When to Water Established Plants in Dry Weather

Flowering

Eg pea, bean, potato, sweetcorn.

Fruiting

Eg pea, bean, sweetcorn, courgette, marrow, tomato.

Edible leaves

Eg lettuce, spinach, summer cabbage. Tip:plants can otherwise grow slowly or ‘bolt’ (flower prematurely)

Roots or bulbs

Eg carrot, beetroot, onion, radish.  Tip: every one to two weeks so roots don’t ‘split’ when it rains by taking up too much water and expanding too quickly.  Too much water produces excess leaves with no extra yield. 

Rarely necessary

Eg Brussels sprout, broccoli (sprouting), winter cauliflower, spring cabbage.

Useful watering techniques

• Water in the morning or early evening (less water is lost to evaporation).
• Conserve moisture by adding organic matter to soil, eg compost.
• Water beneath leaves to wet the soil. Wet leaves can be scorched in sunny weather.
• Water seedlings with watering cans or hoses with ‘rose’ ends.
• Collect and use rainwater, eg install water butts for sheds. This reduces the environmental impact and cost of using mains water.
• Remove weeds as these compete with plants for water. 
• Water more often in windy weather as plants will dry out in these conditions.
• Keep compost moist, never wet. Check after watering, eg compare the weight of pots or remove the odd pot to see if the root ball is moist throughout. 
• If compost in pots is very wet and smelling bad, carefully remove compost from around roots and re-pot.
• Check if outdoor containers need water even after rain. Dense foliage and ‘rain-shadows’ from buildings can stop water getting to the soil.
• Submerge dry wilted pot plants in a bucket of water for an hour.
• Plants also wilt when too wet or if attacked by root rots or soil pests.

Health and Safely Guidelines Part 3

Use of hand tools
Young people should be taught the correct way to use tools and basic health and safety aspects. It is perfectly acceptable for young people to use a normal set of hand tools but make sure that the equipment is not too large or heavy for them to use safely.

Using tyres as growing containers 
Garden Organic does not recommend using tyres as containers in the garden. Tyres are made for road use and have been tested for that purpose. They are not manufactured as plant containers and so no thorough trials have been done on safety in this context. Research from the USA and Australia has shown that there is the possibility of zinc contaminating the soil as tyres degrade. Experiments have also been conducted using ground rubber as part of potting media and this has resulted in plant death.

The only firm conclusion we can draw at this time is that zinc in tyres can be toxic to plants. How much zinc or other contaminants leach from tyres and at what stage of decomposition they become a hazard to plants we do not know. We also have no research to show what levels of contaminants are hazardous to humans. Our advice is that it is better to use a different material known to be safe such as untreated wood, plastic or terracotta.

Poisonous plants
Many plants in the garden may be toxic in some way and it’s important not to become overly cautious about this but take a practical view. Teach pupils not to put any plants or berries in their mouths and always check with an adult before eating any produce. Make pupils aware of any plants that could cause discomfort or injury such as stinging nettles, plants with thorns or hooks (eg roses, brambles) or sharp leaves (eg pampas grass).

Water
Never let pupils out of sight near water, whether a lake or pond. Wherever possible, fence off the area or install a steel mesh across a pond.

Watering Plants

Good watering is an essential gardening skill. It’s important to use the right amount of water, at the right time, for most benefit to your plants. This is good organic gardening – using this precious resource wisely when plants need it most. A few tips make your time spent watering really count.

When plants need most water

Seeds

Need water to trigger germination by soaking into the seed coat. Tip:Keep compost in pots and trays moist. Water seeds in the soil at sowing and again in dry weather.

Seedlings

Will quickly stop growing without moist compost or soil.  Tip:Water especially after thinning and potting on.

Young plants in pots

Keep compost moist. May need daily watering in hot weather and when in a greenhouse or on a windowsill.

Tip:Big plants in small pots dry out more quickly. ‘Re-potting’ into a larger pot helps.

Young transplants

Easily dry out when first transplanted outdoors or into containers, reducing growth and ability to ‘establish’ quickly.Tip: Water well before transplanting and thoroughly in dry weather, eg every 2-4 days.

Bigger plants in containers

Rely on you to keep the compost moist as the roots cannot spread into the soil.  Tip:Smaller volumes of soil dry out more quickly. Use larger containers (eg half barrels) and a mix of topsoil with compost when potting for drainage and moisture retention.

