Oxalis tuberosa - Oca

Latin plant name Oxalis tuberosa Common plant name Oca Plant type Perennial herbaceous plant Size (meters) < 1m Distinguishing features The plant is not known in the wild, but populations of wild Oxalis species that bear smaller tubers are known from four areas of the central Andean region. Oca was introduced to Europe in 1830 as a competitor to the potato. Oca is cultivated primarily for its edible stem tuber, but the leaves and young shoots can be eaten as a green vegetable also. Andean communities have various methods to process and prepare tubers, and in Mexico oca is eaten raw with salt, lemon, and hot pepper. Oca is fairly high in oxalates, concentrated in the skin, and the bioavailability of oxalate appears to be similar to spinach. Oca is one of the important staple crops of the Andean highlands, due to its easy propagation, and tolerance for poor soil, high altitude and harsh climates. Oca needs a long growing season, and is day length dependent, forming tubers when the day length shortens in autumn (around March in the Andes). In addition, oca requires climates with average temperatures of approximately 10 to 12°C (range: 4°C to17°C) and average precipitation of 700 to 885 millimeters per year. In areas with harsh winter climates, early frosts may cut back the foliage before the tubers have a chance to form. In tropical areas where the days are unchanging in length, oca will not set a crop successfully.

Planting a tree

To plant a tree we need to dig a hole three times the size of the pot of the tree.

Once the hole is digged we will untighten the roots of the tree so they do not go circular and they can grow properly.

We will put some water into the hole to see if it drains. If it does we put some compost on the bottom, if it does not drain we will place some pebbles or sand and then the compost.

We lay the roots on the hole and cover with soil avoiding to leave air in the middle.

We press the soil on the top and put some more compost over it.

We can stake the tree to help it grow straight even if there are hard winds. We will place the stake on the side of the dominant wind, at a distance of 20cm of the tree and we will tie the stake to the tree with rubber cords to allow the tree to have flexibility when it gets the wind.

Never stake a tree longer than two years. Its root should develop properly to give enough strength to the tree to hold by its own roots.

The tree we planted is a cherry tree.

Planting cuttings

When we take cutting from a plant we should plant them in the next half an hour. We can put them in water till we work with them.

Before planting them we can deep the cutting into rooting compound first.

We will have to create the proper mix of soil to put into the pot. It should contain:

• Soil
• Sand
• Compost
• Vermiculate or perlite

Once we have the mix we will fill the potts and plant the cuttings in the perimeter of a pot.

The cuttings should be in the pot at least for one year and then we can move it to another pot where they should be another year. After two years they can be moved to their final place.

Pruning a tree

Scar in the bark due to wrong pruning

When we prune a tree we have to be careful not to make scars on the bark. If the pruning of a branch is done to close to the bark, it will leave a scar in the bark and the inner part of the trunk will be exposed to air, therefore to fungi and roteness.







When pruning a branch we should always leave at least 2-3 cm of the branch out of the trunk, so when the bark reabsorbes it, does not make any scar in the tree.

Proper pruning leaving 2-3cm of distance to the trunk

How it should look after pruning

Scar due to a too tight staking of the tree

Other scars in the tree may be done by a bad staking. It we stake the tree too tight or with a hard material that is not rubber, the wind will make the string rub the bark and cause a scar like the one shown in the photo.

School hedge

We have planted a hedge to give some shelter to the school orchard.

We used:

• 6 rosa rugosa
• 6 berberis purpurea
• 7 cotoneaster bulatus
• 21 privet legostrum
• 22 Common Holly

That is a total of 62 plants that will allow as to have a double row of 31 plants each.

The lenght of the hedge is 6meters+15 meters that makes a total of 19 meters.

19/31=0.6m=2 feet

The distance between the plants will be of 2 feet in each of the two rows with a gap of 1 foot in between both rows.

With a string and some pegs we marked the position of each of the plants on each of the two rows.

We divided into three groups, one will dig square holes, the other will do round holes with the auger and the last will dig a trench.

