Katy
A Swedish early apple, small, bright red and heavy cropping, widely grown for juice. Hardy and dependable in cool summers.
A cultivar of Apple. Everything on this page is about the cultivar; how to grow the species is on the plant page, and how big the tree gets is on the rootstock page.
Names and origin
- Also sold as
- Katja
- Origin
- Sweden, mid 20th century
Pollination
What this cultivar needs before it will set a crop.
- Self-fertility
- Needs a pollination partner
source
Sourced guidancehigh confidence
- Royal Horticultural Society: Apple pollination
Checked 2026-08-13
- Partner
- A compatible partner is required
source
Sourced guidancehigh confidence
- Royal Horticultural Society: Apple pollination
Checked 2026-08-13
- Flowering group
- 3 on the apple scale
source
Sourced guidancemoderate confidence
- Royal Horticultural Society: Apple pollination groups
Checked 2026-08-13
- Ploidy
- diploid
source
Horticultural consensusmoderate confidence
- NIAB — National Institute of Agricultural Botany: Cultivar ploidy records
Checked 2026-08-13
- Partners needed
- one
Partners for Katy, from the 35 apple cultivars GrowingHQ holds
Computed by the pollination engine from the flowering groups, ploidy and recorded pairings on each record — not a hand-written list. The scope is exactly what the heading says: these are the answers that exist in this catalogue, not the answers that exist.
| Cultivar | Verdict | Why |
|---|---|---|
| Annie Elizabeth | compatible | Both flower at overlapping times (groups 4 and 3) and both produce viable pollen. |
| Arthur Turner | compatible | Both flower at overlapping times (groups 3 and 3) and both produce viable pollen. |
| Ashmead's Kernel | compatible | Both flower at overlapping times (groups 4 and 3) and both produce viable pollen. |
| Bountiful | compatible | Both flower at overlapping times (groups 3 and 3) and both produce viable pollen. |
| Charles Ross | compatible | Both flower at overlapping times (groups 3 and 3) and both produce viable pollen. |
| Cox's Orange Pippin | compatible | Both flower at overlapping times (groups 3 and 3) and both produce viable pollen. |
| Discovery | compatible | Both flower at overlapping times (groups 3 and 3) and both produce viable pollen. |
| Egremont Russet | compatible | Both flower at overlapping times (groups 2 and 3) and both produce viable pollen. |
| Ellison's Orange | compatible | Both flower at overlapping times (groups 4 and 3) and both produce viable pollen. |
| Fiesta | compatible | Both flower at overlapping times (groups 3 and 3) and both produce viable pollen. |
| Gala | compatible | Both flower at overlapping times (groups 4 and 3) and both produce viable pollen. |
| Golden Delicious | compatible | Both flower at overlapping times (groups 4 and 3) and both produce viable pollen. |
| Greensleeves | compatible | Both flower at overlapping times (groups 3 and 3) and both produce viable pollen. |
| Grenadier | compatible | Both flower at overlapping times (groups 3 and 3) and both produce viable pollen. |
| Herefordshire Russet | compatible | Both flower at overlapping times (groups 3 and 3) and both produce viable pollen. |
| Howgate Wonder | compatible | Both flower at overlapping times (groups 3 and 3) and both produce viable pollen. |
| James Grieve | compatible | Both flower at overlapping times (groups 3 and 3) and both produce viable pollen. |
| Kidd's Orange Red | compatible | Both flower at overlapping times (groups 3 and 3) and both produce viable pollen. |
| Laxton's Superb | compatible | Both flower at overlapping times (groups 4 and 3) and both produce viable pollen. |
| Lord Derby | compatible | Both flower at overlapping times (groups 4 and 3) and both produce viable pollen. |
| Lord Lambourne | compatible | Both flower at overlapping times (groups 2 and 3) and both produce viable pollen. |
| Pixie | compatible | Both flower at overlapping times (groups 4 and 3) and both produce viable pollen. |
| Red Falstaff | compatible | Both flower at overlapping times (groups 3 and 3) and both produce viable pollen. |
| Rev. W. Wilks | compatible | Both flower at overlapping times (groups 2 and 3) and both produce viable pollen. |
| Scrumptious | compatible | Both flower at overlapping times (groups 3 and 3) and both produce viable pollen. |
| Spartan | compatible | Both flower at overlapping times (groups 3 and 3) and both produce viable pollen. |
| Sunset | compatible | Both flower at overlapping times (groups 3 and 3) and both produce viable pollen. |
| Worcester Pearmain | compatible | Both flower at overlapping times (groups 3 and 3) and both produce viable pollen. |
The fruit
- Season
- Early
source
Sourced guidancehigh confidence
- Royal Horticultural Society: Apple cultivars — season
Checked 2026-08-13
- Use
- Eating, Juicing
source
Sourced guidancehigh confidence
- Royal Horticultural Society: Apple cultivars — use
Checked 2026-08-13
- Keeping
- Eat within days
source
Sourced guidancehigh confidence
- Royal Horticultural Society: Apple cultivars — storage
Checked 2026-08-13
The plant
- Vigour
- Average vigour
source
Sourced guidancehigh confidence
- Royal Horticultural Society: Apple cultivars — vigour
Checked 2026-08-13
- Habit
- Upright
source
Horticultural consensusmoderate confidence
- Royal Horticultural Society: Apple cultivars — habit
Checked 2026-08-13
- Cropping
- Crops regularly
source
Sourced guidancehigh confidence
- Royal Horticultural Society: Apple cultivars — cropping
Checked 2026-08-13
On each rootstock
The size of the tree comes from the rootstock. What the cultivar contributes is a direction, in words — GrowingHQ does not multiply the range by a vigour factor, because no source supports the multiplier and the resulting number would look far more precise than the inputs are.
| Rootstock | Height | With this cultivar |
|---|---|---|
| M27 | 150–180 cmSourced guidanceDepends on conditionshigh confidenceApplies when: In reasonable soil with normal pruning. On poor dry ground an M27 tree can stall well below this and never fill out.
Checked 2026-08-13 | Katy is of average vigour, so the rootstock's range applies as published. |
| M9 | 200–250 cmSourced guidanceDepends on conditionshigh confidenceApplies when: Varies with soil fertility and with how vigorous the grafted cultivar is.
Checked 2026-08-13 | Katy is of average vigour, so the rootstock's range applies as published. |
| M26 | 250–300 cmsourceSourced guidancehigh confidence
Checked 2026-08-13 | Katy is of average vigour, so the rootstock's range applies as published. |
| MM106 | 350–450 cmSourced guidanceDepends on conditionshigh confidenceApplies when: Kept smaller by pruning, but this is the size it wants to reach.
Checked 2026-08-13 | Katy is of average vigour, so the rootstock's range applies as published. |
| MM111 | 450–550 cmsourceSourced guidancehigh confidence
Checked 2026-08-13 | Katy is of average vigour, so the rootstock's range applies as published. |
| M25 | 550–700 cmsourceSourced guidancehigh confidence
Checked 2026-08-13 | Katy is of average vigour, so the rootstock's range applies as published. |
Full profiles for each of these are on the rootstock page.
Cultivar record reviewed 2026-08-13.