Yes, but only if you start indoors and pick a fast variety: Environment and Climate Change Canada’s 1981-2010 climate normals put the average frost-free season at St. John’s at 139 days, running from a mean last spring frost on May 30 to a mean first fall frost on October 17. That’s short for tomatoes, and the word “mean” matters: frost falls later than May 30 in roughly half of all years on record. Start seed indoors this month if your outdoor planting date is still weeks away, and pick a 55- to 60-day variety before you worry about anything else. See Tomato Varieties That Ripen in Time in Newfoundland and Labrador for options that fit this short season.
When to plant Tomatoes in Newfoundland and Labrador
Environment and Climate Change Canada’s 1981-2010 Canadian Climate Normals, measured at the St. John’s A station, put the mean last spring frost at May 30 and the mean first fall frost at October 17, for an average frost-free window of 139 days. That’s the figure to plan around near St. John’s. Further inland, across the interior of the island, or up into Labrador, the frost-free season runs shorter and later, sometimes by several weeks, so treat these dates as a starting point rather than a fixed calendar for the whole province.
The word “mean” matters more than it looks. A mean date is the midpoint of many years of records, which means in roughly half of those years the last frost fell after May 30, not before it. Treat May 30 as the center of a range, not a green light. Tomatoes are killed outright by even a light frost, so setting transplants outside right on the mean date is a bet most gardeners lose at least one year in two.
That’s why the varieties suited to this province go out in mid-June rather than right at the mean frost date. Waiting two to three weeks past May 30 buys real insurance against a late frost, at the cost of a slightly shorter growing season, and given how short the season already is, that trade is worth making on purpose rather than by accident. For a fuller breakdown of how to work out your own dates, see Tomato Planting Dates in Newfoundland and Labrador: Counting Back From Your Frost Window.
Working backward from a mid-June transplant
Seed starting has to happen indoors. There is no realistic way to direct-sow tomatoes here and still get a harvest. Count back six to eight weeks from a mid-June transplant date and you land on starting seed indoors somewhere between the middle and the end of April. Use a heat mat if the house runs cool: tomato seed germinates slowly and unevenly below about 70°F, and a slow start eats into the margin you’re trying to build.
Once seedlings have their first true leaves, pot them up into larger containers so the roots don’t stall, and keep them under strong light. A sunny windowsill in Newfoundland in April usually isn’t bright enough on its own, so seedlings stretch and go leggy. A shop light or grow light run for 14 to 16 hours a day produces sturdier plants.
Harden off over seven to ten days before transplanting, moving plants outside for a few hours at a time, starting in shade and working up to full sun and a full day outdoors. Skipping this step is the single most common way gardeners lose a tray of otherwise healthy seedlings to wind and sunscald in the first week outside. Watch the extended forecast around your planting date, and if a late frost is still expected after you’ve hardened off, keep transplants in a cold frame or under row cover rather than risk the coin flip.
Soil and site preparation
Tomatoes want the sunniest spot on the property, a minimum of six to eight hours of direct sun, and in a short, often cloudy coastal season that number is not negotiable. A wall or fence that reflects heat and blocks the prevailing wind helps more here than it would further south, since wind chill slows tomato growth even when the air temperature itself is tolerable.
Much of Newfoundland’s garden soil is thin, rocky, or heavy with clay, and tomatoes do not tolerate wet feet. Raised beds or large containers solve both problems at once: they warm up faster in spring than ground-level soil, and they drain away the excess rain that pools in low-lying clay. If you’re planting in the ground, work in several inches of compost or well-rotted manure the previous fall, or at least a few weeks before transplanting, so it has time to break down rather than tying up nitrogen right when the plants need it most.
Check drainage before committing a bed to tomatoes: dig a hole about a foot deep, fill it with water, and see how long it takes to drain. Standing water after a few hours means the site needs raised beds or a drainage fix, not just better luck with the weather this particular year.
Space indeterminate varieties two to three feet apart. Determinate and bush types can go slightly closer, around 18 to 24 inches. Crowding is a bigger risk here than in a longer, drier season: tight spacing traps moisture around the leaves, and slower air movement in a damp coastal climate gives fungal disease more time to take hold before the season even finishes. Give plants the full spacing even if the bed looks sparse in June. They will fill in.
Varieties that suit Newfoundland and Labrador
Two traits decide whether a tomato variety is worth growing here: how many days it needs from transplant to first ripe fruit, and whether it holds up in cool, damp weather without demanding heat this province doesn’t reliably provide. Days to maturity is the number to check before anything else, since a variety bred for a long, hot Midwestern summer will still be green when frost arrives on the Avalon Peninsula.
