Gardening Part Two of the guide on sustainable food ... · ©Sustainable Living 2014 Gardening Part Two Page 1 of 9 Gardening – Part Two of the guide on sustainable food production

©Sustainable Living 2014 Gardening Part Two Page 1 of 9

Gardening – Part Two of the guide on

sustainable food production at home

The previous section of the Sustainable Living learning guide on gardening introduced ways to grow vegetables in your own backyard. This second part looks at maintaining the garden, feeding and protecting crops as they mature and other aspects of a sustainable approach to food growing at home. When working in a study group, do choose beforehand which activities you would like to try, from the options here. Some require more preparation than others and it will be up to the group’s host to decide how much work to put in beforehand, collecting materials. Those activities that you don’t want to try as a group can be read out or left to be tried out by individuals at their homes. Please note the minimum times indicated next to the activity titles and also allow some time if you are including a garden visit.

Maintaining the garden

Now that you have your garden in place, it’s time to look at maintaining it for maximum productivity.

Organic vs. non-organic gardening

Many people are hesitant about ‘organic growing’ and ‘organically grown food’ because they think it is too expensive or doesn’t yield the benefits that are so often claimed. To grow organically is perceived as too complicated and labour intensive. However, the small scale home garden is the perfect environment for this and growing organically is actually cheaper and much less work than you think.

Activity 9: Organic vs. non-organic – discussion – 20 min

Take some time in your group to discuss the benefits and drawbacks of organic gardening, using the following questions:

a. How important is it to grow and buy organically? What

are the benefits?

Published 2014. Lead author Natalie Hormann, with some material from previous editions by Holger Kahl and Rhys Taylor © Sustainable Living Education Trust

Colin and Marilyn tending their vegetable garden - a shared activity with productive results. Fruit trees form the backdrop here.

Lesley’s son Isaac liked home-grown veges from an early age.

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b. What are the disadvantages of growing or buying

organically?

c. If you can’t have both – what is better: local or organic?

Compare the outcomes of your discussion afterwards to the table below. What are your thoughts?

Non-organic growing Organic growing

Input of artificial fertilizer which is based on non-renewable and thus diminishing resources and steadily increasing in price

All fertilizer (compost, bokashi, worm castings, compost teas) can be collected and produced at home at almost no cost

Input of pesticides, herbicides and fungicides – costly, toxic to the environment, birds, bees and – humans!

Use of natural pest control (hand picking, companion planting to attract natural predators, crop rotation, mixed plantings - biodiversity). Use of ‘weeds’ as living mulch or even salad greens. Healthy plants through healthy soil with continuous cover.

Lower level of nutrients in the food as soil becomes more depleted over time

High levels of nutrients due to healthy soils and nutrient ‘recycle’ (composting). Carbon stored in soil and living plant cover.

Peelings and green waste from kitchen or garden is not composted, but disposed of to landfill

All green waste can be reused in the garden

Fewer insects and birds due to the use of chemicals

Steadily increasing population of beneficial insects and native birds who provide pest control (but may still eat some crop)

Unhealthy soils require constant digging and tilling, soil structure deteriorates

Worms do the digging – healthy soils resent tilling! Surface compost is pulled into soil.

Activity 10 - Alternatives to garden chemicals – 10 min

Sometimes it’s hard to think of organic alternatives when dealing with a certain pest or weed. Explore this more through this group activity, before we dive into more detail on pest and weed control. Divide into groups of two or more and pick a topic each – fertiliser, pesticide, herbicide, or fungicide. Brainstorm as many alternatives to chemicals as possible within their topic. These can be ‘additives’ or methods of doing things in the garden. Compare notes after about 5 minutes of discussion.

Jocelyn favours organic food when shopping, so she grows organic veges at home too (these are courgette/zuchinni) Further reading on organics:

Organic vs. non-organic. Six common views on organics explored by the chemists. The bi-monthly magazine Organic NZ is published by Soil and Health Association. Available in shops and by subscription both by mail http://www.organicnz.org.nz/magazine and electronically on Zinio .

