Tree or shrubtree ornamentalStraightforward

Crab apple

Malus sylvestris

A small blossom tree that earns a second job: it flowers over a long season and pollinates almost every eating apple in the neighbourhood, which makes it the standard answer for somebody with one apple tree that will not set fruit and no room for a second.

Position: Full sun or Partial shade
Water: moderate demand
Drainage: Moisture-retentive, Free-draining
Grows to: 400–800 cm × 400–800 cm
Hardiness: H6
Harvest: September to November
Difficulty: Straightforward

August

Nothing to do

No sowing, planting, harvesting or pruning window falls in August.

Coming next month: harvest.

Crab apple’s year

Resolved for United Kingdom (general). Every window is stored against a climate event rather than a date, so a late frost pocket runs later than the band shows. What else August calls for.

Activity	J	F	M	A	M	S	O	N	D
Plant	January.	February.	March.					November.	December.
In flower				April.	May.
Harvest						September.	October.	November.
Prune	January.	February.						November.	December.

Timing that travels

The band above resolves this plant's windows into months for one region. These are the windows themselves, stored against a climate event rather than a date — which is the form that survives being carried to a colder garden, a frost pocket, or next year.

Conditions it needs

Light: Full sun, Partial shade
Frost: Very hardy
Hardiness rating: H6 (RHS)
Grows best at: 8–25 °C
Soil: Loam, Clay, Chalky, Sandy
Soil pH: 5.5–7.5
Drainage: Moisture-retentive, Free-draining
Water needs: moderate
Drought: moderate tolerance
Waterlogging: moderate tolerance
Heat: good tolerance
Wind and exposure: good tolerance

Where these figures come from

LightSourced guidancemoderate confidence: Royal Horticultural Society: Crab apple — position
Checked 2026-08-13
FrostSourced guidancehigh confidence: Royal Horticultural Society: Crab apple — hardiness
Checked 2026-08-13
Hardiness ratingSourced guidancemoderate confidence: Royal Horticultural Society: RHS hardiness ratings
Checked 2026-08-13
Grows best atSourced guidancemoderate confidence: Royal Horticultural Society: Crab apple — temperature
Checked 2026-08-13
SoilSourced guidancemoderate confidence: Royal Horticultural Society: Crab apple — soil
Checked 2026-08-13
Soil pHSourced guidancemoderate confidence: Plant Finder — Missouri Botanical Garden: Malus sylvestris — culture
Checked 2026-08-13
DrainageSourced guidancemoderate confidence: Royal Horticultural Society: Crab apple — soil
Checked 2026-08-13
Water needsHorticultural consensusmoderate confidence: No external citation — see the evidence type above.
Checked 2026-08-13
DroughtHorticultural consensusmoderate confidence: No external citation — see the evidence type above.
Checked 2026-08-13
WaterloggingHorticultural consensusmoderate confidence: No external citation — see the evidence type above.
Checked 2026-08-13
HeatHorticultural consensusmoderate confidence: No external citation — see the evidence type above.
Checked 2026-08-13
Wind and exposureHorticultural consensusmoderate confidence: No external citation — see the evidence type above.
Checked 2026-08-13

On your soil

Computed by comparing this plant's recorded requirements against each soil's recorded characteristics. A recorded horticultural fact overrides the comparison where GrowingHQ holds one.

