an even grey colour. Pay particular attention to the corners of the wheelbarrow to make sure all ingredients are thoroughly mixed. IMPORTANT Water must be added SLOWLY as you mix the dry ingredients. Thoroughly blend all ingredients until the mixture looks an even grey colour. Be careful not to make the mixture too wet; it should be about the consistency of thick porridge
Make A Hyper-Tufa Garden Planter 8Making a hyper-tufa planter Now that you have finished mixing the ingredients, you can make your first hyper-tufa planter. For the “banana-box planter” follow these five steps: 1. Place the larger cardboard banana-box onto a flat surface and place bricks or concrete blocks around the outside of the box to support the box walls. 2. Place one or more 50 mm wooden spacers (to act as drainage holes in the finished pot) on the base of the banana-box. 3. Shovel in the hyper-tufa mix to the thickness of the spacers, ie 50 mm, and pat the mix flat with your hand.
Make A Hyper-Tufa Garden Planter 9 4. Place the smaller box inside the larger banana-box so that there is an even gap all around of about 50 mm. 5. Fill the inside box with bricks, rocks, soil etc to hold it in place, then fill in the gap between the two boxes with the hyper-tufa mix, tamping down with a piece of stick as you go.
Make A Hyper-Tufa Garden Planter 10Finishing your hyper-tufa planter Leave the planter to set for about 24 hours; longer in winter. Peel off the outer banana-box. Because it will be very soggy by this time, it should peel off easily. Use a high-pressure garden hose to scour the planter walls to expose the texture of aggregate and peat. If water scouring is not effective, you may need to use a stiff brush to scrub the walls. WARNING Resist the temptation to remove the inner box and its fill too soon. Do not try to move the planter; it will break! Wait for at least a week before you attempt to move the planter. After a week or more, you can remove the inner box and its fill. Knock out the 50 mm wooden spacers to provide the necessary drainage holes for the planter. Your planter is now ready for planting! Enjoy!
Make A Hyper-Tufa Garden Planter 11Aging your hyper-tufa planter Hyper-tufa is called a living stone because, in time, a garden of mosses or lichens will grow on the surface. However, this takes time because fresh concrete is highly caustic and inhibits the growth of plants on the surface. In time, the caustic nature of the concrete will disappear with normally weathering. The process can be speeded up by treating the surface with various acids such as sour milk, vinegar, yoghurt, etc. You do not need to buy these specially but when old stock is available, use it. Another technique is to mix up a custard of animal manure and paint it on the hyper-tufa surface. This will not only provide a source of nutrients but may also contain spores or seeds of various plant life. Stir up a sloppy mix in a bucket and slap it on! If you leave your pot in a shady, damp spot, moss will soon grow on the surface. However, if you are forever moving the pot from sun to shade, from damp to dry, then nothing or little will grow. Remember a rolling stone gathers no moss!
Make A Hyper-Tufa Garden Planter 12Glossary of TermsA Paggregate ∙ A mass of inorganic Portland cement ∙ A finely-ground rock-like materials mixed together powder commonly made of a in various combinations mixture of limestone and shale; according to their diameter. used in the making of concrete. It Commonly reffered to as normally develops its design Builders Mix. strength in twenty-eight days.B Rbuilders mix ∙ A mixture of fine retard ∙ A chemical product which and coarse aggregates, usually delays the setting of the concrete containing crushed river-stones mix. and sand. SC scoria ∙ Refuse or slag remainingcaustic ∙ Capable of corroding, or after a metal has been smelted; eating away tissues; burning; loose, clinkerlike pieces of corrosive. volcanic lava.concrete ∙ A mixture of cement, fine aggregate, coarse T aggregate, and water.concretions ∙ The act or process tamping ∙ Forcing down or pack of growing or coming together; closer together by firm repeated solidifying. blows. tufa ∙ A chemical sedimentary rockH composed of calicium carbonate or of silica, deposited fromHyper-tufa ∙ a home-made solution in the water of a spring equivalent of natural tufa rock; or lake. made from cement, aggregate and peat.