Crop-by-crop guides

First thing to settle, before you buy anything: determinate or indeterminate. Determinate plants grow to a set size, dump most of their fruit in a two to three week window, and then wind down. That's a sauce crop — 'Roma', 'San Marzano', 'Amish Paste' — and it's what you want if the plan is to can twenty quarts on one Saturday. Indeterminate plants keep climbing and setting until frost kills them. 'Cherokee Purple', 'Sungold', 'Brandywine', 'Better Boy'. That's a slicing crop, and it needs a real trellis, not a three-dollar cone cage. Most people buy one and treat it like the other, then wonder why the harvest went strange.

Plant deep. Tomato stems grow roots anywhere they touch soil, which almost nothing else in the garden does. Strip the bottom leaves and bury two thirds of the transplant, or dig a shallow trench and lay the whole thing sideways with just the top four inches bent up above ground. A leggy, sad-looking start that got buried to its neck will outrun a stocky one planted shallow by mid-July, because it built three times the root system while it looked like it was doing nothing.

Blossom end rot is the first panic of the season: black leathery patches on the bottom of the first fruit. It is almost never a calcium shortage in your soil. Your soil has calcium. What it doesn't have is steady moisture, and the plant can't move calcium into fast-growing fruit when the bed swings from bone dry to soaked every four days. Mulch, water on a schedule, and it usually stops on its own by the second or third cluster. Don't buy the calcium spray.

Early blight is the different animal, and it's the one that actually ends seasons. Brown spots with concentric rings, lower leaves first, climbing up the plant through July and August. The spores overwinter in your soil and get splashed up onto the leaves by rain. So: three inches of mulch on the ground the day you plant, strip every leaf off the bottom twelve inches of stem, water at the base and never overhead, and rotate the bed. Wide spacing does more than any spray, because a plant that dries off by nine in the morning doesn't get infected.

Corn is wind pollinated, and here's the detail that explains almost every corn failure: every single kernel on that cob comes from one silk catching one grain of pollen. Six hundred kernels, six hundred silks, six hundred separate pollination events. Pollen drops from the tassel at the top and drifts sideways. A gap-toothed ear is not a soil problem, not a pest problem, and not bad seed. It's pollen that had nowhere to land. Plant in a block — at least four rows by four rows, and short fat blocks beat long skinny ones every time. One row along the fence looks tidy and produces almost nothing.

Corn is a heavy nitrogen feeder, which is exactly why the Three Sisters planting exists and why it's more than a nice story. Beans climb the stalks and fix nitrogen in the soil, squash sprawls across the ground and shades out weeds while its prickly leaves discourage raccoons. If you're growing corn on its own you're taking on that feeding job yourself. Side-dress nitrogen when the plants are knee high, and again when the tassels first show. Skip it and you get short stalks and small ears no matter how good the seed was.

Keep your types apart. Sweet corn crossed by popcorn or field corn goes starchy in that same season's crop, not the next one — the pollen affects the kernel you're about to eat. Same for crossing a supersweet with a standard sugary type. Either separate them by a few hundred feet or stagger sowing so they tassel two weeks apart. Supersweet varieties like 'Honey Select' and 'Mirai' also need warmer soil to germinate than standard types like 'Silver Queen', because their shriveled seed rots easily in cold ground.

Corn earworm is the caterpillar you find in the tip when you shuck. It's cosmetic damage most years — cut the tip off. If it bothers you, a few drops of vegetable oil on the silk about five days after silking is the old organic trick, and it works reasonably well. Raccoons are the bigger threat, and they show up the night before you planned to pick. Electric fence or a dog is the honest answer; nothing else reliably stops them.

Buy certified seed potatoes, not grocery spuds. Grocery potatoes are often treated to suppress sprouting, so you'll wait weeks for nothing. Worse, they're the standard way people bring scab, late blight, and virus into a bed they'll be rotating for the next five years. Certified seed is inspected for exactly that. Cut big seed pieces so each chunk has two or three eyes, then let the cut faces sit out a day or two until they skin over. A wet cut face in cold soil is a rot, not a plant.

