Spring is the season the garden wakes up, and it is also the season when the most planting mistakes happen. Plant too early and a late frost kills tender seedlings; plant too late and you lose weeks of growing season. The skill of spring planting is not knowing a magic date — there is not one — but reading your own garden's conditions: the soil temperature, the last-frost average for your area, and whether the plants you are putting out are hardy enough for a cold night. This guide explains what to plant in spring, in what order, and how to time it using frost averages rather than guesswork.
Last frost: use averages and ranges, never exact dates
The last spring frost is the key date for spring planting, but it is an average, not a promise. In mild-winter areas the last frost may fall in late winter; in cold-winter areas it may fall in late spring; in zones 11 to 13 there is effectively no frost at all. The range within a single zone can span several weeks depending on elevation, shelter and how close you are to the coast. Use your local frost average as a guide, and plant tender crops a week or two after the average last frost, not on the day itself, because half of all years have a frost after the average date.
Your local extension service publishes frost averages for your area, and that is the most reliable source — check it rather than relying on a generic calendar. The frost date calculator can help you work out your window from your location. Soil temperature matters as much as air temperature: a seed sown into cold, wet soil rots rather than germinating, so wait until the soil has warmed and dried enough to crumble in your hand. A simple soil thermometer is a cheap and useful tool, and it tells you more than the calendar does.
What to plant first: hardy crops and flowers
The first spring plantings are the hardy ones, which tolerate light frost and cool soil. Peas, broad beans, lettuce, spinach, radishes, carrots and onions can be sown directly outdoors weeks before the last frost, as soon as the soil can be worked. Our growing guides for growing lettuce and growing basil explain the sowing depth and spacing, and the zone pages such as zone 5 lettuce and zone 5 tomatoes give the timing for your zone. Hardy flowers such as sweet peas, calendula, pansies and snapdragons can also be planted early, and they tolerate a light frost once established.
Start these crops in succession: sow a small row every two weeks rather than everything at once, so the harvest is spread out and a single cold night does not wipe out the whole crop. Cover early sowings with fleece or cloches on cold nights, and remove the cover during the day so the plants do not overheat. Water gently after sowing, and mark every row with a label, because seedlings of different crops look alike and it is easy to weed out the wrong plants.
What to plant after the last frost
Tender crops — tomatoes, peppers, aubergines, courgettes, cucumbers, beans and sweetcorn — must wait until the last frost has passed and the soil has warmed. Planting them out early gains nothing: they sit in cold soil, grow slowly, and a single frost kills them. Start them indoors six to eight weeks before the last frost, harden them off over one to two weeks, and plant them out only when night temperatures are reliably above 50 degrees Fahrenheit. Our spring seed starting guide explains how to raise them indoors, and our spring transplanting guide covers the move outdoors.
Tender flowers follow the same rule: dahlias, cosmos, zinnias, marigolds and nasturtiums go out after the last frost. Plant them on a cloudy day or in the evening, water them in well, and protect them with fleece if a cold night is forecast in the first week. Mulch around new plantings to hold moisture and suppress weeds — see our spring mulching guide — but keep mulch away from the stems so it does not rot them.
Hardening off: the step most people skip
Hardening off is the gradual adjustment of indoor-grown seedlings to outdoor conditions, and skipping it is the most common cause of transplant failure. A seedling raised in a warm, still room has thin leaves and soft stems; put it straight outside into wind and sun and it wilts, scorches and may die. Harden seedlings off over seven to fourteen days: put them outside in a sheltered, shady spot for a few hours on the first day, bring them in at night, and increase the time outdoors and the exposure to sun and wind each day. By the end of the period they should be spending the whole day outside and, if nights are mild, the night too.
Water seedlings well before they go out, and do not harden them off on a windy or very cold day. A cold frame or a sheltered porch is ideal for hardening off, because it gives protection while letting the plants feel the temperature and the breeze. Once hardened off, seedlings establish much faster and suffer far less transplant shock. If a seedling is damaged during hardening off, move it back inside for a few days and start again more gradually.
Spring planting for flowers, herbs and fruit
Spring is the main planting season for flowers: sow hardy annuals early, plant tender annuals after the frost, and plant summer-flowering bulbs such as dahlias, gladioli and lilies once the soil has warmed. Divide and replant perennials that have outgrown their space, and plant new perennials so they have a full season to establish before winter. Our spring flower care guide covers the details.
Herbs follow the same split: hardy herbs such as parsley, chives and mint can be planted early, while tender herbs such as basil need warm soil and no frost. Fruit planting in spring means planting bare-root and container-grown fruit bushes and trees while they are still dormant, and planting strawberries as soon as the soil can be worked. Check your local extension service for the best planting times for fruit in your area, because they vary widely with climate.
Frequently asked questions
When should I start planting in spring?
Start hardy crops such as peas, lettuce and radishes as soon as the soil can be worked, weeks before the last frost. Wait until after the last frost for tender crops such as tomatoes and peppers.
What is the last frost date?
It is an average, not an exact date — the average date of the last frost in your area, which varies by several weeks from year to year. Plant tender crops a week or two after the average, and check your local extension service for your area's average.
How do I harden off seedlings?
Put them outside for a few hours a day in a sheltered, shady spot, increasing the time and sun exposure over seven to fourteen days until they spend the whole day outside.
Can I plant tomatoes before the last frost?
No. Tomatoes are killed by frost and grow poorly in cold soil. Start them indoors, harden them off, and plant them out after the last frost when nights are reliably mild.
What should I plant first in spring?
Hardy vegetables such as peas, lettuce, spinach and radishes, hardy flowers such as sweet peas and calendula, and bare-root fruit. If you are unsure, check your local extension service for a planting calendar for your area.