Making compost can be as simple

as heaping up the nitrogen-rich garden weeds and mown grass plus high-carbon material (cardboard, paper, twigs) inside metre-square wooden slat boxes…or involve assembling larger ‘hot compost’ covered heaps with manure included to raise temperatures, and in consequence kill more weed seeds. Part-shaded garden or yard space suits all-year compost -making.

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You can then review our downloadable handout ‘Alternatives to Garden Chemicals’ from Sustainable Living website and go through any answers that didn’t come up in discussion

Feeding your plants

Plants need food, no doubt about that. And if you were growing commercially and on a large scale, you would put a lot of thinking into getting just the right mix of nutrient. Luckily, in the home garden, things are simpler. A healthy soil, rich in organic matter, regularly fed with compost and mulched frequently is likely to have a balanced mix of nutrients and a neutral soil pH level. Serious nutrient imbalances rarely occur under these conditions, especially if you mix your plantings or follow a basic crop rotation scheme.

Crop rotation

This refers to planting different types of plants in one area sequentially over time. There are a number of reasons why this is a good idea, particularly to aid disease and pest control, and maintain nutrient levels and there are lots of different crop rotation patterns and theories on what works best. One that’s easy to remember and works for us, is based on the availability of nitrogen in the soil:

LEGUMES (Beans, Peas, Lupins – anything with pods) are first. They add nitrogen to the soil via hosting nitrogen-fixing bacteria in their root systems (you can see the ‘nodules’ where they live on the roots). Nitrogen is important for leaf growth, so, the best following crop for that enriched soil is: LEAFY GREENS AND STEMS (Spinach, Silverbeet, Kale, Broccoli, Cauliflower and other brassicas, also winter leeks ) – producing lots of leaf growth based on the excess nitrogen. They are best followed by heavy-feeding Mediterranean crops: FRUITING SUMMER CROPS (Tomato, Zucchini, Pumpkin, also sweetcorn). These still need lots of nutrient from compost, but the excess nitrogen available directly after legumes might make them grow only leaf, not fruit. Once these are finished, they are best followed by: ROOT CROPS (carrot, parsnip, beetroot, potato, also summer onions and garlic) these don’t form successfully if too much nitrogen is present, so starve them by planting them last. Then start the cycle again, adding fresh nitrogen by planting legumes… Or add manure once the roots come out.

Clarify new technical terms found whilst you learn, e.g.

dynamic accumulators (deep rooting plants such as comfrey and plantain, which bring up useful minerals from the subsoil that are otherwise unavailable to plants);

Insectaries or 'beetle banks' (strips of land planted with plant species which flower to attract beneficial insects in summer and physically shelter them in winter, to emerge in spring and control pests);

'false seedbed' technique (clearing a bed, allowing weeds about three weeks to germinate, clearing seedlings again by sharp hoe or flame, then sowing or planting without further digging, so that other weed seeds are left below the surface).

The nitrogen cycle within soil is

explained simply at link here The same diagram by Mike Jones with more chemistry, is online here. Mineral supplements

Because minerals take a while to become available to plants after being added to soil, it helps to add rock phosphate to the soil after growing legumes so that it will be available to the following two crops in the rotation. If your soil is deficient in any trace elements (perhaps Boron, Selenium?) add these at the same time. Seaweed is a good source of trace elements: but wash off salt first. Keep notes of rotations

You’ll need four roughly equal sized garden bed areas to run a four stage crop rotation. Keep a list or a diagram to note what you grew in each bed last season, in this one, and what you plan to grow next season. The plants that have similar food needs, along with their companion herbs and flowering plants, are known as a ‘guild’ in permaculture gardening.