How to water plants in the soil

Watering with large amounts, less often, is better for plants growing in the soil. This encourages plants to search for water deep into the soil, making them tougher and more independent. By contrast, watering little and often is not good practice (eg daily). This encourages shallow roots and vulnerable plants that need more water from you in dry weather. Remember that a wet soil surface can hide a dry soil beneath! 

Transplanting Young Plants

After thinning and potting on seedlings, you should be left with vigorous young plants ready to transplant into their final location in the soil or a container to grow to maturity. You might also be transplanting bought plants.

Why transplant

Transplanting suits plants that need large spacing, eg cabbage plants can be transplanted into the soil from pots or a seedbed when 10cm tall to 30-45cm apart. This is rather than sowing seed direct into their final location. In this way, transplanting allows you to make the most of available space, eg you can grow quick maturing crops such as radish or raise other plants before you need the soil/space for containers for the transplants. Transplanting doesn’t suit crops that need very close spacing or longer root vegetables, where sowing direct and thinning is usually best instead.

How to transplant 

The trick with transplanting is to minimise ‘transplant shock’ by being gentle. You should also harden off plants to gradually acclimatise them to the new growing environment, eg from a windowsill or greenhouse to the colder outdoors. Without this step, plants may be damaged by the sudden change in growing conditions, sometimes slowing growth for several weeks or even dying.

Potting On Seedlings

Seedlings grown in pots and trays sometimes need potting on before being transplanted into their final location in a container or the soil. This inbetween stage gives seedlings the extra space and compost they need to continue growing strongly. Two similar techniques are explained here: ‘pricking out’ and ‘potting on’. 

Pricking out

This technique moves seedlings from one small container to another, usually from pots or ‘seed-trays’ to larger pots or modular trays where seedlings can grow on individually rather than in clumps. This is done before seedlings become overcrowded and while still small so the roots aren’t too entangled. Many gardeners choose not to prick out, preferring to sow seed direct into pots or modular trays to save time and the risk of damaging seedlings. However, this extra stage is useful on the following occasions:

• When unsure of the likely germination rate, eg where poor germination in modular trays would leave a lot of wasted space.
• For getting as many seedlings as possible, where every seedling is needed and grown on.
• When there isn’t space to sow direct into modular trays, eg where the space for raising plants is already full.

Potting into larger pots

This technique gives seedlings in their own pots or modular trays more space to grow, eg pepper and tomato plants need re-potting several times. This builds up the plant’s strength before transplanting into a large final container or into the soil. Potting on may also be necessary if there is delay in transplanting (to keep plants growing strongly). 

Thinning Seedlings

After sowing seed, you may have more seedlings come up than you need. A few extra plants are useful in case of losses by pests and diseases or when unsure about how many plants you need. Too many seedlings though, growing too close together, produce weak plants. The surplus needs to be removed, using a simple technique outlined below.

Why thin seedlings?

Seedlings restrict each other’s growth when overcrowded. They stretch up to compete for light, making straggly plants rather than short, strong ones ready for potting on or transplanting. The trick is to thin seedlings before they compete too much so you’re left with the right number of vigorous plants capable of producing a crop. 

The process of thinning 

Thin in stages, leaving the sturdiest and most vigorous seedlings at the correct spacing. It also helps to practise good seed sowing (A18) so enough germinate as a back-up, but plants aren’t wasted unnecessarily. Sometimes gardeners are reluctant to remove healthy seedlings. Luckily, you’ll see the benefit once the remaining plants grow on strongly. Thinnings can be eaten or added to the compost heap.

Needless to say, wash hands after handling compost and soil.

Sowing Seed

Growing plants from seed is one of the most important and rewarding techniques for gardeners to learn. Once mastered, sowing seed is an easy and cheap way of producing all sorts of plants quickly, whether vegetable, herb, edible flower, ‘green manure’ or even fruit.

