Why Spring Timing Is Everything
The difference between a productive garden season and a mediocre one is often made in March and April, before most people think gardening has started. Seeds started at the right time produce stocky, healthy transplants. Seeds started a week too late go in stressed or behind schedule. Seeds started a week too early get leggy under insufficient light. A spring startup schedule keeps everything on track.
8 Weeks Before Last Frost
Start slow-growing crops indoors: peppers (the slowest — they need a long head start), celery, celeriac, and onions from seed. Check and clean all garden tools. Order seeds if not already done. Repair or build any new raised bed infrastructure before the ground thaws completely.
6 Weeks Before Last Frost
Start tomatoes indoors. This is the most important indoor sowing date for most vegetable gardeners. Too early and they become overgrown before transplant; too late and the season is shortened. 6 weeks gives time to reach 6-8 inches tall with a sturdy stem. Start early brassica transplants: broccoli, cauliflower, cabbage.
4 Weeks Before Last Frost
Direct sow cool-season crops outdoors: peas (tolerate frost), spinach, claytonia, mache, and overwintered onions. Soil should be workable — not frozen or waterlogged. Amend raised beds with compost top-dressing if not done in fall. Start cucumbers and squash indoors (they grow fast and do not need a long head start).
2 Weeks Before Last Frost
Begin hardening off indoor transplants — move them outside for increasing periods each day to acclimate to outdoor conditions. Set out transplants of cold-tolerant crops: lettuce, kale, broccoli, onion transplants. Install drip irrigation before it gets warm and busy. Add mulch to beds to retain moisture and suppress weeds.
After Last Frost
Set out tender transplants: tomatoes, peppers, cucumbers, squash, melons. Direct sow beans, corn, basil, and other heat-requiring crops. By this point, the garden is fully operational and the work shifts to maintenance rather than startup.
Frequently Asked Questions
How do I know my exact last frost date?
Search your zip code at the Old Farmer Almanac frost date tool or NOAA climate data. Your last frost date is the average date — actual last frost varies by year. In practice, most gardeners wait 1-2 weeks past average last frost for warm-season transplants, providing a safety margin against late frost events.
What if I missed the ideal start date for something?
Catch-up is possible for most crops. Tomatoes started 4 weeks before last frost instead of 6 will be smaller transplants but still produce well. Peppers are more challenging — under-started peppers often do not yield well in short-season areas. For most crops, a week or two behind schedule matters less than soil temperature and weather conditions after transplanting.
Should I buy transplants or start from seed?
Starting from seed gives more variety options, lower cost at scale, and greater control over timing and growing conditions. Buying transplants is faster and easier, and makes sense for: crops you need only 1-2 plants of, crops like tomatoes and peppers where you do not want to invest in grow lights, and as a backup when seed starting goes wrong.
How many hours of light do indoor seedlings need?
12-16 hours of direct grow light per day, or a south-facing window with strong winter/spring sun. The most common seed starting failure is insufficient light — seedlings stretch toward light sources and become weak and leggy. LED grow lights kept 2-4 inches above seedlings solve this completely.
Can I direct sow tomatoes and skip transplanting?
In zones 9-10, yes — direct sown tomatoes work in those climates. In zones 5-8 where most gardeners are, no — the season is too short. Tomatoes seeded directly outdoors after last frost would not ripen before fall frost in most of the US and Canada.