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But even the best soil can become a bit nutrient-diminished, so an on-going feeding regime can be helpful: Feed may be liquid or solid. Liquid feed to soil and leaves is a very important tonic in the organic food garden. It helps keep the immunity of your plants high while they are working hard over the growing season. It’s a handy tonic for any plants suffering pests, disease or stress. Worm-farm or bokashi-bin drainage liquids both make fantastic garden fertilizer, once diluted – or you can make your own ‘fertilizer tea’:

Activity 11 – Making liquid fertilizer ‘tea’ – 15 min

This activity can be set up very quickly if you have your materials ready. Note that it needs to soak (steep) for a couple of weeks before you can use it. If you collect enough sacks and contents, you can make up bags for participants to take away dry and submerge at home. Materials:

40 l drum / barrel (make sure it’s clean and read label to check it hasn’t had any nasty chemicals in it previously)

Hessian bag or coffee sack

Some rope or bailing twine

A long branch or pole and a stirring stick

Choose from: comfrey, stinging nettles, seaweed, fish waste, manure, compost, weeds, grass clippings (or all of the above)

How to make it: 1. ¾ fill your drum with water, preferably rainwater to avoid chlorine.

Fill a sack with your chosen mix of ingredients, add a little unsulphured molasses

2. Lay a pole across the top of your barrel. 3. Tie the sack to this pole on rope long enough that the sack is well

submerged in the water 4. Leave a second big stick standing in your barrel so you can give it

a good stir each day. Stirring helps to get air in – a faster alternative is to bubble in air using an aquarium air pump.

5. Cover with a lid or net curtain to keep flies out, but let air move. 6. Brew for 2-3 weeks (less if using a pump), then dilute to the colour

of weak tea and apply at once, straining it first if you use a sprayer rather than watering can, to avoid blocking the spray-jet. If you have only used plant-based materials, you can spray the mix onto the leaves; manure-based brew is for soil application only, to keep bacteria off your crop.

7. Refill with water once to keep the sack submerged, and it will make more compost tea.

8. Be aware that it may become smelly –so pick a spot to stand it on which will not upset anyone nearby.

Solid fertilizers:

Leafy green crops in these beds at New Brighton Community Garden

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There are many philosophies on digging, but if your soil is clay-based, digging can make matters worse unless you add sand, gypsum or lime at the same time. You can apply solid fertilizers (like manure, compost, sea weed, coffee grounds, pea straw, rock phosphate and trace minerals) by just layering them on top of your soil under your mulch layer. Earthworms will do the digging-in for you. If you are feeding your garden in this way, there will be no need for artificial nitrogen fertilizers – which means cost savings for you and less stress for the environment!

Weed and Pest control

Once your garden is up and flourishing, you may encounter some unexpected or uninvited visitors seeking to share your crop. In this section, we will discover how to deal with them.

Activity 12 – What weed is that? – 20 min You can do this activity in several ways: either in advance, invite your group members to bring some samples of common weeds they encounter in their garden; or you’d go for a walk around your plot together and collect a variety of specimens today. Try to identify what you are finding - start with the weeds you know and share your collective knowledge. If you have online access or a few books on weeds around, collect a few samples of the weeds that no one can identify and see if you can find them on the Massey Weed database http://www.hortinfo.co.nz/factsheetlists.asp?id=f6084cce0351d80460f9. Once you have identified something new you could try to ‘Google’ its medicinal or culinary uses – you might have come across a new salad ingredient, or it might be toxic! An overview website on edible weeds: http://www.juliasedibleweeds.com/edible-weeds/

In an organic garden, there are very few ‘weeds’ – most are better referred to as ‘unwanted’ plants in their particular location. Many can serve for medicinal or culinary uses, or feed chickens (check first on which are toxic to chickens though), use as compost input or where they grow can be used as indicators for soil health (see above link http://www.permaculture.org.nz/node/67). Due to their particular characteristics, weeds often complement the soil they grow in by adding just the nutrients the soil is lacking. They can also help protect the soil nutrients by keeping it covered in between ‘wanted’ crop plants and especially helpful for over-winter retention of nitrogen. A weed cover is better for soil health than uncovered, bare soil. Leaving weeds in place where you haven’t added other protection (such as mulches of pea straw, straw, grass clippings or paper) is better than exposing an area of living soil to the impacts of wind, sun and rain. Plants rarely compete in the root zone – they will compete for light though. Rather than pulling out weeds (which can disturb the roots of the precious plants you are trying to grow, doing more harm than good) it can be useful to cut the weeds off at the surface, but leaving their stems in place as a green

Further reading on feeding plants & soil: weblinks from POD gardening.

