The spring garden
Patience, and then all at once.
Zone 6B · Hunterdon County, NJ
“Never trust an April sky.”
- Last frost
- May 5–11
- Warm-crop rule
- second Sunday in May
- Reference date
- May 8
- Growing season
- 150–170 days
Spring gardening is patience. Every plant in the seed catalog wants to be in the ground on March 15; almost nothing should be. The gardener’s job in spring is knowing what goes out today, what waits until the ground warms, and what has to hold indoors until Mother’s Day — and then, in one long weekend in mid-May, planting all of it at once.
The one rule
The Mother’s Day rule.
Zone 6B’s last frost averages May 5–11. But “average” means half the years are later. A May 15 frost happens roughly once a decade — enough to kill every tomato in the beds if you rushed them out on the 8th.
Warm crops don’t go in the ground until after Mother’s Day.
Tomatoes, peppers, eggplant, basil, cucumbers, squash, melons, beans — all wait. The extra 7–10 days after the calendar last frost catches almost every late cold snap. And warm soil (60°F+) matters more than warm air for the roots to establish.
Crops by cold tolerance
What goes out when.
Spring is a three-wave planting: hardy crops in March, semi-hardy in late April, and everything tender after Mother’s Day. Trying to compress it into one weekend kills half the tender crops; spreading it across the correct windows doubles the season.
Hardy
Goes in the ground as soon as it's workable — March/early April
Cool-loving crops that shrug off frost and actively prefer cold nights. Sow the moment you can crumble a handful of soil. Waiting for warmth wastes six weeks.
- Peas (snap, snow, shelling)
- Spinach
- Radishes
- Lettuce (leaf and butterhead)
- Kale
- Collards
- Chard
- Onion sets & leek starts
- Potatoes (seed)
- Beets
- Carrots
- Turnips
- Broccoli, cabbage, cauliflower transplants
- Parsley
Semi-hardy
Late April into early May — tolerates light frost
Won't die from a 30°F night but doesn't love it. Wait until soil warms to 50°F. Row cover on unexpected cold nights buys them peace of mind.
- Corn (early varieties)
- Sweet potato slips (wait for warmth)
- Green beans (bush)
- Cilantro
- Dill
- Beet transplants
- Chinese cabbage
- Bok choy
- Nasturtium
The one week that decides the harvest
Hardening off.
Seedlings that spent February and March under grow lights are not ready for full sun and wind. Skipping the transition burns leaves, stunts growth, and sometimes kills the plant outright. The protocol is seven days — the same seven days for everything, from tomatoes to broccoli:
- Day 1–2
2 hours in shaded, sheltered outdoor spot
Any longer and leaves burn from wind and unfiltered light — even in shade. Bring plants back in each afternoon.
- Day 3–4
4 hours, gradually adding direct morning sun
Introduce sun in short doses. Morning sun is gentler than afternoon.
- Day 5–6
6–8 hours; leave outside overnight if 50°F+
Nights are the real test. If forecast dips below 50°F, bring seedlings back in — they're not ready yet.
- Day 7
Full day + overnight in the location where they'll live
Final acclimation. Water well the morning of transplant to reduce shock.
The season, in order
Sow-by timeline.
Measured in weeks before or after last frost (Reference: May 8). Negative weeks are indoor starts; zero is the last frost itself; positive weeks are direct sow or transplant windows.
Onions & leeks
Indoors · 14w before → 12w before
Start Feb 1–15 under lights. Long germination.
Celery, snapdragons
Indoors · 12w before → 10w before
Mid-to-late February.
Brassicas (broccoli, cabbage, cauliflower)
Indoors · 10w before → 8w before
Start early March. Small stocky seedlings transplant best.
Peppers & eggplant
Indoors · 9w before → 7w before
Early to mid-March on heat mat. Long time to fruit.
Peas & spinach
Direct sow · 6w before → 4w before
As soon as soil is workable in late March. Cold-loving.
Tomatoes
Indoors · 6w before → 4w before
Late March. Ready to transplant after Mother's Day.
Lettuce, chard, radishes
Direct sow · 4w before → 1w before
Direct sow through April. Succession sow every 2 weeks.
Carrots, beets, turnips
Direct sow · 4w before → 1w after
Direct sow April into May.
Brassica transplants
Transplant · 3w before → Last frost
Harden off 7 days before transplant. Cool soil is fine.
Potatoes
Direct sow · 2w before → Last frost
Plant seed pieces in trenches; hill up as they emerge.
Corn (early)
Direct sow · 1w after → 2w after
Wait until soil is 55°F. Sow in blocks for pollination.
Beans (bush & pole)
Direct sow · 1w after → 3w after
Wait for warm soil. Succession sow every 2 weeks.
Cucumbers, squash, melons
Direct sow · 1w after → 3w after
Warm soil is essential. Direct sow after last frost.
Tomatoes, peppers, eggplant
Transplant · 1w after → 3w after
AFTER MOTHER'S DAY. Not before. One cold night ends them.
Basil
Transplant · 2w after → 3w after
Basil is the most cold-sensitive herb. Wait for 50°F+ nights.
The palette
Varieties that earn a spring bed.
Spring performance is variety-specific. Bolt-resistant lettuces beat generic packets by weeks; early tomatoes ripen a full month before the main crop. These are the picks that reliably deliver in Zone 6B.
Pea · 'Sugar Ann' or 'Cascadia'
Snap peas that need no trellis. 60 DTM. Sow late March; harvest late May before the heat comes and turns them starchy.
Pea · 'Green Arrow'
Classic shelling pea, heavy yielder, disease-resistant. The one to grow if you want to freeze peas for winter.
