By GEOFF MIERS
Potatoes are warm season plants so now is the time to plant them as the frosts are gone.
Potatoes can be planted out twice a year, a little like tomatoes. Potatoes are best planted late August to late September and again in January and February.
Potatoes are adaptable to various soil types however they do require good draining soils. They do best in friable soils with good structure. They also do well in no dig gardens and can be grown even in bales of hay.
Potatoes are grown from tubers generally available from nurseries in late winter to early spring. For planting complete tubers should be 30 to 60 grams in weight. Cut larger tubers into pieces with each piece having at least one eye or sprout. Three kilos of tubers are capable of producing up to 60 separate plants.
When purchasing potato tubers leave them in a warm shady spot for two to three of weeks allowing them to start to sprout. If your seed potatoes have already sprouted they can be planted immediately.
Large tubers cut into smaller pieces should be left for several days after dicing allowing the cut surfaces to dry well before planting, reducing the likelihood of them rotting once planted.
If planting in a traditional vegetable garden dig the soil to spade depth, mark out planting rows 75 cm apart and trench them out to a depth of 15 cms. Scatter a good organic fertiliser along the bottom of the trench and turn in with a little extra soil added so the trenches at now 10 cm deep.
Place tubers 25 to 40 cms apart and where tubers have been cut into pieces ensure the cut surface is placed down with the eyes facing upwards. Cover the trench back to soil level. Sprouts should emerge in three to weeks. Keep soil moist but not continuously wet.
As the plants emerge you can gradually add extra soil hilling around the plants to ensure the forming potatoes are not exposed to the sunlight. Potatoes exposed to sunlight will turn green and green potatoes are poisonous.
Potatoes require little extra fertiliser provided a balanced NPK organic fertiliser has been added to the soil prior to planting. Allow plants to develop fully and flower.
Three to four weeks after flowering it is possible to harvest “new potatoes” although many gardeners tend to leave plants until they start to die-off at which stage it is possible to harvest fully mature potato tubers.
There are many varying ways to grow potatoes. You can grow them traditionally in a prepared garden bed in good friable soil, you can grow them in no dig gardens and you can grow them in “special tyre potato garden beds” and its possible to grow them in straw.
For a straw garden approach prepare the soil as indicated above place your tubers 2.5 cms into the soil and fill the trench with 15 cms of straw. As the potatoes emerge 15 cms above the straw add more straw until only three cms is visible. You can repeat this several times.
Each time you add a layer of straw you are inducing the plant to produce new roots coming off the main trunk of the plant. The more roots produced the more tubers.
Tyre gardens are a great way to produce potatoes particularly where space is at a premium. Prepare the soil initially by trenching, tilling and blending in an organic fertiliser before planting the tubers. As they emerge and grow to 15 to 20 cms add soil or straw around the plants leaving the tip exposed.
Once the tyre is filled add another tyre and continue to repeat the process again adding a third tyre. You can build up the soil level around the potato plant using straw and compost or soil with a sprinkle of organic fertiliser added.
I’ve seen other ways of imitating the tyre garden approach. A panel of bamboo or even solid panels can be put in place to form walls. Soil, compost and straw can be added to a depth of 50 cms, the tubers are planted and 10 to 15 cms of soil is added. As the plants emerge you gradually add more soil/compost or straw until you raised garden bed is filled.
Another easy method is to use chicken mess and several stakes. Simply prepare your soil and plant as detailed above inside a circular ring of chicken mess. As the potatoes emerge and grow add layers of pea straw and compost always leaving several centimeters of green foliage above the layer you have added.
This is an easy low cost to construct method and once the plants have matured and commenced to die off you simply remove the wire mess frame allowing for an easy to harvest operation.
Once tubers are harvested remove damaged tubers (use them immediately) and store complete tubers in a dry, cool spot in hessian bags, wooden crates or wire baskets.