Sharon hoeing weeds in the spring. “Catch them early before they set seed, or you will have them all year.” Useful weed identification books from libraries: A Guide to the Identification of NZ common weeds in colour, by E A Upritchard and Weeds of Crops and gardens in NZ by R L Taylor. See also from libraries: A Field Guide to the Native Edible Plants of New Zealand by Andrew Crowe, and Simply Living – a gatherer’s guide to NZ fields, forests and shores by

Gwen Skinner

Clover is often present as a weed and brings the advantage of being a nitrogen-fixer, enhancing the soil.

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mulch – or just letting them grow and putting up with the ‘messy’ look while making sure your veges win the competition for light by applying a vigorous ‘height pruning’ regime. An interesting alternative for soil preparation and weed control can be found here: http://www.dirtdoctor.co.nz/uploaded/file/Urban%20Eden%20Handout.pdf If you are dealing with invasive visitors or weeds are threatening to take over (creeping buttercup for example) rather than spraying the area, try finding out more about what conditions the particular ‘weed’ likes – and work on creating the opposite. Buttercup for example grows in wet, dense, acidic and compacted soils. Adding organic matter and sand (for airflow), avoiding tilling and adding lime to balance acidic conditions will eventually change the properties of the area to a point where the weed plant ‘moves out’ on its own account - permanently.

Activity 13 – More soil analysis – 10 min

In the group, discuss what weeds are the most invasive and most common for each participant. Compare with the above websites and investigate together what this might mean for the soil they grow in and how these conditions could be changed to deal with these weeds (e.g. Acidic, compacted soil could be loosened by adding lime and lots of organic matter, and not leaving it exposed to the winter rain)

Invasive weeds like bindweed/convolvulus or oxalis are quite often made worse by trying to remove them, as they will regrow from every bit of broken root that is left in the ground. Controlling them by cutting them off just below the surface (and thus depriving the plant of light) but not breaking up the root and then mulching or changing soil conditions can be a better long-term control. More interesting reading on organic weed control techniques can be found here: http://www.cefs.ncsu.edu/resources/organicproductionguide/weedmgmtjan808accessible.pdf If you feel you do need to spray for weeds (for examples weeds in cracks in paved areas), try the following:

- White vinegar: this can be painted on the weeds with a foam

paintbrush, but must be kept away from other plants as it will kill most

plants (which is why it is used for pickling).

- Boiling Water: Boil some water, and immediately pour it over weeds

– or use a flame weeder to wilt them

- Vinegar and Salt: For stubborn weeds, try diluting a few teaspoons

of salt into some white vinegar and pouring a small volume of that

direct onto your weeds. Please note that this concoction will kill just

about any plant it comes in contact with, so don’t let it run, to keep it

away from your other plants, as well as your lawn.

Other weeds, such as daisy, below, have no such advantages for the soil, and if you catch them before seeding are easily removed.

Sustainable Living course members being shown the purple flowers (Phacelia) and the orange flowers (Calendula) that are being grown at New Brighton Community Garden as companion plants for the food crops. They provide nectar and pollen for both crop-pollinating bees and for beneficial natural pest-control insects such as lacewings, ladybirds and hoverflies (see pic below), whose larvae, hatched from eggs left on the crop leaves, are all voracious eaters of aphids!

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- Organic Interceptor is an organic certified spray made from pine oil

(and smells like it, persistently)

- Vigilant is a gel that can be painted onto cut stumps of woody weeds

to kill the roots. Useful for persistent stumps of ivy, gorse, barberry.