Hilling is the whole game, and it works because of one fact: potatoes form on stems above the seed piece, never below it. Every time you mound soil or straw up the stem you are literally adding places for tubers to form. Start when the plants are about eight inches tall, bury half the plant, and repeat every couple of weeks until they flower. Straw hilling is easier on your back and makes harvest a matter of pulling the mulch back. Any tuber that catches sunlight turns green, and that green is solanine — bitter, and not something to eat. Cut it away generously or toss the spud.

There are two harvests in every potato patch. New potatoes come any time after flowering: thin-skinned, waxy, and they don't store at all, so eat them that week. The storage harvest waits until the tops die back completely, and then waits another two weeks in the ground while the skins toughen up. Skin set is what determines whether you're eating potatoes in March. Test it by rubbing a thumb across one — if the skin scuffs off, they need more time.

Cure the storage crop in the dark at 50-60°F with decent humidity for about two weeks. That heals the nicks from your fork and thickens the skin. Then move them cold, dark, and airy: 38-45°F. Never store them near onions or apples — apples give off ethylene, which sprouts potatoes early, and onions and potatoes together shorten both. Varieties matter for storage too: 'Kennebec' and 'Yukon Gold' keep for months, while thin-skinned fingerlings and reds are eating potatoes, not keeping potatoes.

Squash carries separate male and female flowers on the same plant. The female has a tiny fruit already formed behind the bloom; the male sits on a plain skinny stem. Early on a plant often throws only males for a week or two — that's normal, not failure, so don't rip it out. Later, when a small fruit yellows at the tip and shrivels off, that's an unpollinated female. The fix takes thirty seconds: pick a fresh male bloom, peel the petals back, and brush the pollen directly onto the center of the female flower. Do it early morning, before the flowers close for the day.

Squash vine borer is what kills most plants in the eastern half of the country. A clearwing moth that looks like a wasp lays eggs at the base of the stem in early summer, the larva bores in and eats the stem hollow, and one morning a plant that was thriving is lying flat with sawdust-looking frass at the soil line. Once the grub is inside the stem, sprays can't reach it. Prevention is the real answer: wrap the lower six inches of stem in aluminum foil or an old nylon at transplant, mound soil over a few points along the vine so it roots in multiple places, and sow a backup round in late June or early July after the main moth flight is over. Butternut and other Cucurbita moschata types have solid stems that borers largely can't use — if you keep losing plants, switch to 'Waltham Butternut' and 'Tromboncino', which works as a summer squash picked young.

Squash bugs are the other one. Gray-brown shield-shaped adults, and bronze egg clusters laid in neat rows on the undersides of leaves. Scrape the eggs off with duct tape twice a week and you'll break the cycle. Lay a board flat on the soil overnight — the adults gather underneath and you can deal with them all at once in the morning.

Powdery mildew shows up on the leaves every August and it is not the emergency people treat it as. By the time it arrives the plant has usually done its job. Space wide, water at the base, pull the worst leaves, and keep picking. If you want to slow it, plant a resistant variety and give the plants more room than the packet says.

Bush beans grow knee high, set nearly everything inside a two week flush, and then wind down. That's the canning crop: 'Provider', 'Contender', 'Blue Lake Bush'. Pole beans climb six to eight feet, start later, and keep producing until frost as long as you keep them picked — 'Kentucky Wonder', 'Rattlesnake', 'Fortex'. Per square foot of ground, pole beans win by a wide margin because you're farming vertically. If you have any fence, arch, or cattle panel, grow pole.

Beans hate cold wet ground more than almost anything else you'll plant. They want 60°F soil minimum and they're much happier at 65-70°F. Sown into cold May soil, the seed swells, sits, and rots — that's the row of mush people dig up two weeks later. They also fix their own nitrogen through a partnership with rhizobia bacteria in the soil, which means adding nitrogen fertilizer actively hurts you: you'll grow a beautiful leafy plant with very few pods. If beans have never grown in that ground, dust the seed with a cheap inoculant powder at planting. It costs a few dollars and noticeably improves the stand in new beds.

Dry beans are the same plant, just left alone longer. Grow them out, stop watering as the pods fill, and leave everything on the plant until the pods rattle and the whole plant goes tan and brittle. Pull the plants whole, finish drying them under cover for a week or two, then thresh — a pillowcase and your feet works fine. Freeze the shelled beans for three or four days before jarring to kill weevil eggs, then store dry and dark.

