When it comes to Irish potatoes, most people think of Idaho or Maine, but Irish potatoes can be grown successfully right here in South Florida.
While the weather is still comfortably cool, it’s a good time to prepare your backyard garden to grow a winter crop of Irish potatoes. January is a good time to prepare the planting beds. Pick a high spot in your garden that will receive full sunlight. It is important that the soil be richly loamy, but well-drained. Very sandy soils are less suitable, because they lack enough humus to retain moisture during the growing season. Add muck or peat to sandy soil to achieve proper loamy planting beds. Prepare raised planting beds in rows about 12 to 16 inches high and 2 feet wide.
Irish potatoes require a complete fertilizer in most soils. A fertilizer containing 3 to 5 percent ammonia, 6 percent phosphoric acid and 5 to 6 percent potash will give excellent results. The fertilizer should be applied in one or two applications. One application before planting is recommended. The fertilizer may be either broadcast into the soil or drilled-in. This should be done ten days or more before the seed potatoes are to be planted. Two applications are recommended on sandy soils or in cases when heavy rains have leached out the first application. The second application should be drilled into the sides of the planting beds.
The best seed potatoes come from Maine. The seed varieties that give the best results in Florida are Spaulding’s Rose 4, Bliss Triumph and Irish Cobbler. Spaulding’s Rose 4 is the favorite for winter planting. It is a smooth potato that grows rapidly and matures early. Use only seed potatoes that are certified as “disease-free.” Cut the seed potatoes into quarters with two well-developed root eyes in each piece to be planted. The seed potatoes should be planted in rows every 12 to 16 inches and covered about 3 inches deep.
Irrigation will be needed if rainfall is only average or below average. When rains are frequent, and the soil is deeply prepared and in good condition, irrigation may not be necessary. In unusually dry seasons, potatoes will stop growing unless they have sufficient moisture.
Irish potatoes require frequent cultivation to conserve soil moisture and to remove weeds. When rainfall is plentiful, frequent cultivation is necessary to keep the soil in a loose condition and to hasten the growth of the plants. Grass or weeds rob both moisture and fertilizer from the soil, and must be removed. When the first potato plants break the soil surface, it is advisable to cultivate the top of the beds to loosen the soil around plants. Remove any plants that show signs of disease, such as water-soaked spots on leaves which later become dry, brown or black in appearance, circular blight spots on the leaves, or wilting of whole plant stems.
For harvesting, it is not necessary that the potatoes be thoroughly ripened. When the crop has reached a desirable size, and the tuber skins slip on pressure of the thumb, the potatoes are ready to harvest. If the crop has had no setbacks, it should be ready to harvest 80 to 90 days after planting. If the potatoes are to be used for seed, they should be allowed to remain in the ground until the plant tops are mature. The tops usually die down about 120 days after planting, and growth of the tubers stops.
Plant now and you could be enjoying your own home-grown Irish potatoes by St. Patrick’s Day.