Choosing seed varieties
Start with good quality seed, ideally organic. Buy new each year or use seed saved by fellow gardeners. Choose plant varieties that suit the following:

• Your available sowing and harvesting times, taking into account school holidays
• Pest and disease resistance
• Flavour, type and reliability of variety

What seeds need to germinate

1. Temperature Wait until the recommended month for sowing indoors or out (see seed packets and Food Growing Instruction Cards). You can also check the soil temperature using a soil thermometer.
2. Moisture Soil or compost should be moist, but not wet. Seed won’t germinate when dry, while too much moisture may cause them to rot and encourage fungal diseases.
3. Light Many seeds will germinate in either dark or light conditions. Once germinated, seedlings need good light or they will become pale and straggly.
4. Sowing depth Generally, cover large seeds with sieved compost or soil no deeper than twice their size. Very small seeds should be left uncovered or with a thin layer of vermiculite (very fine mineral rock). 
5. Soil or compost Use organic, peat-free potting compost or a well-prepared soil with crumbly surface ‘tilth’.

Be careful when handling seed, compost and soil, washing hands afterwards. Ensure appropriate adult supervision.

Holiday Care of the Garden

The school holidays can be a difficult time for garden care, particularly in summer in unpredictable weather. Some plants will run to seed if not picked; others produce giants (courgettes) or become coarse and tough (beans). In dry spells, plants can stop growing, or die completely. Weeds will also grow quickly. It’s best to have a plan.

Involving the community

Involve the garden club and community volunteers to create a rota for picking produce, watering and ventilating greenhouses. Volunteers are also helpful to keep on top of weeding. Have clear responsibilities among the group and a few contingency plans.

Your school may also have a caretaker and/or site management team who would be willing to help in the holidays. It’s even better if some pupils and parents can continue to help with the garden, giving them the satisfaction of seeing the plants right through the season. Whoever helps, make sure they are thanked and recognised, maybe through the school newsletter and website.

Harvesting

Ideally choose crop varieties that can be sown or harvested either side of school holidays. See Food Growing Instruction Cards and the Organic Gardening Catalogue. Before a holiday, harvest all the crops that are ready. Others will last through the holidays if they were well cared for earlier and are growing well, eg pumpkins, potatoes and winter cabbages. Other crops will need regular attention, eg watering and picking tomatoes, courgettes and beans. 



Weeding
Covering the soil surface with a ‘mulch’ is a great way to suppress weed growth by excluding light. Mulches include water-permeable membrane and thick layers (5-10cm) of organic matter such as leafmould (rotted leaves). Grass clippings are also useful, but don’t use clippings from grass treated with weed killer.


Watering
Learn how to water plants during the holidays to get the best harvest with the least amount of time and water. For example, once young pea plants are growing strongly, only water after they start flowering to ‘swell’ the pods. Watering beforehand produces leafy growth without any increase in yield. By contrast, plants like Brussels sprouts rarely need watering once established unless there is prolonged dry weather.  When you do water, apply it where plants need it, at the roots. Water thoroughly, but less often. This discourages surface rooting that will be dependent on you for water and vulnerable to drought (far more than deeper roots). You can also conserve moisture using the same mulches as for weed control (above). Mulch wet soil to help ‘lock in’ the moisture beneath, watering beforehand if needed.


Using green manures
Sow seeds of green manure if you have areas of bare soil, eg after harvesting crops. These useful plants keep the soil covered to suppress weeds and conserve moisture. They also hold on to plant nutrients in the soil to stop them from leaching and improve structure and fertility when dug in. 


Ensure anyone helping in the garden during holidays is aware of school access and safety procedures and familiar with specific known hazards in the garden. Always inform the school site manager about what’s happening.

Making Paths and Surfaces

Space for walking is as important as space for growing plants. You need a network of safe access routes all year round between garden features like sheds, water supplies, buildings, gates, compost heaps and growing area. Match the construction method and surface to your garden and users.

Path and surface materials

Grass

Grass paths can be laid or made when digging new beds in a lawn. Like a lawn, they need looking after (eg watering, feeding, mowing, etc). Grass can die when trodden on too much and the surface may become muddy.

Bark chips

Pieces of bark are available cheaply in bulk. They are quick to lay in any shape and provide a dry surface unless the soil beneath is very wet. Bark slowly rots and needs topping up every couple of years, though less often when laid on a ‘water-permeable membrane’.

Gravel

Gravel is available in different sizes and colours, providing an all-weather surface. It is reasonably priced and quick to lay in any shape, but its extraction/quarrying is not very environmentally friendly. 

Paving

Paving includes brick, natural stone and concrete slabs. Paving creates all weather surfaces, but is more expensive, requiring proper foundations to be safe and durable. The extraction/manufacture is not very environmentally friendly; try reclamation yards.

