A cool-season root crop that produces a generous harvest of starchy tubers from seed pieces planted in early spring or late summer.
Solanum tuberosum · also called white potato, Irish potato
Windows are counted from the average date of your last spring frost.
Home-grown potatoes offer varieties unavailable in any supermarket — fingerlings, blue-fleshed, and waxy salad types — and freshly dug tubers have a texture and flavor that stored commercial stock cannot match.
A little history. Potatoes are native to the Andean highlands of South America and were domesticated from wild Solanum species. The edible portion is a stem tuber, not a root — each 'eye' is a node capable of producing a new shoot.
Sow seeds 4 inches (102 mm) deep, and aim for 12 inches (30 cm) between plants once thinned. Keep soil consistently moist but not waterlogged; crusted soil delays emergence — break any surface crust gently with a rake. Seedlings emerge in 14–28 days.
Water deeply once or twice a week; increase frequency during tuber bulking (after flowering begins). Water when the top 2 inches of soil feel dry, or foliage begins to look slightly dull. Aim for about 1–2 inches per week during active growth.
Side-dress (scatter fertilizer along the row and water in) once at planting and again when plants are 6 inches tall. What to use: balanced 5–5-5 organic at planting; switch to a lower-nitrogen, higher-potassium blend once flowering starts.
Hill (mound soil up around the base of the stems) when plants reach 6–8 inches tall and again 2–3 weeks later; this buries more stem for tuber formation and blocks light that would turn tubers green.
It's ready when new potatoes: harvest 2–3 weeks after flowering. Maincrop: wait until foliage yellows and dies back naturally, then wait an additional 2 weeks for skins to set firm. Loosen soil with a fork 12 inches from the stem; lift carefully to avoid spearing tubers. Dig on a dry day and let tubers air-dry on the soil surface for 1–2 hours before storing.
Cure in a dark, humid space at 50–60 °F (10–16 °C) for 10–14 days to toughen skins, then store at 38–45 °F (3–7 °C) in darkness with good airflow. Do not refrigerate — cold converts starch to sugar.
Plant an early variety in spring and a second batch of a storage variety in midsummer for a staggered harvest running from early summer through autumn.
Horseradish
Gardeners have long tucked a horseradish plant at the corners of a potato patch, though no study has shown it moves beetles off the crop. If you try it, sink the root in a bottomless bucket — horseradish runs and is hard to dig out of a potato bed.
Basil
A band of strongly aromatic basil along the row can help hide potato foliage from insects that locate their host by smell, and it often reduces light flea beetle pressure. Expect help at low pest levels, not rescue from a beetle outbreak.
French Marigold
French marigold roots have been shown to reduce root-knot nematodes, but only when the bed is planted thickly with them and the tops are turned into the soil at season's end — a few edge flowers do nothing. They do not deter Colorado potato beetles.
Nasturtium
Aphids often settle on nasturtium stems before they find potato shoot tips, which concentrates them where you can act. Pull and bag the loaded stems rather than leaving them — an untended trap crop simply breeds more aphids.
Green Bean
Beans bank nitrogen in root nodules, but most of it is released only as those roots break down, so the benefit lands on next season's crop in this bed. Their shallow roots also share soil comfortably with deeper-feeding potato stems.
Fennel
Fennel roots release substances that reliably stunt most garden vegetables, potatoes included. Grow it in its own corner or a pot well away from the bed, where its umbrella-shaped flowers still earn their keep by feeding hoverflies and tiny parasitic wasps.
Sunflower
Sunflowers are tall, greedy feeders whose wide root systems and afternoon shade often leave potatoes short of water and light just as tubers are bulking. Keep them to the north side of the garden or in a separate bed.
Watermelon
Digging potatoes means turning over soil right where melon vines and their shallow feeder roots are running, and the sprawling vines make it hard to reach the rows. Keep the two crops in separate beds.
Cantaloupe
Old charts keep melons and potatoes apart. What a gardener can verify is practical: both are hungry crops on the same water, and digging potatoes tears through the melons' wide, shallow feeder roots and the vines running over the row.
Pumpkin
Digging potatoes means turning over soil right where pumpkin vines have rooted at their nodes, tearing them loose mid-season. Both are heavy feeders as well, so they compete hard for water and nutrients in the same ground.
Butternut Squash
Both are hungry crops that compete for water and food in the same top foot of soil, and digging potatoes in late summer means forking through the shallow squash roots and running vines. Keep them in separate beds.
Zucchini
Both are heavy feeders with wide root systems, so side by side they compete for water and nitrogen. Digging potatoes also tears through the shallow surface roots that squash relies on in midsummer.
Artichoke
Harvesting potatoes means forking through soil where an artichoke has already spread thick perennial roots and crown buds, and that disturbance sets the plant back. Keep potatoes in the annual beds you turn over each year.
Buckwheat
Buckwheat's canopy closes in about three weeks and can out-muscle young potato plants for light and moisture, and volunteer seedlings get in the way of hilling and digging. Grow it before potatoes, not alongside them.
Sunflower Choke
Both host white mold, and both feed the same soil-dwelling wireworms that tunnel tubers, so the pressure often builds where they share ground. Digging potatoes also chops the sunflower choke's shallow rhizomes and scatters unwanted regrowth.
Jerusalem Artichoke
Both hosts of verticillium wilt, a soil fungus that clogs stem tissue and yellows the lower leaves. Stacking them builds the fungus in one patch of ground, and stray sunchoke tubers left behind will sprout through the potato rows for years.
Goji Berry
Potatoes carry nightshade-family wilts and blights, and digging tubers next to a goji both spreads that soil and tears the shrub's spreading surface roots. Keep at least one bed between them.
Raspberry
Potatoes host the soil fungus that causes wilt in raspberries, and the spores persist for years in the ground. Do not plant canes where potatoes have grown within the last three years, and keep the two beds well separated.
Yacon
Both crops host root-knot nematodes, and growing them together or in sequence can build the population that leaves knobby galls on yacon tubers. Digging potatoes mid-season also churns soil right where yacon crowns are working.
Mashua
Both crops are hosts for late blight, and cool wet autumn weather is exactly when mashua is still in leaf. Growing them side by side lets spores move straight from one canopy to the other; keep them in separate parts of the garden.
Give the tomato family 3 years away from this spot before any of its relatives return.
The pea and bean family, the onion family or the carrot family thrive in this ground next season.
Potatoes are heavy feeders, but digging them leaves the bed loose and easy to work. Keep the tomato family (tomatoes, peppers, eggplant) out for 3 years. Follow with peas or beans, then onions and garlic, or carrots and parsnips, which enjoy the loosened soil.
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