Spring is when the garden starts eating again. After months of slow winter growth, plants wake up, put out new leaves, and need nutrients to fuel that growth — and the soil, which has been leached by winter rain and used up by last year's plants, often cannot supply them. Spring fertilizing is therefore about replacing what was lost and giving plants a steady supply for the growing season ahead. It is also easy to overdo: a heavy dose of fast-acting fertiliser in early spring produces soft, sappy growth that attracts aphids and is damaged by late frosts. The aim is steady, moderate feeding, matched to what each plant actually needs.
What plants need in spring
Plants need three main nutrients: nitrogen for leafy growth, phosphorus for roots and flowers, and potassium for overall health and disease resistance. In spring, leafy vegetables and lawns need relatively more nitrogen, flowering plants need phosphorus and potassium as buds form, and fruit trees need a balanced feed as they leaf out and flower. A balanced general fertiliser suits most of the garden in spring, while specialist feeds suit particular plants: a high-nitrogen feed for leafy crops, a tomato feed once fruit sets, and an ericaceous feed for acid-loving plants such as blueberries and rhododendrons.
Organic matter is the foundation of spring feeding. A mulch of compost or well-rotted manure, applied in spring, feeds the soil slowly all season and improves its structure at the same time — see our spring composting guide and spring mulching guide. Compost feeds gently and is almost impossible to over-apply, which makes it the safest spring feed for most of the garden. Use the fertiliser calculator to work out how much fertiliser a bed needs, and check your local extension service if you are unsure what your soil needs — a soil test is the only way to know for certain.
When and how to feed in spring
Start feeding when plants start growing, not before. A plant that is still dormant cannot use fertiliser, and the nutrients wash away in spring rain. For most of the garden, that means feeding from early to mid-spring, once new leaves are showing and the soil has warmed. Feed on a calm, mild day, water the soil first if it is dry, and apply fertiliser to moist soil, never to dry soil, because concentrated fertiliser burns dry roots. Water in granular fertiliser after applying it, so it reaches the roots rather than sitting on the surface.
Apply fertiliser at the label rate, or less: more is not better, and excess fertiliser leaches into waterways and damages plants. Spread granular fertiliser evenly around the plant, keeping it away from the stems, and do not pile it against trunks or stems. Liquid feeds are useful for a quick boost to plants that are growing fast, such as vegetables and container plants, but they need repeating every two to three weeks because they wash through the soil quickly. Slow-release fertiliser, applied once in spring, feeds for months and suits shrubs and perennials.
Feeding vegetables, flowers, lawns and fruit
Vegetables are the hungriest plants in the spring garden. Dig compost into beds before planting, then feed leafy crops such as lettuce and spinach with a nitrogen-rich feed, and feed fruiting crops such as tomatoes and peppers once they start flowering. Our growing guides for growing tomatoes and growing lettuce explain the feeding for each crop, and our spring vegetable care guide covers the season in detail. Do not feed root crops such as carrots heavily with nitrogen, because it produces leafy tops and poor roots.
Flowers need a balanced feed in spring as they start growing, and a high-potassium feed as buds form, which encourages flowering rather than leafy growth. Roses benefit from a specialist rose feed in spring and again in early summer. Lawns need a spring feed once they start growing actively — see our spring lawn care guide — and fruit trees and bushes need a balanced feed in spring, applied around the drip line, not against the trunk. Container plants need feeding most of all, because their small volume of compost runs out of nutrients within weeks; feed containers every two weeks from spring onwards.
What not to feed, and common mistakes
Do not feed a plant that is not growing, a plant that has just been planted, or a plant that is sick or stressed — fertiliser does not cure a sick plant and can make it worse. Do not feed newly sown seed or tiny seedlings, which burn easily; wait until they have several true leaves. Do not feed in a dry spell without watering first, and do not apply fertiliser before heavy rain is forecast, because it washes away. Do not feed acid-loving plants with a general fertiliser that contains lime, and do not use fresh manure in spring, because it burns plants and may carry weed seeds — only well-rotted manure is safe.
The most common spring fertilizing mistakes are feeding too early, feeding too much, and feeding the wrong plant. A heavy spring feed that produces soft, sappy growth is an invitation to aphids and to frost damage, and it is worse than a light feed. If you are unsure, feed lightly and watch the plant: pale leaves and slow growth mean it needs more, while scorched leaf edges and excessive soft growth mean it has had too much. Check your local extension service for feeding advice specific to your soil and crops.
Organic feeds for spring: manure, seaweed and compost tea
Beyond compost and bagged fertiliser, spring offers several organic feeds that are worth knowing about. Well-rotted manure is the traditional spring feed for hungry plants such as roses, vegetables and fruit: it adds nutrients, organic matter and biology to the soil, and it improves the soil's structure at the same time. It must be well rotted — dark, crumbly and earth-smelling — because fresh manure burns plants and may carry weed seeds. Apply it as a mulch around plants in spring, keeping it away from the stems, and fork it lightly into beds before planting.
Seaweed is a useful spring feed, especially as a liquid: it contains trace elements and growth hormones that encourage root growth and help plants cope with stress, and it is particularly useful for seedlings and transplants. Apply it as a foliar feed or a soil drench in spring, following the label rate. Compost tea — compost steeped in water and strained — is a gentle liquid feed that adds biology to the soil; our compost tea guide explains how to make it, and our vermicompost guide explains worm compost, which is one of the richest feeds of all and can be used as a top-dressing or a liquid feed in spring. None of these replaces a balanced fertiliser for a hungry crop, but together with compost they build a soil that needs less fertiliser every year.
Frequently asked questions
When should I start fertilizing in spring?
When plants start growing actively and the soil has warmed — usually early to mid-spring. A dormant plant cannot use fertiliser, so wait for new leaves.
How much fertiliser should I use in spring?
The label rate or less. More is not better: excess fertiliser burns plants, leaches away and pollutes waterways. Compost is the safest spring feed and is hard to over-apply.
Should I fertilize vegetables in spring?
Yes. Dig compost into beds before planting, then feed leafy crops with a nitrogen-rich feed and fruiting crops once they flower. Do not over-feed root crops with nitrogen.
Can I fertilize a newly planted plant?
No. Fresh compost and soil contain nutrients, and a new plant's roots are easily burnt. Wait several weeks until the plant is growing, then feed lightly.
What is the best spring fertiliser for the whole garden?
A balanced general fertiliser plus a mulch of compost suits most of the garden. Specialist feeds suit particular plants. If you are unsure what your soil needs, check your local extension service and consider a soil test.