Choose a surface that allows safe access for all users. If unsure about the construction, consult a builder. Follow Manual Handling guidance when moving bulky materials.

Health and Safely Guidelines Part 2

Weather condition
In sunny or hot weather make sure that people wear hats and sunscreen to avoid sunstroke and burning. It is also important to have an adequate supply of fresh drinking water to avoid dehydration. If possible work in a more shady area of the garden. It is still possible to garden in cold, wet weather when wearing appropriate warm, waterproof clothes, with possibly an extra pair of socks and Wellington boots. If the weather is too rough, there are indoor activities that can be done instead, eg cleaning pots or making labels.

Land contamination
There are very few areas in the UK where this is a concern. If you suspect a problem, contact your Local Authority who are responsible for this. If land is contaminated, this does not prevent a school from having a garden as Garden Organic support schools to grow using containers as an alternative.

Using food grown in the school garden for school dinners
We recommend hand washing facilities are available. Separate facilities with running water are required for cleaning produce. There is no need to wash garden produce in any type of sterilisation fluid.

Composting food waste
Do not compost meat, dairy or cooked food as this can attract vermin. There is little evidence of risk to human health by exposure to bioaerosols (see B7.2 for definition) from domestic composting. However, if someone is susceptible (eg suffers from asthma), make sure they are not close by when turning or disturbing a compost heap.

Vermin
Good housekeeping should help to prevent this problem. Keep growing and composting areas tidy
and don’t leave rubbish lying about. If you suspect that rats are present contact your Local Authority Environment office. Ensure that compost bins are maintained correctly. Rats, dogs and foxes may visit a compost heap if they are already in the area but composting does not generally attract vermin in the first place. If rats or mice are nesting in your compost heap, this may be a sign that the heap is too dry. Add water until it has the consistency of a wrung-out sponge. You may still find instances where they nest and rummage in wet heaps but this is not common.

Weil’s Disease, also known as Leptospirosis, is a rare, but serious, disease carried by rats. It can be contracted by exposure to water or wet surfaces that are contaminated by rats’ urine. It is highly unlikely that pupils would come into contact with such contaminated environments whilst going about their normal gardening activities. Young people should be reminded regularly to wash their hands thoroughly and not to put their fingers in or near their mouth. The incubation period is usually 7-12 days. Symptoms include fever, chills, muscular aches and pains, loss of appetite and nausea. In the later stages there may be bruising of the skin, sore eyes, anaemia, nose bleeds and jaundice. If symptoms appear, contact a doctor.

Sheds and Tool Storage

A shed is a great asset in the garden. Big or small, they’re dry hideaways for garden tools and gardeners alike. A few tricks can make using a shed - new or inherited - far simpler. Proper tool storage also makes life easier and extends the working life of your valued tools.

Buying and using sheds

You’ll probably only need a small shed, but buy bigger than you think you’ll need. Extra storage space will always be helpful as gardening activities and events develop. Even small sheds can include workbenches for sowing seeds. Look for a strong construction to withstand heavy use and all weathers. Weak designs are easily damaged and may flex and leak. Make sure any inherited sheds are structurally sound before use. Speak to the school’s site manager about the security of the shed and for advice on construction and location. You could even design and make your own shed. It’s possible that a school supporter might donate or sponsor a shed.

Tool storage

Store tools for safety and quick access. One of the easiest methods is to hang tools with handles on the wall with hooks or brackets. This leaves the floor clear from trip hazards and tools are easy to reach. Try boxes for smaller tools like trowels and lockable metal cabinets for more valuable items like secateurs. You may decide some tools are better stored in the school.  Clean off soil and plant debris from tools before storing. Clean any tools that have been used to work with diseased plants very thoroughly to prevent cross contamination. Wipe any metal parts with an oily rag to keep clean and free from rust. Store in dry place.

Sheds should be part of your garden risk assessment before use. Be careful of swinging shed doors and uneven surfaces in and around the shed.

Removing Weeds and Grass

Once you have chosen your site, you’ll need to remove any weeds and grass before planting your fruit and vegetables. There are several organic methods for instant and slower clearance which don’t use weedkillers (‘herbicides’). These are shown below.