TRENCH WORK

AUGER HOLES


SQUARE HOLES

Identifying nearby plant

We collected branches from trees near our homes to identify them in the classroom

Silver maple

Pine tree

Ash

Compost

Here are some tips on how to create a good organic compost:

Compost ingredients

1. 'Greens' or nitrogen rich ingredients

• Urine (diluted with water 20:1)
• Comfrey leaves
• Nettles
• Grass cuttings

2. Other green materials

• Raw vegetable peelings from your kitchen
• Tea bags and leaves, coffee grounds
• Young green weed growth - avoid weeds with seeds
• Soft green prunings
• Animal manure from herbivores eg cows and horses
• Poultry manure and bedding

3. 'Browns' or carbon rich ingredients - slow to rot

• Cardboard eg. cereal packets and egg boxes
• Waste paper and junk mail, including shredded confidential waste
• Cardboard tubes
• Glossy magazines - although it is better for the environment to pass them on to your local doctors� or dentists' surgery or send them for recycling
• Newspaper - although it is better for the environment to send your newspapers for recycling
• Bedding from vegetarian pets eg rabbits, guinea pigs - hay, straw, shredded paper, wood shavings
• Tough hedge clippings
• Woody prunings
• Old bedding plants
• Bracken
• Sawdust
• Wood shavings
• Fallen leaves can be composted but the best use of them is to make leafmould

4. Other compostable items

• Wood ash, in moderation
• Hair, nail clippings
• Egg shells (crushed)
• Natural fibres eg. 100% wool or cotton

5. Do NOT compost

• Meat
• Fish
• Cooked food
• Coal & coke ash
• Cat litter
• Dog faeces
• Disposable nappies

How do I make my compost?

You can make compost simply by adding compostable items to a compost heap when you feel like it. It will all compost eventually but may take a long time and if the mix is unbalanced, may not produce a very pleasant end product. With a little extra attention you could improve things dramatically. 

An ideal mix

To make good compost you need a more or less equal amount of 'greens' and 'browns' by volume. You can also include small amounts of the 'other ingredients' listed above.

How to manage our compost

1. Gather enough material to fill your compost container at one go. Some of this may have been stored in a cool heap and have started to rot slightly. Make sure you have a mixture of soft and tough materials.
2. Chop up tough items using shears, a sharp spade (lay items out on soil or grass to avoid jarring) or a shredder.
3. Mix ingredients together as much as possible before adding to the container. In particular, mix items, such as grass mowings and any shredded paper, which tend to settle and exclude air, with more open items that tend to dry out. Fill the container as above, watering as you go.
4. Give the heap a good mix within a few days, the heap is likely to get hot to the touch. When it begins to cool down, or a week or two later, turn the heap. Remove everything from the container or lift the container off and mix it all up, trying to get the outside to the inside. Add water if it is dry, or dry material if it is soggy. Replace in the bin.
5. The heap may well heat up again; the new supply of air you have mixed in allows the fast acting aerobic microbes, ie those that need oxygen, to continue with their work. Step 4 can be repeated several more times if you have the energy, but the heating will be less and less. When it no longer heats up again, leave it undisturbed to finish composting.

 

In our school garden we turned the compost to give it some air.

A link to know more about compost

http://www.organicgardening.com/learn-and-grow/cold-weather-compost

Plants for a school garden - educational space

Field trip to Deelish Garden Center

Plant name Type Reasons for suitability Eucalyptus darlympleana Tree evergreen Low maintenance Peeling bark Aromatic Fast growing Carex (Sedges) - on the back Ophiopogon planiscapus 'nigrescens' (Blackgrass) - on the front Evergeen perennial Grass Appealing sense for its sound under the wind Hydrangea Deciduous shrub It flowers during the autumn when school starts The dried flowers can be used for crafts Daffodils Spring flowering herbaceous perennials It flowers during spring Low maintenance Sense appealing (colours, beauty,...) Lavander Herb Sense appealing (scent, aromatic, colours)

Plants suitable for challenging environments (wind, extreme temperatue changes)

Field trip to Deelish Garden Center

Plant name Type Reasons for suitability Helleborus Herbaceous evergreen perennial  flowering plants It flowers in christmas time Hardy plant Frost resistant Acanthus spinosus spinosa Herbaceous No serious  insect or disease problems. Hardy plant Pothinia - Red robbin Evergreen shrub Hardy plant Tolerant to winter Leaves turn red in winter Attractive Tolerates full shade Somewhat drought tolerant once established Viburnum Evergreen shrub Evergreen Easy maintenance Hardy Scently flower Ecucalyptus tree Evergreen tree Hardy Colourful bark Italian alder Decidious tree Hardy tree for exposed areas Atracts bird life Garlic Vegetable Stands low temperatures during the winter Artichokes Perennial thistle Winter hardy They can be grown almost everywhere Can survive between 90-100 days of frost over the year

Some ideas for plants for special places

http://www.dyg.ie/forum/plants-places

Plants for window boxes - hanging baskets suitable for a shop front display

Field trip to Deelish Garden Center

Plant name Type Reasons for suitability Primula Flowering herbaceous plant Colourful Aesthetics It flowers during spring Petunia Flowering plant Colourful Aesthetics It flowers during spring Vinca minor Evergreen trailing It covers the bottom part of the baskets Colourful during spring until mid summer Ornamental cabbage  Ornamental vegetable Evergreen Colours Compact. It fills the space Alpine strawbery Herb Small Colourful Flowers and berries Covers the spaces