Two habits protect a bean patch. Never work or pick the rows while the leaves are wet, because bacterial blight moves down a row on wet foliage and your hands are the vector. And trellis before you plant, not after — putting posts in around established seedlings means stepping on roots you can't see.

Lettuce is a cool-season crop that reads heat and lengthening days as a signal to make seed. When it bolts it throws a tall center stalk, the leaves turn bitter from milky latex, and there is no reversing it. So garden the shoulders: sow early spring, then again in late summer for fall. If you want to push into real summer heat, use a slow-bolting variety — 'Jericho', 'Nevada', 'Muir' are the reliable ones — and throw 30-40% shade cloth over the bed. That combination buys you weeks.

Cut-and-come-again is the technique that changes the math. Instead of growing individual heads, sow a leaf mix thickly and cut across the whole patch with scissors about an inch above the crown. The plants regrow from the center growing point and you get three or four cuts from one sowing over six or eight weeks. Cut lower than that inch and you take the crown with it and nothing comes back. Kale and chard work on the same principle from the outside in: take the outer leaves, always leave the center growing tip and at least five or six leaves on the plant.

Spinach is fussier than the rest and worth understanding separately. It won't germinate well above about 75°F soil — the seed just sits — and it bolts earlier than lettuce does in spring. The best spinach you will ever grow is sown in late summer, grown into fall, and overwintered under a low tunnel. Cold converts starch to sugar in the leaf, and a February spinach leaf from under row cover tastes nothing like the April one from a grocery store.

Two things fix most bitter-lettuce complaints. Water: a bed that dries out goes bitter before it bolts, so keep it evenly moist. And timing: cut in the morning while the leaves are turgid with water, then get them cold immediately. Warm-harvested lettuce wilts within the hour and never fully comes back.

Carrot seed is tiny, sown a quarter inch deep, and slow — fourteen to twenty-one days to germinate. For that entire window the top quarter inch of soil cannot dry out or crust over, and that single fact explains nearly every patchy carrot row in America. Water lightly every day, and lay a board or a piece of damp burlap right on the row to hold moisture. Check under it daily and pull it the moment you see green, or you'll cook the seedlings.

Thin twice, and be ruthless. First pass to about an inch when the tops are two inches high, second pass to two or three inches once you can see which plants are strongest. Unthinned carrots braid around each other and stay the size of your finger all season. Snip the thinnings at the soil line with scissors instead of pulling — pulling disturbs the neighbor's taproot, and a disturbed taproot forks.

Forking is a soil problem, not a seed problem. Rocks, hard clods, compacted layers, and fresh manure all cause a taproot to split and branch. Loosen the bed deep and break it fine before sowing, and skip high-nitrogen amendments entirely — nitrogen grows lush tops and hairy, branched roots. If your ground is heavy clay or stony, grow a short blunt type like 'Danvers' or a Chantenay instead of fighting for long 'Imperator' carrots you'll never get.

Beets and radishes are the forgiving end of this family and worth planting alongside. Radishes germinate in three to five days, so scatter a few in the carrot row as living markers — they mark the row while you wait, break the soil crust as they push up, and get pulled long before the carrots need the space. One thing about beets: each 'seed' is actually a cluster of two to four seeds, so they always come up in clumps and always need thinning, no matter how carefully you spaced them.

Onions bulb on day length, and this trips up more gardeners than anything else in the allium family. Long-day varieties need 14-16 hours of daylight to start forming a bulb — 'Walla Walla', 'Copra', 'Yellow Sweet Spanish' — and they're for growers roughly north of the 36th parallel. Short-day types bulb at 10-12 hours and belong in the South: 'Texas Early Grano', 'Red Creole'. Day-neutral varieties like 'Candy' and 'Superstar' work across the middle of the country. Plant a short-day onion in Minnesota and you'll get a lovely green top and a bulb the size of a marble, and nothing you do to the soil will change that.

Garlic goes in the ground in fall, not spring. Plant cloves pointy end up four to six weeks before the ground freezes, mulch heavy with straw, and then forget about it until spring. Hardneck types — 'Music', 'German Extra Hardy', 'Chesnok Red' — handle hard winters and give you scapes in June. Cut those curling flower stalks off when they make one full loop; the plant redirects that energy into the bulb, and the scapes themselves are excellent food. Softneck types store longer, tolerate mild winters better, and are the ones you can braid.