Soil	Verdict	Why
Heavy clay	Works, with one condition	Crab apple will crop on heavy clay, but one thing has to be dealt with first. It needs ground that drains, and this soil holds water. A plant that stays in the ground through winter with its roots in cold, saturated soil rots — which is what kills most of what fails on heavy ground, rather than the cold.Improve the drainage before planting — a raised bed, or bulky organic matter worked in over several seasons. Do not add sand to clay in small quantities; it makes the problem worse.
Sandy	Prefers this soil	Sandy suits Crab apple as it stands: The pH suits it: it wants 5.5 to 7.5, and this soil is in that range. The free drainage is exactly what it wants. Sandy soil is among the soils it is recorded as suiting.
Chalky and alkaline	Grows well here	Crab apple grows perfectly well on chalky and alkaline without special measures, though it is not the soil it would choose.
Loam	Prefers this soil	Loam suits Crab apple as it stands: The pH suits it: it wants 5.5 to 7.5, and this soil is in that range. The free drainage is exactly what it wants. Loam is among the soils it is recorded as suiting. The soil holds moisture, which saves a great deal of watering.
Silty	Prefers this soil	Silty suits Crab apple as it stands: The pH suits it: it wants 5.5 to 7.5, and this soil is in that range. The free drainage is exactly what it wants. The soil holds moisture, which saves a great deal of watering.
Peaty and acid	Works, with one condition	Crab apple will crop on peaty and acid, but one thing has to be dealt with first. It needs ground that drains, and this soil holds water. A plant that stays in the ground through winter with its roots in cold, saturated soil rots — which is what kills most of what fails on heavy ground, rather than the cold.Improve the drainage before planting — a raised bed, or bulky organic matter worked in over several seasons. Do not add sand to clay in small quantities; it makes the problem worse.
Shallow over rock	Prefers this soil	Shallow over rock suits Crab apple as it stands: The free drainage is exactly what it wants. Loam is among the soils it is recorded as suiting.
Made ground and urban soil	Works, with one condition	Crab apple will crop on made ground and urban soil, but one thing has to be dealt with first. It needs ground that drains, and this soil holds water. A plant that stays in the ground through winter with its roots in cold, saturated soil rots — which is what kills most of what fails on heavy ground, rather than the cold.Improve the drainage before planting — a raised bed, or bulky organic matter worked in over several seasons. Do not add sand to clay in small quantities; it makes the problem worse.

Not sure which you have? Four hand tests will settle it.

Space and spacing

Mature height: 400–800 cm
Mature spread: 400–800 cm
Rooting depth: 100 cm
Spacing: 400–600 cm apart

Where these figures come from

Mature heightHorticultural consensusmoderate confidence: No external citation — see the evidence type above.
Checked 2026-08-13
Mature spreadHorticultural consensusmoderate confidence: No external citation — see the evidence type above.
Checked 2026-08-13
Rooting depthHorticultural consensusmoderate confidence: No external citation — see the evidence type above.
Checked 2026-08-13
SpacingSourced guidancemoderate confidence: Royal Horticultural Society: Crab apple — spacing
Checked 2026-08-13

Measured centre to centre. Plants set closer than this compete for light and water long before they look crowded, and the crowding cannot be undone once they are in.

Habit and ultimate size

What the plant becomes, rather than what it is when you buy it. The gap between the two is where most planting mistakes live.

Foliage: Deciduous
In a container: Workable in a container, with conditions

Where these figures come from

FoliageSourced guidancehigh confidence: Royal Horticultural Society: Malus sylvestris — foliage
Checked 2026-08-13
In a containerHorticultural consensusmoderate confidence: No external citation — see the evidence type above.
Checked 2026-08-13

Growth rate: Moderate — roughly 30–60 cm a year
Ultimate height: 400–800 cm
Ultimate spread: 400–800 cm
Time to reach it: 20–25 yearsSourced guidance

Where these figures come from

Growth rateSourced guidancemoderate confidence: Royal Horticultural Society: Malus sylvestris — growth rate
Checked 2026-08-13
Ultimate heightSourced guidancemoderate confidence: Royal Horticultural Society: Malus sylvestris — ultimate height
Checked 2026-08-13
Ultimate spreadSourced guidancemoderate confidence: Royal Horticultural Society: Malus sylvestris — ultimate spread
Checked 2026-08-13
Time to reach itSourced guidancelow confidence: Royal Horticultural Society: Malus sylvestris — time to ultimate size
Checked 2026-08-13

Cutting it back. Prune in winter as for an apple, keeping an open centre. Far less critical than on a fruiting tree, because nothing here depends on fruit size or ripening.

source

Horticultural consensusmoderate confidence

No external citation — see the evidence type above.