Removing weeds (ie any plant growing where you don’t want it)

Remove ‘perennial’ weeds by digging over the soil to lift out as much root as possible. These plants have thick (often deep) roots and can survive for several years. They include dandelions, dock and brambles. 

Perennials can regrow from the smallest bit of root so you may need to dig two or three times to remove the regrowth - though you may never completely remove the most persistent perennial weeds (like bindweed and ground elder). 

If there is time (and to avoid digging), cover the soil with ‘light-excluding mulch’ such as black plastic for 6-12 months. The weeds beneath die without light and leave the soil ready for planting after surface cultivation. You can even plant vigorous crops like potatoes and marrows through the mulch while the weeds are dying. 

Remove ‘annual’ weeds by digging out with a garden fork or covering with light-excluding mulch for a few weeks. They have only small roots and the plants die after setting seed in the first year. Annual weeds include groundsel and chickweed.



Removing grass
Just like weeds, grass is easily killed by covering with a light-excluding mulch. Grass is also easily dug up using a spade to cut the roots beneath the soil surface. Lift and remove the grass as ‘turves’.  If grass is growing weakly and very patchy, it can be simply killed by digging over the soil to bury the plants. However, this doesn’t work if the grass is vigorous, where grass left near the surface after digging is likely to quickly regrow. In this instance, remove turves or mulch as above.


How much to remove
Only clear the space you need for the first year’s fruit and vegetables. Any bare soil left unused will be quickly overtaken by new weeds. You can help keep the soil clear by the following:

• Sowing or planting newly cleared soil with crops as soon as possible.
• Hoeing as soon as weed seedlings appear.
• Covering with a light-excluding mulch.
• Sowing ‘green manure’ (plants grown to benefit the soil).

Be careful when handling weeds. Many have sharp, rough, or sticky growth and the rootballs can be heavy. Follow safety guidelines for garden tool use and digging, together with Manual Handling guidance if lifting turf and moving wheelbarrows.

Growing on a Windowsill

A windowsill offers a wealth of opportunities for growing a wide range of plants. This invaluable ledge of narrow space is ideal all year round for starting off seedlings and growing smaller plants to maturity. The sunniest windows face south; north is shady, but a window facing in any direction offers opportunities.

What to grow on windowsills

Grow any plants that appreciate the extra warmth are suitable for windowsills. It may be the only place you have to raise seedlings before they move outdoors (after ‘hardening off’ to acclimatise them). Windowsills also offer a permanent home for herbs such as basil. You could also try vegetables that like warmer growing conditions, eg tomatoes and peppers.

Looking after plants on a windowsill 

• Water windowsill plants just as you do for outdoor containers. In other words, only water as needed by the plant, keeping soil moist but not wet. The most common cause of death for indoor plants is overwatering.
• Keep plants from touching the window surface to avoid leaf damage.
• Because light only comes from one direction, plants tend to stretch towards the light. ‘Even-up’ the growth by regularly turning plants so the other side faces the light.
• Stick a piece of plain white paper onto the window during the middle of the day to protect seedlings from getting ‘scorched’ by hot sun (especially if on a south facing window).

Keep plants on windowsills away from food preparation areas so that soil/compost and plant debris do not contaminate food.

Container Growing Techniques

Filling containers

Since containers are larger than pots and usually more permanent (a home to plants for months or sometimes years); they a need a special ‘growing medium’. The ideal mix combines the following.

• Compost, either home-made or bought organic, peat-free potting compost.
• Good quality ‘topsoil’, either bought or from a spare pile in your garden from digging out paths or a stack of rotted grass turves.

The topsoil is fertile and moisture retentive, but alone compacts too much. The compost ‘lightens’ the soil and boosts fertility, but alone can dry out quickly and is difficult to re-wet. The soil also adds weight so tall plants are less likely to topple over in windy weather. 

Feeding plants in containers

As plants in containers are relatively restricted compared to plants in open soil, they benefit from added fertiliser (more often for hungrier plants). Try liquid organic feeds like ‘comfrey’; either make your own or buy from the Organic Gardening Catalogue. For more permanent planting, like fruit trees, replace the top 5cm of soil annually with home-made compost (‘top-dressing’).