Catalogue days-to-maturity figures are counted from the transplant date, not from seed, and they shift by a week or two depending on how warm and sunny the actual season turns out to be. Treat every figure below as a guide, not a guarantee.
Fast cherry and salad types are the safest bet for a first-time grower here. Sakura and Edox both list 55 days to maturity and carry resistance to Fusarium wilt and tomato mosaic virus, useful insurance in a damp climate where soil-borne disease can linger between seasons. Sun Gold, at 57 days, is an orange cherry tomato bred more for flavor than for disease resistance, and it’s worth the space for that reason alone. Juliet and Supersweet 100, at 60 days, both extend the harvest with heavy, small-fruited clusters.
Slicing and paste types need more patience and more of the season’s margin. Cherokee Purple and Big Beef Plus, both around 72 days, and San Marzano II and Celebrity Plus, at 78 days, are the longest-season varieties worth attempting, and they only work if the transplant goes out on schedule with no delays. Amalfi, a determinate paste tomato at 68 days with resistance to early and late blight, splits the difference between a fast cherry tomato and a full-season slicer.
| Variety | Days to maturity | Type | Notable resistance | Est. margin before mean fall frost* |
|---|---|---|---|---|
| Sakura | 55 | Indeterminate | Nematodes, ToMV, Fusarium 1/2 | 71 days |
| Edox | 55 | Indeterminate | Nematodes, ToMV, Fusarium 1/2 | 71 days |
| Valentine | 55 | Indeterminate | Early blight (intermediate) | 71 days |
| Glacier | 55 | Determinate | None listed | 71 days |
| Sun Gold | 57 | Indeterminate | ToMV, Fusarium 1 | 69 days |
| Supersweet 100 | 60 | Indeterminate | Verticillium, Fusarium 1 | 66 days |
| Juliet | 60 | Indeterminate | Late/early blight (intermediate) | 66 days |
| Amalfi | 68 | Determinate | Nematodes, late/early blight | 58 days |
| Cherokee Purple | 72 | Indeterminate | None listed | 54 days |
| Big Beef Plus | 72 | Indeterminate | Nematodes, gray leaf spot, ToMV | 54 days |
| Granadero | 75 | Indeterminate | Nematodes, Verticillium, ToMV | 51 days |
| Tiren | 75 | Indeterminate | Verticillium, ToMV, Fusarium 1 | 51 days |
| San Marzano II | 78 | Indeterminate | None listed | 48 days |
| Celebrity Plus | 78 | Determinate | Nematodes, gray leaf spot, ToMV | 48 days |
*Margin figures assume a mid-June transplant and are calculated against the mean first fall frost of October 17 from Environment and Climate Change Canada’s St. John’s A normals. A garden further from the coast or at higher elevation should treat every margin figure as smaller than shown.
What to plant alongside
Basil is the classic tomato companion, and while the folklore claim that it repels hornworms and improves tomato flavor has little solid research behind it, basil takes up little space, shares the same watering and feeding needs, and draws in pollinators when it flowers. That combination of low competition and real benefit is what makes a companion worth planting, rather than the myth attached to it.
Marigolds have better evidence behind them: certain types suppress root-knot nematodes in the soil around their roots, which matters if you’re growing a variety without built-in nematode resistance. Borage and other open, nectar-rich flowers draw pollinators to the bed, which helps fruit set on a crop that Newfoundland’s cooler, breezier weather already makes harder to pollinate reliably. Interplant flowers rather than relying on the tomatoes alone to attract bees, especially early in the season before other garden plants are blooming.
Keep tomatoes well away from potatoes. Both are in the nightshade family and both host the same blight organisms, so planting them side by side, or even in the same bed in consecutive years, gives any blight that shows up on one crop a direct path to the other. Fennel is worth keeping out of the vegetable garden entirely: it produces compounds that measurably slow the growth of many neighboring plants, tomatoes included, and it’s one of the few companion planting warnings that actually holds up under study.
Corn shares a major pest with tomatoes. The same caterpillar causes corn earworm damage in one crop and tomato fruitworm damage in the other, so growing them in adjacent rows gives the pest an easy hop between hosts once it finishes with one. None of this means a mixed bed will fail. It means choosing neighbors for a reason, not a rhyme.
Watering, feeding and support
Water deeply and infrequently rather than a little every day. Tomatoes root deep when the topsoil is allowed to dry between waterings, and that deeper root system copes far better with an odd dry stretch than a plant that’s been kept shallow and constantly damp. Aim the water at the soil, not the foliage, since wet leaves sitting in cool coastal air are exactly the conditions that let fungal disease take hold.