Pests

Biodiversity is the best form of pest-control. A healthy, diverse plant system will rarely create problems. Some insects (e.g. the cabbage white butterfly) identify their host plants by sight, so mixed plantings where each vegetable is surrounded by different shapes and smells (companion plants like onions, marigolds/calendula are helpful here) will be safer from pests than a monoculture block of vegetables all of the same sort. Scented herbs are also good veg garden companions. Adding flowering host plants to feed predatory insects with nectar (e.g. Phacelia, Alyssum) is another good means of controlling pests. Adding bird life by planting native food plants in hedges nearby or attracting other predatory animals (e.g. by adding a small pond for frogs) can be another helpful tool.

Activity 14: Biodiversity planning

On the map of the property you created previously, identify areas you could use for planting native trees and shrubs. Don’t limit yourself to the backyard: consider incorporating the front yard, the road berm or adjacent / nearby reserve or bush land. Be aware of the height that plans may reach and anticipate the shade they create. If you have a creek/stream close by, consider including some restorative planting there, even if it’s on public land (where you’ll have to ask the Council directly or via local conservation groups for advice and permission). Try to find a spot for water: even if this is just a bird bath or a tyre pond (instruction on how to construct one can be found here: http://treeyopermacultureedu.wordpress.com/chapter-13-aquaculture/tyre-pond/). Water features will attract birds and frogs – all of which are great helpers in pest control! They may also attract mosquitoes, so watch out for this side-effect. A great project for the kids can be the construction of a weta hotel (instructions can be found here: http://www.greenurbanliving.co.nz/imagelibrary/2.pdf). A pile of twigs and leaves in a corner of the garden could be a home to hedgehogs (helpers in slug control but they also eat lizards and may raid birds’ nests!). Bumble bee ‘hotels’ are another interesting project: they are based on collections of hollow tubes such as wider diameters of bamboo.

Margaret and daughter Maia replaced their bath with a low-flow shower (she’s holding the new shower head, here) and the old bath went into the garden as a pond for wildlife – it’s surrounded by shrubs to give it cooling shade in summer.

Audrie keeps chickens as part of her garden ‘system’. This year there were chicks hatched, too. Chickens are great insect eaters.

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For those who are keen (and spend most of their time based at home), consider incorporating chickens into your garden design – they are useful both for pest and weed control, but need to be carefully managed. A moveable coop, called a ‘chicken tractor’ is a way to utilize hens to scratch, weed and fertilize the ground, eliminating slugs, snails and insect eggs in the process. More information can be found here: http://www.nzlifestyleblock.co.nz/2012/04/permaculture-in-motion-chickens-in.html. By Google searching ‘chicken tractor’ you will come across a myriad of different possible designs to match your style and garden space.

Crop rotation (as above) is another important tool in pest control. Rotating plant families year by year will keep pest populations and diseases in check. It will also enhance the health and vigour of the vegetables you are trying to grow, making them less prone to insect infestation. Bringing chickens onto the ground between crops is another way to clean up soil of insects that eat plant roots – but keep those same chickens away from your seedlings! However, if you do have to spray, try the following (any of these could be mixed as part of this learning workshop, for participants to take home) Against greenfly (aphids) and red mites:

- Tomato leaf spray: Chop up two cups of tomato leaves and let steep

in 2 cups of water over night. Dilute with another cup of water the next

morning and spray carefully onto plant leaves. It works because the

alkaloids in the tomato leaves (and the leaves of all nightshades,

actually) are fatal to many insects. Do not spray directly onto edible

parts of crops.

White butterfly caterpillars:

A bacteria is available to kill the small caterpillars when they ingest it

on brassica leaves, but is harmless to both people and to useful insects such

as bees. Called BT (Bacillus thuringiensis), and sold under brand names

Thuricde and Dipel, it is used in horticulture, so the best value for home

gardeners is to buy to share between a group. Mix with water and spray.

Whitefly, aphids, most sap-sucking beetles - Garlic Oil Spray: Three to four cloves of minced garlic into two

teaspoons of cooking oil. Let the mixture sit overnight, and then strain

the garlic out of the oil. Add the oil to a litre of water, and add a

teaspoon of biodegradable dish soap. Store in a bottle or jar, and

dilute the mixture when you use it by adding two tablespoons of your

garlic oil mixture to one litre of water. Don’t apply on a sunny day, and

not to salad greens.

