T he potato ( Solanum tuberosum) is an herbaceous annual that grows up to 100 cm (40 inches) tall. As the potato plant grows, its compound leaves manufacture starch that is transferred to the ends of its underground stems (or stolons). The stems thicken to form a few or as many as 20 tubers close to the soil surface.
The number of tubers that actually reach maturity depends on available moisture and soil nutrients. Tubers may vary in shape and size, and normally weigh up to 300 g (10.5 oz) each. At the end of the growing season, the plant’s leaves and stems die down to the soil level and its new tubers detach from their stolons.
The tubers then serve as a nutrient store that allows the plant to survive the cold and later regrow and reproduce. Each tuber has from two to as many as 10 buds (or “eyes”), arranged in a spiral pattern around its surface. The buds generate shoots that grow into new plants when conditions are again favorable.
How tall should my potato plants be?
Your Potato Plants Are Mature & Ready For Harvest – When a potato plant reaches the end of its life cycle, the part of the plant above ground will fall over. Potato plant leaves and shoots will usually turn yellow before they fall over. This still leaves the question of how big potato plants get before they fall over. The answer is, potato plant height really depends on the variety. Potato plants are usually anywhere from 12 to 45 inches tall at maturity, depending on the variety. At maturity, potato height can range from 12 inches ( such as Princess Laratte potato ) to 45 inches tall ( such as the Red Luna potato ). Most potato plants will reach a height of 18 to 24 inches before they start to fall over. Pruning potato plants is usually not necessary unless you are trying to control a pest or disease. Pruning (or “topping”) leggy potato plants will limit their growth. This will reduce their potential to produce a good harvest of tubers. When they fall over, it is a kind of natural indicator of when to harvest the tubers. You can dig up some tubers from beneath your plants to see if they are ready for harvest yet. If you see potato plants turning yellow and falling over around the expected maturity date of the plant, there is nothing to worry about. To calculate the maturity date of your potato plants, it is important to keep track of when you planted them. Potato plants will sometimes grow flowers and even above-ground fruit before maturity! You do not need to remove potato plant fruit – but don’t eat it, since it contains the toxic substance solanine.
How much space do potato plants need?
Spacing & Depth – Potatoes are started from “seed pieces” rather than from true seed. These seed pieces may be small whole potatoes or potatoes that are cut into 1-1/2 to 2 ounce pieces. Plant the pieces soon after cutting. Be sure that there is at least one good “eye” in each seed piece.
Some garden centers and seed suppliers sell “potato eyes” that weigh less than an ounce. These may be too small for optimal production. Small, whole, certified seed potatoes are often the best choice for home gardeners. Plant seed pieces 10 to 12 inches apart and cover in a furrow between 1 and 3 inches deep.
The TOP 5 Potato Growing Misconceptions Dispelled
Space rows 24 to 36 inches apart. The 24 inch spacing is often beneficial because the plants shade the soil and prevent high soil temperatures that inhibit tuber development. “Straw Potatoes” Potatoes grown by a special cultural method in that they are not hilled or cultivated after planting are called “straw potatoes.” The seed pieces and rows should be spaced the same as for conventional cultivation, but the seed pieces are planted at the soil surface.
- Place loose straw 4 to 6 inches deep over the seed pieces and between the rows.
- Potato sprouts should emerge through the straw cover.
- Cultivation should not be necessary.
- Pull any weeds that manage to emerge through the straw cover and add more straw through the season if decomposition starts to thin the layer.
Harvest by carefully removing the straw and picking up the tubers that lie on the soil surface. In addition to weed control, strawing has several other advantages. The straw keeps the soil temperature more uniform and about 10°F cooler, reduces water loss and results in better-shaped tubers.
Should you top potato plants?
When you buy through links on our site, we may earn an affiliate commission. I like to grow potatoes that I can use to cook up some delicious Indian recipes. But I wanted to know if trimming the top of the potato plants would be beneficial or not. You can trim the tops of your potato plants but only when the potato tubers are ready for harvest.
Should you prune potatoes?
Potatoes are hardy plants requiring little pruning as they grow. Once you see small flowers appear on the plants, the potatoes can be prepared for harvesting by trimming the stalks above the ground. The earlier you trim, the smaller the potatoes will be, but small potatoes are sometimes desirable.
Trim the potato stalks just below flowers that appear to remove the flowers. Cut the stem with pruning shears or pinch off the flowers with your fingers. The flowering signifies the plant is mature enough to have potatoes formed underground, but the flowers draw nutrients and energy away from the developing tubers and are unnecessary for plant health. It’s best to remove them. Prune the stalk at the base, where it meets the soil, after the plant has flowered or once the potatoes are the size you want. Cut it with pruning shears to remove the stalk. Discard the greens of the plant or add them to your compost pile. Wait two to three weeks after you trim the stalk before harvesting the potatoes. Whether you trim the plant when the potatoes are small or at the end of the growing season, allowing the tuber to stay in the ground for two to three weeks causes the skin to thicken and harden, helping preserve the potato and keep it fresh for about four to six weeks in most home conditions.