Checked 2026-08-13

Value to wildlife

Recorded only where the evidence names a resource and the months it is available. Most plants flower; that on its own is not what this section is about.

Nectar: A significant source
Pollen: A significant source
Berries for birds: Useful, among other plants
In flower: Apr, May
In fruit: Sep, Oct, Nov

Where these figures come from

NectarSourced guidancemoderate confidence: Royal Horticultural Society: Malus sylvestris — value to pollinators
Checked 2026-08-13
PollenSourced guidancemoderate confidence: Royal Horticultural Society: Malus sylvestris — value to pollinators
Checked 2026-08-13
Berries for birdsSourced guidancemoderate confidence: Royal Horticultural Society: Malus sylvestris — fruit and birds
Checked 2026-08-13

What keeping this costs

The long flowering season that makes it such a useful apple pollinator is the same thing that makes it valuable to bees. The fruit hangs long after the leaves fall and is taken through the winter, so picking all of it for jelly is a real choice rather than a free one.

Where and how you can grow it

Each way of growing is assessed separately, and “not assessed” is a real answer rather than a gap we have filled in with a guess.

Method	Suitability	What it needs
Open ground	Well suited source Sourced guidancemoderate confidence Royal Horticultural Society: Growing method suitability Checked 2026-08-13
Traditional dug bed	Workable source Sourced guidancemoderate confidence Royal Horticultural Society: Growing method suitability Checked 2026-08-13
Raised bed	Marginal source Sourced guidancemoderate confidence Royal Horticultural Society: Growing method suitability Checked 2026-08-13	A raised bed rarely holds enough soil volume for a tree beyond its first few years.
Container	Marginal source Sourced guidancemoderate confidence Royal Horticultural Society: Growing method suitability Checked 2026-08-13

Growing it

PollinationA crab apple flowers over a longer period than most named eating apples, so a single tree overlaps with a wide range of cultivars and pollinates them. This is why it is the recommended solution for a lone apple tree that flowers well and never fruits, and it takes up far less room than a second orchard tree.
PruningPrune lightly in winter to keep an open centre, in the same way as an apple but with much less urgency — the fruit is not being grown for size or quality, so the thinning and spur pruning an orchard tree gets is unnecessary.
WateringWater a newly planted crab apple thoroughly through its first two or three summers — this is the single thing that decides whether a young tree establishes, and it is where most failures happen. A slow soak of two or three cans once a week in dry weather is far better than a daily splash, which wets only the surface. Keep a metre of clear mulched ground around the trunk and keep grass off it: turf competing at the base sets a young tree back more than almost anything else. An established tree needs nothing.
FeedingA mulch of well-rotted manure or compost in spring, kept clear of the trunk, is all a crab apple in reasonable soil needs. A general-purpose or high-potash feed in spring is worth giving to a young tree on poor ground or to one grown mainly for its fruit. Avoid high-nitrogen feeding: it produces soft growth that is more susceptible to scab and to fireblight, and fewer flowers, and the flowers are the reason the tree is there.

Where this guidance comes from

PollinationSourced guidancehigh confidence: Royal Horticultural Society: Apple pollination
Checked 2026-08-13
PruningSourced guidancemoderate confidence: Royal Horticultural Society: Malus — pruning
Checked 2026-08-13
WateringSourced guidancehigh confidence: Royal Horticultural Society: Malus — cultivation
Checked 2026-08-13
FeedingSourced guidancemoderate confidence: Royal Horticultural Society: Malus — cultivation
Checked 2026-08-13

The bud you cut to becomes the new shoot, and it grows in the direction it points — which is why an outward-facing bud opens the plant up and an inward-facing one crosses the middle.

What goes wrong

Problem	How often	Notes
Apple and pear scab	common source Horticultural consensusmoderate confidence No external citation — see the evidence type above. Checked 2026-08-13	Disfiguring rather than dangerous — and a spring spore source for nearby apples.

Sources for this page

GrowingHQ editorial synthesis · Plant Finder · Royal Horticultural Society

Each figure on this page carries its own citation, under the “where these figures come from” note in its section. Record last reviewed 2026-08-14.