Some ideas for plants for special places

http://www.dyg.ie/forum/plants-places

Plants for a shelterbelt enclosing a big site

Field trip to Deelish Garden Center

Plant name Type Reasons for suitability Griselinia littoralis Evergreen hedging shrub Hardy plant suitable for an expose site Evergreen Lets part of the wind go through without blocking it, what would create turbulences Olearia traversii Evergeen hedging shrub Fast growing Coastal tree Stands exposure to the sea salt Austrian pine Coniferous evergreen tree Hard tree that can grow up to 20 - 55 meters It is flexible so it will not block the wind but will protect from it

Some ideas for plants for special places

http://www.dyg.ie/forum/plants-places

Helianthus tuberosus - Jerusalem artichokes

Latin plant name Pteridium esculentum Common plant name Jerusalem artichokes Plant type Herbaceous perennial plant Size (meters) <1,5 - 3 m Distinguishing features It has opposite leaves on the lower part of the stem. The leaves have a rough, hairy texture The flowers are yellow, member of the daisy flower. The tubers are elongated and uneven, typically 7.5–10 centimetres. They are edible, a little bit tasteless. They need to be They will die during the winter and grow next year. It is hard to get rid of them. They are good to soften the soil.

In the garden we had some Jerusalmen artichokes. We cleared them and got the tuburs to plant for the next season.

Preparing the beds for the winter time

School garden beds after being prepared

When the winter is coming we have to prepare the beds that we will be using in spring. The steps:

1. Clear the bed
2. Take away ant put into the compost all the dead plants and weeds
3. Modify the pH with lime if the bed is too acid with sulfur or wood chips if it is too alkaline
4. Cover with a net or plastic
5. Hold the cover so it doesn't blow with the wind

Comfrey

Comfrey (also comphrey) is an important herb in organic gardening. It is used as a fertilizer and as an herbal medicine. 

Comfrey is a particularly valuable source of fertility to the organic gardener. It is very deep rooted and acts as a dynamic accumulator, mining a host of nutrients from the soil. These are then made available through its fast-growing leaves (up to 4-5 pounds per plant per cut) which, lacking fibre, quickly break down to a thick black liquid. There is also no risk of nitrogen robbery when comfrey is dug into the soil as the C:N ratio of the leaves is lower than that of well-rotted compost. Comfrey is an excellent source of potassium, an essential plant nutrient needed for flower, seed and fruit production. Its leaves contain 2-3 times more potassium than farmyard manure, mined from deep in the subsoil, tapping into reserves that would not normally be available to plants.

There are various ways in which comfrey can be used as a fertilier. These include:

• Comfrey as a compost activator - include comfrey in the compost heap to add nitrogen and help to heat the heap. Comfrey should not be added in quantity as it will quickly break down into a dark sludgy liquid that needs to be balanced with more fibrous, carbon-rich material.
• Comfrey liquid fertilizer - can be produced by either rotting leaves down in rainwater for 4–5 weeks to produce a ready-to-use 'comfrey tea', or by stacking dry leaves under a weight in a container with a hole in the base. When the leaves decompose a thick black comfrey concentrate is collected. This must be diluted at 15:1 before use.
• Comfrey as a mulch or side dressing - a two-inch layer of comfrey leaves placed around a crop will slowly break down and release plant nutrients; it is especially useful for crops that need extra potassium, such as fruit bearers but also reported to do well for potatoes. Comfrey can be slightly wilted before application optionally but either way, avoid using flowering stems as these can root.
• Comfrey potting mixture - originally devised to utilize peat, now environmental awareness has led to a leaf mold-based alternative being adopted instead; two year old, well decayed leaf mold should be used, this will absorb the nutrient-rich liquid released by the decaying comfrey. In a black plastic sack alternate 3-4 inch layers of leaf mold and chopped comfrey leaves. Add a littledolomitic limestone to slightly raise pH. Leave for between 2–5 months depending on the season, checking that it does not dry out or become too wet. The mixture is ready when the comfrey leaves have rotted and are no longer visible. Use as a general potting compost, although it is too strong for seedlings.

In the school garden we prepared liquid comfrey fertilizer. We cut the leaves of the comfrey and stuffed them into a 'tea bag' that we left inside a container for two weeks. After those two weeks we took our the 'tea bag' and let the comfrey liquid in the container for future use.