Mulch the bed once the soil has genuinely warmed, straw or shredded leaves both work, to hold moisture and keep soil from splashing onto the lower leaves every time it rains. Skip the mulch until the soil is genuinely warm: mulching too early insulates cold soil and slows root growth right when you need the plant moving fast.
Feed lightly and consistently rather than in one heavy dose. A balanced fertilizer at transplanting gets the plant established, then switch to something lower in nitrogen and higher in potassium once flowering starts. Too much nitrogen produces a lush, dark green plant with plenty of leaves and very little fruit, which is the last thing you want in a season this tight on time.
Staking, caging and pruning
Indeterminate varieties, which is most of the list above, keep growing and setting fruit until frost stops them, and they need a stake or a sturdy cage from the day they go in the ground. Determinate types like Glacier, Amalfi and Celebrity Plus grow to a set size, set most of their fruit in a shorter window, and can usually get by with a lighter cage.
Prune suckers, the small shoots that appear in the joint between the main stem and each leaf branch, on indeterminate plants at least once a week. Removing them channels the plant’s energy into fruit that’s already set rather than into more foliage, and in a season measured in weeks rather than months, that redirection is worth the ten minutes a week it takes. Stop pruning and pinch off the growing tip of each main stem about a month before your expected first fall frost, so the plant puts its remaining energy into ripening the fruit it already has instead of starting new flower trusses that have no chance of maturing.
Common problems
Most tomato problems in a cool, damp climate trace back to one of two things: fungal disease finding a foothold in slow-drying foliage, or fruit-set trouble caused by weather that’s cooler and breezier than a tomato really wants. Knowing which symptom points to which cause saves a season of guessing.
Blossom end rot
A flat, leathery, dark patch on the bottom of the fruit, while the rest of the tomato looks fine, is blossom end rot. It’s a calcium delivery problem, almost always caused by uneven watering rather than a genuine lack of calcium in the soil. Fix the watering rhythm before you reach for a calcium spray. Keeping soil evenly moist solves most cases within a couple of weeks as new fruit sets.
Fruit cracking
Rings or splits in the skin, usually near the stem, happen when a dry spell is followed by heavy rain or a big drink of water, and the fruit’s flesh grows faster than its skin can stretch. Mulching to keep soil moisture more even, and picking fruit as soon as it’s ripe rather than leaving it on the vine, both cut down on cracking.
Leaf curl
Leaves that roll upward into a narrow tube, without discoloration, are usually reacting to heat, wind, or a recent bout of hard pruning rather than to disease, and the plant generally grows out of it within a week or two. Curling combined with yellowing or mottling is a different problem and points toward virus or aphid feeding instead.
Wilt diseases
Lower leaves that yellow, brown, and wilt from the base upward, especially if it happens on one side of the plant first, point to a soil-borne wilt such as Fusarium or Verticillium. There’s no cure once a plant is infected. Pull and discard infected plants rather than composting them, and next year choose a variety bred with resistance, several on the table above carry it built in.
Poor fruit set
Flowers that form and then drop without swelling into fruit are usually a pollination problem rather than a plant health problem. Tomato flowers rely on wind and vibration, or bees, to shake pollen loose, and a run of cool, still, damp days interrupts that. Gently shaking the flowering trusses by hand every few days during a stretch of poor weather can noticeably improve fruit set.
Slugs and aphids
Slugs leave ragged holes and slime trails on lower leaves and on fruit touching the soil, and they’re worse in exactly the damp, mulched conditions that also suit tomatoes, so check under mulch regularly. Aphids cluster on stems and the undersides of leaves and are usually knocked back with a strong spray of water or insecticidal soap before their numbers build up enough to spread virus between plants.
Ripening before the frost comes back
Start from the frost-free total: Environment and Climate Change Canada’s St. John’s A normals put the average frost-free season at 139 days, running from a mean last frost of May 30 to a mean first fall frost of October 17. Tomatoes go out mid-June rather than at the last frost date, though, which trims the usable growing window to roughly 120 to 125 days between transplant and the mean fall frost.
Set that number against the days-to-maturity figures in the table above and the picture is clear. A 55-day variety like Sakura, Edox or Glacier needs 55 days to first ripe fruit and leaves roughly 71 days of margin before the mean frost, plenty of room even in a cooler-than-average year. A 78-day variety like San Marzano II or Celebrity Plus leaves only about 48 days of margin. That margin is the number to watch, not the days-to-maturity figure alone, because it’s what absorbs a late spring, a cool July, or a frost that arrives ahead of the October 17 mean, which it does in roughly half of all years by definition of a mean.
