Lesson 8 – Part A: CARING FOR YOUR GARDEN
Lesson 8 – Part B: PROTECTING PLANTS FROM COLD
Lesson 8 – Part C: HEAT AND WIND PROTECTION
Lesson 8 – Part D: FIND-A-WORD PUZZLE
PREPARATION FOR LESSON 8:
Please read through Lesson 8 text for students.
This lesson may, at first glance, seem very long, and it may seem odd to include both heat and cold protection in the same lesson. However, average winter temperatures in far northern Australia are higher than the average summer temperatures in Melbourne and Launceston. Winter provides the best temperatures for growing a lot of popular vegetables and fruits in the north, despite low rainfall and high UV levels.
Schools in many warm areas will not need cold frames or cloches, and schools in cool and cool-temperate areas may not need to protect their garden from extreme heat in summer. You should select from this lesson only what is appropriate for your local conditions at this time.
Part A of this lesson continues general garden maintenance, including weeding. Watering and mulching gardens was covered in Lesson 7.
Encourage students to regularly check on the growth rate of plants. If extra fertiliser is needed, assist them to prepare liquid fertiliser at the correct strength. Seedlings respond quickly to foliar feeding but it does not encourage strong root growth if plants regularly obtain fertiliser through their leaves. A gentle watering after applying liquid fertiliser is more beneficial, and applies the organic gardening principle of "feed the soil, not the plant".
Some garden vegetables benefit from a little extra fertiliser at certain stages of their development. Advice on when to apply any extra fertiliser can be found under the relevant month in 'Your Gardening Diary' in Easy Organic Gardening and Moon Planting pp 67-121, or in the individual cultivation notes for that species of plant.
WEEDING
Encourage students to weed their garden area regularly, and dispose of weeds as advised in the text.
Try to avoid weeds with seed heads going into the compost bin in case the compost does not get hot enough to kill the seeds.
If you are unfortunate enough to find perennial weeds such as onion weed or nut grass in the garden area, cut them off at ground level. As students learnt in Lesson 2, plants produce most of their energy for growth from photosynthesis. If you repeatedly cut off the foliage of these weeds, the bulbs will weaken and die. If you dig or pull them out, you will only increase the problem because tiny bulbils that form new plants release from the parent bulb when it is disturbed.
Please avoid the use of herbicides in garden areas. Some of the serious soil diseases that students learnt about in Lesson 6 are far more common where herbicides are used to kill weeds.
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Part B of this lesson is for schools in areas where winter frosts can damage plants or cold weather can delay spring growth. Because the school year ends mid December, sowing vegetables in cold frames or using cloches in early spring will allow students to enjoy produce before the end of the school year.
COLD FRAME
Cold frames don't have to be fancy, expensive or permanent. In many areas of Australia cold frames are only necessary for several weeks of the year, and a structure that can be easily dismantled is more practical for school grounds. This simple cold frame in the lesson is easy to put together and to dismantle when the weather warms. Bricks do not have to be cemented or glued. The bricks and window panels can be stacked in the corner of a shed or storage area until next winter.
If you are concerned about the use of glass panels, a piece of thick, lightly coloured plastic can be glued to a simple timber frame instead of using an old window.
Choose a responsible student to be a cold frame monitor and cover the cold frame in the afternoons and uncover it in the mornings. The cold frame can be left partially covered at weekends. It will lose some heat where the glass is uncovered, but seedlings will be less damaged by cold than they would be in the open air.
CLOCHE
If your school needs to make cloches, an adult should cut the lengths of wire, or dowelling and polypipe for supports, especially if your class consists of junior primary students. Fencing wire (4 mm diameter) is strong enough to support cloche covers. Fencing wire is fairly easy to find at the local recycling centre in rural areas, but in metropolitan areas it will probably be easier to use polypipe and some wooden dowelling. Support hoops should have a generous curve so that foliage of the seedlings closest to the edge of the bed does not come in contact with the plastic cover, as this will result in cold being transferred from the plastic to the plant.
For wire hoops, cut the wire 1.6 times the width of the bed, and push the ends of the wire into the soil. Polypipe can be cut 1.5 times the width of the bed. Support the hoops on 30 cm lengths of dowelling, pushed halfway into the soil.
Although cloches are only necessary for short periods in cool weather, use lightly coloured, UV-resistant plastic sheeting as a cover because some plastic sheeting may break down into flakes in sunlight. Larger nurseries sell plastic sheeting by the metre. The plastic sheet should be long enough to cover the seedling area plus a metre at each end.
The anchoring method for the ends of the sheeting will depend on the thickness and flexibility of the plastic. Stiff plastic can be folded at the ends and anchored with a brick or rock. Thin sheeting can be tied in a loose knot and anchored with a piece of bent wire. Leave the ends of the cloche open at weekends, in case unusually warm weather occurs.
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If you need to provide heat protection for your garden, 30% shadecloth supported by arches (as shown in the photo) is a popular method of providing this. Arches can be positioned high enough to suit most crops and they allow good air circulation around plants. However, setting up this type of sun protection is a job for adults.
Hoops are made from 38 mm diameter plastic irrigation pipe that is the right diameter to slip over the ends of wooden garden stakes. Star stakes require the more expensive, heavy-duty 51 mm polypipe for arches, or the 38 mm polypipe can be lashed to the star stakes instead of slipping it over the ends. Support posts are spaced, in pairs, 1.5-2 metres apart along beds.
TIP: If using wooden garden stakes, pay the little extra and buy the pointed ones. They are easier to keep straight when driving them into heavy or stony soil.
The formula for the lengths of pipe to form each arch is half the width of the bed multiplied by 'pi', plus twice the length of the pipe to extend onto the stakes. However, cutting the pipe to one and a half times the width of the bed plus 70 cm is a good general guide for most garden beds. For example, if beds were 80 cm wide (a good width for primary students), pipe for arches would be cut into 190 cm lengths.
The shadecloth is cut to the length of the area it is to cover plus one quarter of a metre. An 11 cm hem is turned in at each end and fixed with a basted hem 8.5 cm from the folded
edge.
In the photo to the left, garden twine was used to show stitching. However, this is not very durable and heavy nylon twine or heavy duty fishing line sewn with a bagging needle is a better choice to baste the hem.
The arches at each end of the bed can be slipped through the hem to anchor the shadecloth. Lightweight knitted shadecloth has eyelets along the edges. Thread pieces of strong twine or cord through holes along the edges of the shadecloth to tie the cover to the tomato stakes.
The sun's orbit is at its highest position around December 22nd (our Summer Solstice), and then moves slowly northwards in the sky through January and February (our hottest months). As schools are in recess during the second half of December and all of January, shadecloth can be positioned slightly longer on the north side of the beds.
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BAD WEATHER ACTIVITIES
When the weather is too hot or cold for working outdoors, and there is a suitable undercover area available, students may enjoy activities such as building a scarecrow for their garden or making a 'tool board' for their garden storage area. Tool boards are a handy reminder to return tools and equipment to storage after each lesson. Place a sheet of plywood or pegboard on the floor and arrange the gardening tools on the board in a direction that will provide support when the board is upright. Students can draw the outline of the tools on the board with a permanent marker. Nails or hooks can be inserted to hold the tools in position when the board is fixed upright.
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This puzzle includes some of the words that students encounter in their gardening lessons and may be a suitable activity for students when weather is unsuitable for gardening. As mentioned in the Introduction (under additional resources) there are other fruit-and-vegetable-related puzzles available at www.freshforkids.com.au
PUZZLE SOLUTION
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