Harvest cues are specific and worth learning exactly. Pull garlic when roughly the bottom third to half of the leaves have browned but the rest are still green — each green leaf is a wrapper layer around the bulb, and if you wait for the whole plant to die the wrappers rot away and the bulb splits apart in storage. Onions tell you differently: wait until the necks go soft and the tops fall over on their own. Don't bend them over by hand to hurry it; forced tops shorten storage life.

Curing decides everything about how long the harvest lasts. Both crops go somewhere shaded, dry, and airy for two to four weeks, until the necks are papery and the outer skins rustle. A garage with a fan, a covered porch, hanging in a shed — all fine, just out of direct sun. Then trim and store cool and dry. Anything that still has a thick green neck at the end of curing won't keep at all, so pull those aside and eat them first. And keep garlic out of the refrigerator: cold plus damp is the exact signal that tells a clove to sprout.

Peppers are slower than tomatoes at every stage and people underestimate that every spring. Seed wants 80-85°F soil to germinate well, and without a heat mat you'll wait three weeks for spotty sprouting. From sowing to a transplant worth putting outside is 8-10 weeks, so a pepper start goes in the tray before the tomatoes do. Then they sit outside doing visibly nothing for a few weeks, which is normal — roots first, top growth later.

Do not rush them into cold ground. Peppers stall below 55°F soil and a plant that got chilled at transplant stays stunted the whole season even after the weather turns. Wait two weeks past your last frost, or lay black plastic or a dark mulch to push the soil temperature up. If you only remember one thing about peppers: warm soil, late planting, and they'll catch up fast.

Blossom drop is the classic mid-summer panic. Peppers abort flowers when nights stay above about 75°F or days push past 90°F, and again when soil moisture swings. It isn't a disease and there's nothing to spray. Mulch, water evenly, give them afternoon shade in a brutal climate, and set resumes on its own when the heat breaks — often producing heavily in September. Too much nitrogen also produces a lush green plant with almost no fruit, same as tomatoes.

Sweet and hot are the same species and they cross-pollinate, which matters only if you save seed — this year's fruit tastes the way the variety says regardless. Capsaicin lives in the placental tissue along the ribs, not in the seeds themselves. Bell types like 'King of the North' or 'Ace' ripen faster in short seasons than the big blocky supermarket kinds. And every pepper is sweeter and more nutritious at full color: a green bell is just an unripe red one, and leaving fruit to color costs you two to three weeks per pepper but pays in flavor.

Melons want heat and room, and that's the whole planning problem. A standard watermelon vine runs 8-12 feet and shades out everything under it, so budget roughly 25-40 square feet per plant. If you don't have that, grow an icebox type — 'Sugar Baby', 'Blacktail Mountain' — which finishes in 70-80 days on shorter vines and fits a small bed or even a strong trellis with fruit slings. In a short season, that variety choice matters more than anything you do to the soil.

Direct sow once soil hits 70°F, or start indoors three weeks early in larger cells and transplant carefully — melons hate root disturbance and a torn root ball sets them back further than sowing late would have. Black plastic or a dark mulch is close to standard practice in cooler zones: it can add several degrees of soil warmth and pull a marginal crop into ripeness. Feed nitrogen while the vines are running, then ease off once fruit sets so the plant puts sugar into melons instead of leaves.

Cucumber beetles are the real threat, less for the chewing than for the bacterial wilt they carry — an infected vine collapses suddenly with a full-sized melon on it. Row cover from planting until flowering keeps them off during the vulnerable stage, then it has to come off so bees can work. Powdery mildew shows up late; water at the base, space for airflow, and accept some leaf loss in August. Keep the fruit itself up off wet ground on a board, a tile, or a handful of straw.

Ripeness is where most people lose the crop, and watermelon and cantaloupe tell you in completely different ways. Watermelon does not slip from the vine and doesn't smell — check three things together: the curly tendril nearest the fruit stem has dried brown, the ground spot has turned from white to buttery yellow, and the skin has lost its gloss. Thumping is unreliable. Cantaloupe is easier: it slips, meaning the stem separates from the fruit with light thumb pressure, the netting stands out corky, and it smells sweet. Watermelon does not sweeten after picking, so an early cut is a loss you can't undo.