Buying extra weeks
A few practical steps push the margin further in your favor. Starting seed indoors on the early end of the mid-to-late April window, rather than the late end, gives transplants a head start without changing the outdoor transplant date. Black plastic mulch laid over the bed a couple of weeks before transplanting warms the soil several degrees and gets roots growing faster right from the start. A low tunnel or cold frame over the bed in the first two or three weeks after transplanting, and again in the last few weeks before frost, effectively adds warmer days on both ends of the season without moving the calendar dates themselves.
Gardeners further inland or at higher elevation should run this same arithmetic with their own, later frost dates rather than borrowing the St. John’s figures directly. Growers facing an even shorter window lean even harder on the fastest varieties and season-extending covers, a challenge covered in our Growing Tomatoes in Northwest Territories guide.
Harvest and end of season
Pick tomatoes once they’ve reached full color for the variety, whether that’s the red of Big Beef Plus, the deep dusky pink of Cherokee Purple, or the orange of Sun Gold, rather than waiting for them to soften on the vine. Fruit that’s fully colored but still slightly firm ripens the last little bit off the plant with no loss of flavor, and picking at that stage protects the harvest from the last bad weather of the season.
As October and the mean first fall frost of October 17 approach, watch the overnight forecast rather than the calendar date itself, since frost can and does arrive earlier than the mean in a given year. Pick everything showing any color at all the night a frost is forecast, and consider stripping the plant of full-size green fruit too rather than risk losing it outright.
Ripening green tomatoes indoors
Fruit that’s fully grown but still green will usually ripen indoors over the following weeks, laid out in a single layer somewhere cool and dark, or in a paper bag with a banana or apple, which speeds things along by releasing ethylene gas. Check the layer every few days and pull out anything that’s gone soft or started to rot before it affects its neighbors.
Truly small, immature green fruit is unlikely to ripen well no matter how it’s stored, and is better used for fried green tomatoes, chutney, or relish than left to shrivel on a windowsill waiting for color that isn’t coming. Pull the whole plant by the roots once frost has taken it, rather than leaving spent vines in the bed over winter, since old tomato foliage is one of the more common places for disease spores to overwinter in a home garden.
Local help
For planting dates, soil testing, and pest identification specific to your county, contact Newfoundland and Labrador’s Department of Fisheries, Forestry and Agriculture through its provincial agriculture office. County-level advice matters here more than in most provinces, since conditions on the Avalon Peninsula, in central Newfoundland, and across Labrador vary widely. For other crops suited to the province’s short season, browse our Newfoundland and Labrador guides. Gardeners working with a longer, milder season might compare notes with our guide to growing tomatoes in Quebec.
Common questions
Can I grow tomatoes outdoors in Newfoundland without a greenhouse or tunnel?
Yes, plenty of gardeners in and around St. John’s grow tomatoes outdoors every year, but a fast variety and a sheltered, south-facing spot matter more than they would further south. A greenhouse or tunnel isn’t required, it just widens your margin and opens up slower varieties that would otherwise be too risky.
What happens if I plant tomatoes before the last frost date?
A hard frost kills tomato transplants outright: foliage blackens and collapses within a day, and the plant does not recover. Even a light, brief frost sets growth back badly. Since May 30 is a mean rather than a guaranteed safe date, planting right on it, or before it, means betting on the better half of the historical record.
Is Labrador’s growing season the same as St. John’s?
No, and this page’s dates come from the St. John’s A weather station on the Avalon Peninsula. Labrador and much of inland and western Newfoundland run a shorter, later, cooler season, so a grower there should treat the mid-June transplant guidance here as an earliest case rather than a target, and lean toward the fastest varieties in the table, cold frames, and raised beds even more heavily than a St. John’s gardener would.
Do I need to prune suckers on determinate tomato varieties?
Not the way you would on an indeterminate variety. Determinate types like Glacier, Amalfi and Celebrity Plus are bred to grow to a fixed size and set most of their fruit in one window, and heavy suckering can actually reduce the total harvest by removing the very growth that would have carried fruit.
What do I do with all the green tomatoes left on the vine at frost?
Sort them by size before deciding. Full-size fruit that’s just short of turning color will usually ripen indoors over several weeks laid out somewhere cool and dark. Small, immature fruit rarely ripens well after picking and is better used green, in relish, chutney, or fried green tomatoes, than left waiting for color that isn’t likely to come.