Red potatoes in USDA Zone 13 are a cool-season crop in a zone without a cool season in the usual sense. Winter lows stay above 60°F and frost never arrives, so the planting calendar is set by heat, not by frost: potatoes tuber best in mild weather, and the mildest months in the tropics run roughly November through February. Red potatoes are a good choice for Zone 13 because their thin skins and waxy flesh suit salads and roasting, and many red varieties mature a little more willingly in warm soils than the long-season russets — though they still need the cool window to do their best.
Start with certified seed potatoes, not supermarket potatoes, which can carry disease and are often treated to stop sprouting. Cut seed potatoes into pieces with one or two eyes each if they are large, or plant small ones whole.
Zone 13 at a glance
USDA Zone 13 is the hottest zone in the system, with average winter lows above 60°F, covering tropical places such as Puerto Rico, Hawaii and Guam. It is frost-free all year, so there is no last spring frost and no first autumn frost to plan around. Zone 13 has no frost dates to work from, so plant by heat and by the wet and dry seasons instead. These are zone averages, not promises for any one garden — check your local extension service.
| Detail | Zone 13 guidance |
|---|---|
| Winter low | Above 60°F |
| Frost | Frost-free year-round (no last or first frost dates) |
| Days to germination | 14–28 days |
| Days to maturity | 90–120 days |
| Sowing | direct sow |
| Planting window | Coolest months, roughly November–February |
| Harvest | 90–120 days after planting, lifted on a dry day |
| Sun | full sun |
| Soil pH | 5.0–6.0 |
| Spacing | 12 inches |
| Water needs | moderate |
| Cold tolerance | frost-tolerant |
When to plant red potatoes in Zone 13
Plant red potatoes in the coolest months, roughly November through February, aiming for November or December for the most reliable crop. With 90–120 days to maturity, a November planting is ready to dig around February to March, while a February planting matures into rising heat, when tuber formation slows and rot becomes more likely. Stagger two small plantings a few weeks apart to spread the harvest, but stop planting once the hot season sets in — potatoes started in peak heat make leafy tops and few tubers. The planting calendar hub lays out the Zone 13 year, and January in Zone 13 shows the heart of the potato window.
Starting red potatoes in Zone 13
Start red potatoes from certified seed potatoes, cut into pieces with at least one or two eyes each, and let cut faces dry and callus for a day or two before planting so they do not rot in warm soil. Plant eye-up in a trench or shallow hole and cover with loose soil. Sprouts appear in 14–28 days, and once the stems are up, start hilling: draw soil up around the stems as they grow, so the young tubers stay buried and out of the light. Light turns tubers green, and hilling is the simple cure. Repeat the hilling once or twice as the plants grow, keep the bed weeded while the plants are young, and water gently so the seed pieces are not washed bare.
Soil, spacing, sun and water
Red potatoes grow best in full sun, in loose, deep, well-drained soil with a pH of 5.0–6.0. Slightly acidic soil suits potatoes and helps keep some soil diseases down, and a soil test through your local extension service tells you where you stand before planting. Drainage is critical in the tropics: tubers in waterlogged soil rot, so work in well-rotted compost and use raised beds, which shed water after downpours and give tubers space to swell. Space seed pieces 12 inches apart, using the plant spacing calculator to lay the bed out. Red potatoes need moderate water: even moisture while tubers form, since drying out and then soaking causes cracked tubers. Water at the base in the morning, mulch thickly to hold moisture and keep tubers covered, and cut back on water as the tops yellow near harvest.
Companion planting
Good companions for red potatoes include marigolds, basil, onions and lettuce, and marigolds are the classic potato companion. Russet potatoes make the obvious bedfellow — same window, same hilling, different use in the kitchen — and rainbow chard can fill the bed edges while the potato tops are still low.
Pests and problems
The common pests to watch for with red potatoes are aphids, hornworms, flea beetles and whiteflies. Check leaf undersides often and act early: pick hornworms off by hand, wash aphids off with a jet of water, and keep the bed weeded so flea beetles have fewer hiding places. The pest identifier helper can help identify anything unfamiliar. In Zone 13, heat and humidity bring disease pressure that often matters more than insects: wet foliage invites blight, and hot, wet soil rots tubers. Give plants room for air to move, water at the base in the morning, mulch, and rotate out of Solanaceae beds each year. If a plant collapses suddenly, remove it promptly rather than letting problems spread through the row.
Harvest and storage
Harvest red potatoes when the tops yellow and die back, about 90–120 days after planting. Dig with a fork from the edge of the row so you do not spear the tubers, and lift them on a dry day when you can. Red potatoes have thin skins that bruise and tear easily, so handle them gently, let them dry briefly out of strong sun, and brush off loose soil rather than washing them. Cure in a dark, airy place for a week, then store only clean, undamaged tubers in a cool, dark, dry spot. Light turns potatoes green and green potatoes should not be eaten, so keep the store dark. In tropical warmth, stored potatoes sprout quickly, so check them often and plan to use the harvest within a few months. The same gentle handling suits russet potatoes, which cure and store the same way.
Frequently asked questions
When should I plant red potatoes in Zone 13?
In the coolest months, roughly November through February, with November or December the most reliable start. A November planting is ready to dig in about 90–120 days, around February to March.
Can I plant supermarket potatoes in Zone 13?
It is not a good idea. Supermarket potatoes may carry disease and are often treated to stop sprouting.
What soil and spacing do red potatoes need in Zone 13?
Full sun, loose deep soil with a pH of 5.0–6.0, seed pieces 12 inches apart.
Why are my red potato skins tearing?
Thin skins bruise easily. Dig gently with a fork from the edge of the row, do not wash freshly dug tubers, and let them dry briefly before handling them much.