Watering containers

Keep the growing medium in containers moist, but not wet. Water every day in hot or dry weather (often twice). Plants will also need more water when in flower or fruit and in windy weather. Check whether you need to water outdoor containers even after rain, as dense foliage and ‘rain-shadows’ from buildings can stop water reaching them. Water under the foliage to reach the roots rather than leaves. Wet leaves can be scorched in sunny weather.

Be careful when handling containers, empty and full. Follow safe practice for handling soil, eg cover open wounds; wear gloves if necessary; wash hands; keep tetanus vaccinations up to date.

Growing in Containers

Many big or small fruit and vegetables will grow well in containers; anything from carrots to cucumbers and flowers to dwarf fruit trees. The trick is to experiment to see what grows best and always look after them.  The confined space of a container means that plants depend on you for watering and feeding.

Choosing containers 

Getting the best container size Choose containers as deep and wide as possible, but still practical to fill with ‘growing medium’ and move when they’re full. Smaller containers tend to dry out quickly and are less suitable for big plants as they limit root growth. 

Choosing container materials

Try any new, reclaimed, or recycled material that is sturdy enough to hold the growing medium. Make sure it’s frost proof and not contaminated with chemical residues, eg avoid tyres. Good options include wooden half barrels, old buckets; large plastic and terracotta pots; window boxes; and so on. Use your imagination!

Ensure good drainage

Drainage is critical. Water will otherwise collect at the bottom of a container and saturate the soil. The roots may then rot and the plants die. Add 1-2cm wide drainage holes if the container doesn’t have any (at least five per 30cm2). Improve drainage by putting a 5-10cm layer of broken pots, gravel or grit at the bottom of the container. Broken-up polystyrene is a lightweight alternative and good recycling. Standing containers on ‘feet’ to lift them off the ground also improves drainage (bought or made from bricks). 

The Pro's and Con's of Raised Beds

Benefits

For gardeners

• Can look after plants and harvest whatever the weather using clean paths and without treading on the soil.
• Reach the soil comfortably from both sides, making it easy to look after plants.
• Easier to know where to walk, helping to avoid squashing plants and compacting soil.

For Growing

• Minimal soil compaction of air pockets and drainage channels. This improves yield and reduces the need for digging (compared with traditional plots that are dug yearly with soil trodden on to tend plants).
• Plants can be grown closer together in beds, often giving higher yields. The denser plant canopy also discourages weeds.
• Improve the drainage of ‘heavier’ wetter soils like clay. 
• Soil improvement (eg adding compost) is concentrated on the growing area and not wasted on paths. 
• Crop rotation is easier to organise when plants are in beds, ie growing plants in different areas of soil  each year to avoid nutrient deficiencies and the build up of soil-borne pests and diseases.•
• Easier to use crop protection methods such as cloches.•
• The height of taller raised beds may help deter low-flying pests like carrot root fly.

Drawbacks of raised beds

• Cost of materials and amount of work involved to make.
• Soil at the bed edges often dries out quickly, especially on ‘lighter’ sandy soils.
• Slugs have a habit of hiding at bed edges ready to eat crops.
• If beds are edged or raised, the design layout is relatively inflexible once built. The alternative to beds is growing plants in containers or using a flexible open soil layout without permanent paths.

Be careful not to trip over raised bed edges. Wooden edges in particular can be slippery when wet and may give splinters.

Growing in Raised Beds

Garden ‘beds’ are narrow strips of soil divided by access paths. They’re often edged or raised with wooden or plastic boards and can be used for growing on open ground and hard surfaces. This section looks at design options and the benefits and drawbacks of raised bed growing.

Design at a glance

Height

Low beds around 15cm high with mounded soil. Sometimes edged to help keep the soil in place. Taller beds up to 60cm with edging; height useful when bending is difficult and for wheelchair users. Customise bed height to suit user age and ability.

Length

180-240cm is usual. It avoids walking too far to reach the other side of the bed and reduces the temptation to tread on (and compact) the soil by hopping across.

Width

90-120cm is usual. It avoids overstretching from the paths or having to tread on the soil to reach the middle.

Paths

At least 30cm wide; 60cm for wheelbarrows and wider for wheelchair access. Paths of bare soil need regular weeding and can become muddy. Use grass or make paths with a bark chip, gravel, or paving.

Edging

Plastic boards, stone, and wood not treated with preservative.

Shape

Usually rectangular, but design your beds to fit the space.

