Square foot gardening isn't just for crops that grow above the ground. Consider using a square foot garden to grow delicious potatoes as well. Here are some points to consider when planting potatoes in an intensive, raised bed (4X4 square foot garden).
Where to Get the Seed Potatoes
Buy seed potatoes from most garden supply centers in the early spring. Be sure that they are certified seed potatoes. Don’t take a chance with potatoes purchased from a market, as these are likely to have been sprayed to prevent eyes from forming and will not result in satisfactory planting in square foot gardening.
Step 1: Prepare Seed Potatoes for Planting
Cut the seed potatoes into several pieces, depending on the size. Usually, about four pieces (quartered) is best, but make sure each piece has 2 to 3 eyes in it. Allow the cut pieces to dry out in the sun for a few hours prior to planting.
Step 2: Prepare the Square Foot Gardening Space
If the existing square foot garden already has soil, remove about 6 inches of it and spread 2 inches of compost on the bottom. Place the potato chunks on top of the compost. The rich organic compost will encourage the roots of the potato to develop.
Step 3: Cover the Seeds with Compost
The next step is to cover the seed potato pieces with about 1 inch of compost.
Step 4: Backfill the Holes
As the potato starts to sprout through the compost, once or twice a week cover it with more compost. Repeat this process as the potato plants grow. Instead of the traditional hoeing into mounds, by backfilling the holes with compost, the square foot gardening method allows the plant to keep pushing up through the compost. This results in a much larger plant stem underneath the compost and an ultimate harvest of many more potatoes.
Step 5: Build a High-Rise for Potatoes
As the backfilling reaches the top of the square foot section, either quit filling with compost and let the potatoes continue to mature, or build a high-rise, bottomless box that’s roughly 12 inches by 12 inches. Be sure that it fits within the square. Then, keep adding compost until the plant reaches the top (just as before). Bartholomew, the person who developed the square foot gardening concept, likes to use 1 by 4 lumber to have the first 6 inches for the potato to grow, plus an additional 4 inches. It certainly isn’t necessary to build a box on top of the square, but some square foot gardening experts like to try this technique for some potato varieties.
Step 6: Plant Different Kinds of Potatoes
Try experimenting with different kinds of potatoes in various parts of the raised garden. Square foot gardening allows such flexibility.
When it’s Time to Harvest
When the plant’s leaves shrivel and turn brown, that’s a signal that the potatoes are ready to harvest. Dig them up and enjoy the satisfying results. Remember that smaller potatoes can be dug up midway through the growing season – or just allow them to grow to maturity.