Winter fertilizing is mostly about not fertilizing. Most plants are dormant in winter, growing slowly or not at all, and they cannot use fertiliser applied now. A feed given in winter sits unused in cold soil, where it can wash away in winter rain, build up as salts around roots, or push a flush of soft growth in a mild spell that the next frost kills. For the great majority of plants, the right winter fertilizing decision is to do nothing, and to feed the soil instead — with compost, which works slowly through winter without forcing growth — or to wait until spring, when plants can actually use what you give them.
That does not mean winter feeding never happens. There are a few exceptions: plants actively growing in mild zones, winter vegetables under cover, and lawns in warm zones can take a light feed, and soil improvers such as compost and well-rotted manure can be spread on empty beds in winter. This guide explains the exceptions, why the general rule is to wait, and how to use winter to prepare for spring feeding instead of feeding now. If you are unsure about feeding a plant in your area, check your local extension service.
Why plants cannot use fertiliser in winter
Plants take up nutrients when they are actively growing, and most plants are not actively growing in winter. Growth slows as days shorten and temperatures drop, roots take up less water and fewer nutrients, and soil organisms that break down organic fertiliser slow down too. Synthetic fertiliser applied to cold soil is not taken up, so it stays in the soil where rain washes nitrogen away, or it concentrates as salts that damage roots. Organic fertiliser breaks down slowly in cold soil, so it is less harmful, but it is also less useful, since the plant cannot use what is released.
Feeding in a mild winter spell is particularly risky, because it can trick a plant into growth. A warm week in January can push soft shoots on a plant that was fed in winter, and those shoots are killed by the next frost, weakening the plant more than if it had never been fed. This is the same reason our fall fertilizing guide advises against late fall feeding, and the risk is greater in winter, when frosts are harder and more frequent. The plant's own calendar, not the gardener's impatience, should decide when feeding starts, and for most plants that is spring, when growth resumes.
The exceptions: what can be fed in winter
Winter vegetables actively growing in mild zones can take a light feed, since they are growing and can use it. Broccoli, lettuce, kale and other cool-season crops grown through winter in zones 9 and 10, or under cover in cooler zones, can benefit from a light liquid feed while they are growing. Our winter vegetable care guide covers winter vegetables, and our fertilizing vegetables guide explains vegetable feeding generally. Use a light, balanced feed, apply it to damp soil, and stop if growth slows or frosts arrive.
Lawns in warm zones, where grass keeps growing through winter, can take a light winter feed, while lawns in cold zones, where grass is dormant, should not be fed until spring. Our winter lawn care guide covers lawn care through winter. Houseplants should not be fed in winter, since they are growing slowly in low light and feeding pushes weak growth — see our fall houseplant care and fertilizing houseplants guides. Fruit trees, roses, shrubs and perennials should not be fed in winter, since they are dormant and cannot use the feed, and a winter feed can damage them. In zones 11 to 13, where plants keep growing year-round, feeding continues at a low rate through winter, since growth never fully stops — see the zone 11 winter gardening guide for how winter works in frost-free zones.
Feeding the soil in winter
Feeding the soil is different from feeding the plant, and it is the useful winter job. Compost spread on empty beds in winter breaks down slowly, feeds soil organisms, and improves the soil for spring, without forcing growth in any plant, since there is no plant growing in the bed to be forced. Our composting basics guide explains how to make compost, and our winter composting guide covers composting through winter. Well-rotted manure can be spread on empty beds in winter in the same way, but never use fresh manure, which burns plants and can carry pathogens, and never use it on food beds close to harvest.
Leaf mould spread on beds in winter improves soil and protects it, and our leaf mulch guide covers leaves in the garden. Bone meal, a slow-release source of phosphorus, can be worked into the soil when planting bare-root trees and shrubs in winter, since it supports root growth without pushing leafy growth — see our bone meal fertilizer guide. Do not apply lime or other amendments in winter without a soil test, since you may be adding what the soil does not need; our soil pH testing guide explains how to test, and our winter soil preparation guide covers winter soil work.
Planning spring feeding in winter
Winter is the best time to plan spring feeding, since you can do it without the pressure of the growing season. Review the year: which plants grew well, which were pale or weak, and what the soil test said. A soil test taken in fall or winter tells you what the soil actually needs, so spring feeding can be targeted rather than guessed. Plan what each bed needs — compost for most beds, a specific feed for hungry crops such as tomatoes, and nothing for herbs, which often have better flavour in poor soil. Our fertilizing vegetables guide explains feeding through the growing season.
Order fertiliser and soil improvers in winter, so they are ready when spring arrives, and check storage, since fertiliser stored damp can cake and lose effectiveness. Plan a feeding calendar: most plants are fed in spring as growth starts, vegetables are fed lightly and often through the season, and feeding stops in late summer so plants harden off for winter. Note the plan down, so spring feeding follows a plan rather than a guess, and check your local extension service for feeding advice suited to your soil type.
Common winter fertilizing mistakes
The most common mistake is feeding dormant plants, which wastes fertiliser and can damage roots. The second is feeding in a mild spell, which pushes soft growth that frost kills. The third is using a high-nitrogen feed in winter, which is the worst choice of all for dormant plants. The fourth is applying fertiliser to dry or frozen soil, where it cannot be taken up and concentrates as salts. The fifth is feeding houseplants in winter, which pushes weak, leggy growth. The sixth is forgetting that compost counts as feeding too, so a bed that received compost in winter does not need a synthetic feed in spring as well. And the seventh is guessing rather than testing: a soil test costs less than the fertiliser wasted by guessing. When in doubt, do not feed, and check your local extension service.
Frequently asked questions
Should I fertilize in winter?
Usually not. Most plants are dormant and cannot use fertiliser in winter. Feed the soil with compost instead, and wait until spring, when growth resumes, to feed plants.
What can I feed in winter?
Winter vegetables actively growing in mild zones or under cover, and lawns in warm zones where grass keeps growing, can take a light feed. In zones 11 to 13, where plants grow year-round, feeding continues at a low rate.
Can I spread compost in winter?
Yes, compost is ideal for winter. Spread it on empty beds and let worms pull it down, or work it into beds being planted. It feeds the soil slowly without forcing growth.
Should I feed houseplants in winter?
No. Houseplants grow slowly in low light in winter, and feeding pushes weak growth and lets salts build up in the compost. Do not feed again until spring.
When should I start feeding again in spring?
When growth resumes and plants are actively growing, generally in spring as days lengthen and temperatures rise. If you are unsure, check your local extension service.