Location

Can be built directly onto soil or a hard surface such as concrete/tarmac. Beds are best in open sunny locations, ideally orientated north to south so plants receive an even amount of sunlight through the day. This also minimises shadows from taller crops.

Soil

Low beds shouldn’t need extra soil after digging and/or adding organic matter. Taller beds will need extra ‘topsoil’ from a spare pile in your garden or bought (around £80/tonne; check quality first if possible). No ‘organic’ topsoil is available. Don’t fill beds with just compost as this will decompose, sink rapidly and dry out too quickly.

Feeding

Feed using the same organic methods as for open soil, eg adding compost.

Typical Soil

Good

Mixture of different sized soil particles (‘loams’), plenty of organic matter and living organisms. Water drains freely, yet soil is moisture retentive. Soil is fertile, with good air content (not compacted).

Needs help!

Excess of one soil particle size, waterlogged or too free draining. Little organic matter and few living organisms. Soil has low or unavailable fertility. Compacted with little air. Often unimproved clay, very sandy soils, and those treated with a lot of artificial chemical fertilisers.

Basics of feeding soil 

Different soils need different fertilisers and crops vary in their needs. Fortunately, adding organic matter such as well-rotted manure and home-made compost is a remedy for most situations. These wonderful materials add the three main nutrients plants need. These ‘mineral ions’ are nitrogen (N), phosphorus (P) and potassium (K), known as ‘NPK’. They are also a source of ‘trace’ minerals, eg zinc and iron. Importantly, organic matter also develops the soil structure and encourages living organisms.

Adding more fertiliser 

‘Concentrated’ fertilisers are widely available, but unlike organic matter, don’t usually develop the soil structure. Instead they are best used to remedy specific nutrient deficiencies in the soil and for plants growing 

in containers. Those suitable for use in organic gardening include plant-based products such as comfrey liquid and animal based products, such as pelleted chicken manure or ‘hoof-and-horn’.  Organic growing doesn’t use artificial chemical fertilisers as their use doesn’t support and enrich natural soil systems.

Be careful when handling soil. Cover open wounds, wear gloves if necessary, and wash hands. Keep tetanus vaccinations up to date. Be aware that soil and organic matter can be dusty when dry and slippery when wet.

Building Soil Fertility

Well cared for soil is the foundation of organic growing and a priority for providing plants with fertility. The below introduces how to develop your soil to grow healthy crops using organic methods. These apply whether growing in open ground or raised beds. There is also guidance on feeding plants.

Understand soil

• Particles of weathered rock (soil ‘texture’), mostly clay, silt and sand
• ‘Organic matter’ (turns into ‘humus’), dead/decomposing plants/animals
• Living organisms, roots, worms, fungi, bacteria, other micro-organisms
• Air and water, in spaces between soil particles; drainage channels

The top layer of soil is most important for plants. This ‘topsoil’ has the most life and fertility - and where gardeners make the most difference.



Test your soil. Assess former cultivation

• Identify soil texture and main characteristics, eg drainage and fertility
• Estimate organic matter and living content
• Assess compaction and drainage (typical air and water content) 
• Measure the relative soil ‘acidity’ or ‘alkalinity’ (pH)

Start building soil fertility: Develop its structure

Add organic matter

Eg two shovels of compost per square metre. Boosts fertility; adds air; encourages living organisms; improves drainage (clay soil) and water retention (sandy soil).

Digging over soil

Quick way of adding organic matter and horticultural grit; reduces compaction (adds air/improves drainage).

Alter soil pH

Minor shifts in pH are possible by adding natural substances, eg dolomite limestone. This helps prevent some plant diseases, eg liming deters ‘clubroot’.

Keep improving your soil

Continue adding organic matter annually and dig as needed. Build and maintain soil fertility by using crop rotation and ‘green manure’.

Look after your soil once improved

Avoid wasting fertility and damaging soil structure, eg minimise cultivation and limit compaction by not treading on soil.

Where to Grow Plants: Design the Garden Layout

Draw a scale map

Mark the features you want to keep or remove. Add the location of preferred amenities and pencil in new features. Try using a computer for revising the design or sheets of tracing paper over a template outline. When designing your garden, slowly refine your needs by talking to the teachers, pupils and community.

Be careful when exploring possible growing areas. In particular, look out for prickly plants and weeds, wet soil and pools of water, hidden objects in long grass and damaged garden structures.