Spinach · 'Space' or 'Tyee'
Slow to bolt, smooth-leaved, easy to wash. Sow late March through April; harvest May–June before summer heat forces it to seed.
Lettuce · 'Buttercrunch' or 'Nancy'
Butterhead lettuces that hold well in cool spring weather. Bolt-resistant compared to leaf lettuces. Best sown in succession every 2 weeks.
Radish · 'Cherry Belle' or 'French Breakfast'
28–30 DTM. The instant-gratification spring crop. Sow every 2 weeks March through May; stop when weather warms — they turn woody in heat.
Tomato · 'Early Girl'
55 DTM from transplant. Reliable first ripening in July, well ahead of the main-season varieties. Not the best-tasting tomato, but the first one you'll eat.
Tomato · 'Sun Gold' (cherry)
One of the sweetest cherry tomatoes ever bred. Prolific, disease-resistant, indeterminate — pick daily July through frost.
Pepper · 'King of the North'
Cold-tolerant sweet bell pepper bred for the Northeast. Sets fruit reliably even in cooler summers. Blocky red fruits by August.
Broccoli · 'Green Magic' or 'Arcadia'
Spring-adapted broccolis that head up before summer heat forces bolt. Start indoors early March, transplant early April.
Cabbage · 'Farao' or 'Copenhagen Market'
Early spring cabbages, 60–70 DTM. Harvest before summer heat splits the heads.
Green bean · 'Provider' (bush)
The most reliable bush bean for NJ. 50 DTM, heavy yields, disease-resistant. Succession sow every 2 weeks late May through July.
Cucumber · 'Marketmore 76'
Classic slicer, disease-resistant, prolific. Direct sow after Mother's Day. One plant feeds a small family; two feeds the neighborhood.
Zucchini · 'Dark Star' or 'Costata Romanesco'
'Dark Star' is the productive workhorse; Costata Romanesco is the flavor-forward Italian heirloom that never gets watery even at squash-bat size.
The rhythm that keeps the harvest coming
Succession sowing.
One big planting produces one big harvest, then nothing. Small plantings every 2–3 weeks give you a steady flow. Start in spring; keep going through the growing season.
Bush beans
Every 2 weeks · May 20 – July 31
Bush beans produce heavily for 3–4 weeks then decline. Succession sowing keeps you in beans from July through October.
Lettuce & leaf greens
Every 2 weeks · March – May, then August – September
Lettuce bolts in summer heat. Pause June–July, resume in August for a fall crop.
Radishes
Every 2 weeks · March – May, then August – October
30-day crop. Pause during hottest weeks (mid-June through July) — heat turns them woody and hot-flavored.
Carrots
Every 3 weeks · April – July
Long germination but reliable. Later plantings mature into fall and can be left in ground under straw through December.
Cucumbers
Every 3 weeks · May 20 – July 15
First plants get exhausted by August. A second sowing in mid-June keeps you in cucumbers into September.
Cilantro
Every 2 weeks · March – May, then August – September
Cilantro bolts fast in heat. Weekly sowings from March through late May, then again in cool fall weather.
The other spring deadline
When spring greens bolt.
The spring greens window closes when summer heat arrives. Lettuce, spinach, cilantro, radishes — all send up flower stalks and turn bitter when nights stay above 60°F. Harvest before they bolt; know when to pull the bed and switch to summer crops.
Lettuce
March – late May
Signs: Center stem elongates, leaves get bitter, plant sends up flower stalk
Swap in: Replace with bush beans, cucumbers, or summer squash
Spinach
Late March – May
Signs: Leaves shrink, pointed shape appears, seed stalk shoots up fast
Swap in: Replace with New Zealand spinach (heat-tolerant) or Malabar spinach
Cilantro
March – May
Signs: Feathery leaves replace flat ones, then white flower umbels
Swap in: Let it flower for beneficial insects; sow again in September for fall crop
Radishes
March – May
Signs: Roots turn woody, tops elongate, flowers form
Swap in: Switch to summer greens or take a break — resume in September
Peas
April – early June
Signs: Vines yellow, pods stop forming, plants collapse
Swap in: Pull vines, add to compost, direct sow bush beans in the same spot
Arugula
March – May
Signs: Leaves get sharply pungent, flowers form quickly
Swap in: Let a few flower for pollinators; sow again in September
What’s hunting the spring garden
Spring pests.
The first pest waves hit in late April and May. Row cover from transplant through mid-June solves most of them without spraying — and it’s the single most effective organic pest tool in the garden.
Flea beetles
Peak: Late April – May
Targets: Brassicas, radishes, eggplant
Tiny black jumping beetles that riddle leaves with pinhole damage. Row cover from transplant prevents them entirely. Sprays don't help much.
Cabbage moth (first wave)
Peak: Late April – May
Targets: Brassicas
The white butterflies you see fluttering low over the beds are laying eggs. Row cover blocks them. Hand-pick eggs weekly if you're not covered.
Asparagus beetle
Peak: May
Targets: Asparagus spears
Metallic blue-black beetles that chew emerging spears. Hand-pick daily during harvest weeks. Neem for heavier infestations.
Colorado potato beetle
Peak: Late May
Targets: Potatoes, eggplant
Yellow-and-black striped beetles. Hand-pick and crush eggs (bright orange clusters on leaf undersides). Spinosad if population overwhelms hand-picking.
Cutworms
Peak: April – May
Targets: New transplants
Gray caterpillars that curl around a seedling stem at soil level and sever it overnight. Prevention: cardboard or foil collar around each transplant, 1″ into the soil.
What’s next
Put it into practice.
The framework’s the framework. The monthly almanac is where it lands in real time — what to start indoors this week, what to direct sow, what to harden off next weekend.
Back to the almanac.