Mites:

- Hot Chilli Pepper Spray: Mix two tablespoons of hot pepper sauce, a

few drops of biodegradable dish soap, and one cup of water and let it

Hens are more useful than roosters in urban gardens, as the noise from roosters disturbs you and neighbours (and may be covered by Council By Laws)

Don’t mistake this bug for a pest on your crops – it’s the larvae of a ladybird, purple and yellow-spotted (rather than red with black spots), and larger than the aphids it eats. Your sprays may deter useful insects such as these.

White butterfly (illustration from RR Scott, Lincoln University) Plant disease controls

The best bet in disease control is prevention and a healthy environment (this goes for humans, too!). Biodiversity, healthy soil and keeping moisture levels right are all important. Using organic, disease-resistant seed and removing already diseased plant material from the garden (not even composting it) also goes a long way. Fungal diseases can be controlled by ensuring sufficient airflow around plants (especially important for

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sit overnight. Use a spray bottle to apply the spray to infested plants.

Reapply when necessary. Do not use on salad greens, though!

Aphids, mites, thrips: - Simple Soap Spray: Just add one tablespoon of dishwashing soap to

3 litres of water and spray the mixture on the pests. Far preferable to

pyrethrum, which may harm bees.

Slugs / Snails:

- A bar of chocolate: Don’t laugh. If you or your neighbours have

children around, the most efficient means of controlling slugs and

snails is to set a prize for the most slugs collected. Send the kids out

at dusk on a rainy day (especially after a long dry spell), each armed

with a torch and a small bucket of hot water. Slugs and snails will

come out at night when it is damp and climb to the top of the plants,

where they can easily be picked off. The person who picked off the

most slugs will win the bar of chocolate. (Natalie says “Our record

was 568 in one evening! One or two of these missions will solve your

mollusc problem!”)

- Beer traps (sunk into the ground, with the liquid levels below the soil

surface) will work by drowning the attracted slugs. Note these will

have to be refilled after each rain. Slats of timber laid down between

your plants in the garden can work as well: The slugs will hide

underneath these by day and all you have to do is go around regularly

and scrape the critters off the underside of these hiding places into a

bucket of water– at least you know where they will be now! Large

citrus rinds placed rind side up will do the same job (dunk rind in very

hot water and pour onto compost afterwards, including the slugs).

Rabbits, birds:

- Red Pepper Spray: Mix four tablespoons of Tabasco sauce, one cup

of water, and one teaspoon of dish soap. The capsaicin in the pepper

spray will irritate the animal pests, and they'll look for less spicy fare

elsewhere. An alternative is a mixture made from dried egg and

water-based glue, which is very smelly – best used on native plant

seedlings and shrubs, not food crops.

tomatoes!). Variety helps control the effects of viral diseases – growing more than one variety of any plant will prevent a total loss of harvest, as rarely will all plant varieties be affected equally. If you do still have problems, try the following:

- Milk (or whey, if you are a

yoghurt or cheese maker)

will control powdery mildew

- Baking Soda Spray:

Combine one tablespoon of

baking soda, one tablespoon

of vegetable oil, one

tablespoon of dish soap and

3 litres of water and spray on

the leaves of mildew-

susceptible plants.

And as a general tonic for any struggling plant:

- Comfrey tea: Steep

generous amounts of

comfrey leaves in a bucket

of water for one week, then

use it up (it gets very smelly

if left too long). Spray on

plants as a foliar fertilizer.

Compost tea or seaweed tea

will work, as well (stir daily)

Further reading on veg-gardening more sustainably:

Earth user’s guide to permaculture. Rosemary Morrow. 2006. Hyden House, UK. (or previous Australian 1994 edition from Kangaroo Press) The NZ Organic Gardening Handbook. Brenda Little.2000.Reed, NZ. Companion Planting. Bob Flowerdew. 2010. Kyle Cathie, UK Homegrown fresh veges-A practical guide. Lynda Hallinan, 2010 .NZ Gardener (not organic, but still informative)