Grapefruit

Citrus × paradisi

Family Rutaceae

TreeZones 9-11

Botanical illustration of Grapefruit

Tree-ripened grapefruit is a different fruit from the supermarket kind: it hangs from winter into spring, sweetening the entire time, so you harvest at exactly the honeyed stage you like. Growers in the Deep South and desert Southwest know the secret — heat and patience turn sharpness into perfume.

It demands the most heat of any citrus, so it is honestly a zones 9-to-11, long-hot-summer tree — a stately 20 to 30 feet where it belongs, marginal in a northern pot. Self-fertile and bee-friendly. One familiar footnote travels with the fruit, not the tree: grapefruit famously interacts with certain medications. Where summers scorch, plant the classic.

Where to buy grapefruit — 3 nurseries compared

  • Full Sun — needs the most heat of any citrus
  • Moderate water
  • Moderate growth
  • Excellent edible
  • Attracts bees
  • None winter chill
Grapefruit — a print from the Plant Library collection

From the print shop

Growing grapefruit? Hang it.

Our Plant Library collection carries grapefruit — Citrus paradisi, print Nº 216, “Grapefruit.”

526 designsfrom $12.99white or black backgroundmatte poster, unframed

Shop Plant Library botanical prints →

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Will it fruit where you are?

Enter your ZIP — we look up your USDA hardiness zone (2023 map) and check it against what grapefruit actually needs.

Life cyclePerennial zones 9–11, annual elsewhere
Winter chillNone
PollinationSelf-fertile

Grapefruit · Common problems

Common grapefruit problems

Pests, diseases and weather to keep an eye on.

Pests

3 problems on file

Diseases

2 problems on file

Grapefruit · Growing & propagation

Growing grapefruit

Light, water, soil, propagation and the season’s jobs.
What it needsThe details
Light
Full Sun

Needs the most heat of any citrus

Water
Moderate, deep
Soil
Sandy loam, drained · pH 6.0 - 7.0
Fertilizer
Citrus feed Feb-Sep
Pruning
Late Winter

Minimal; remove suckers and deadwood.

Spacing
15-20 ft

How to plant & propagate grapefruit

Propagate
Grafted, or from cuttings/layering

Seed won't come true

Grapefruit · Harvest & keeping

What you get from grapefruit

How long before it bears, how much it gives, how you know it is ready, and how long it keeps once picked.
Botanical illustration of Grapefruit
Years to first harvest
3 to 5 years
Typical yield
60–150 lbs
What you eat
Fruit
How to tell it is ready
Sweetens the longer it hangs

Often best midwinter into spring; heavy for its size

How long it keeps
2-6 weeks refrigerated

Stores on the tree

Grapefruit · Seasonal care & spray guidance

The grapefruit growing playbook

Field-tested instructions for every job grapefruit asks of you, compiled from university extension guidance — in the order the season brings them.

When to spray grapefruit

Dormant season. Oil in late winter.

Growing season. Oil for scale; certified stock in FL/CA/TX.

While it is dormant

winter, before growth starts

2 jobs
FeedingIn February, May and June

Split the year's nitrogen: before bloom, then twice while fruit sizes

Give a mature tree about 1 pound of actual nitrogen a year, roughly 5 pounds of ammonium sulfate, divided into three feedings: the first in January or February just before bloom, the second in May, the third in June. Young trees need far less and ramp up slowly, about a quarter pound of nitrogen in year two, half a pound in year three, three quarters in year four, reaching the full pound by year five. Broadcast it out to the canopy edge and never against the trunk. Citrus sets its whole crop on the spring growth flush, so the nitrogen has to already be in the soil when the tree blooms. Feeding past midsummer pushes leaves at the moment the tree should be pouring sugar into fruit instead.

ProtectionIn winter

Before a hard freeze: wet the ground, mound the bud union, cover the tree

Grapefruit is among the hardier citrus and may survive temperatures as low as 20 F without significant damage, but when a hard freeze is forecast, water the soil a day ahead and keep it bare rather than mulched. Mound soil up the trunk to above the bud union. Cover small trees with blankets, quilts, or burlap, and for extra warmth hang a string of old-style incandescent lights inside the canopy under the cover, keeping the bulbs clear of water. Pick any mature fruit first. Soil kept moist does not radiate as much heat away to the atmosphere overnight, and that effect is much stronger where the ground around the tree is bare. The soil mound is the insurance policy: soil almost never freezes, so even if the whole top is killed the tree can be regenerated from the trunk just above the bud union instead of reverting to rootstock.

As growth begins

early spring

3 jobs
MulchingIn spring

Mulch the root zone but leave a bare foot around the trunk

Spread organic mulch over the root zone out toward the canopy edge, then pull it back so at least a foot of bare soil rings the trunk. Keep that collar clear when you top the mulch up. Foot rot is a soil-borne fungus that needs a persistently damp trunk base to get established. Mulch piled against the bark holds exactly that moisture there, and the infection can seriously debilitate or outright kill the tree.

PruningIn spring

Prune lightly in spring, and rub off rootstock sprouts

In late winter to early spring, as the tree wakes up and starts pushing growth, take out deadwood, crossing branches that rub, and every shoot rising from below the bud union. Rootstock sprouts give themselves away with trifoliate three-part leaves against the scion's single broad leaf, and while they are soft you can rub them off with a thumb instead of cutting. Keep canopy pruning to the minimum the tree actually needs. A mature grapefruit rarely needs canopy pruning to stay productive, and unnecessary cuts only cost you fruit. Rootstock sprouts are the real target: they bear inedible fruit, and left alone they outgrow and eventually replace the variety you paid for.

What to watch forIn March, April, May, June, July, August, September and October

Check every new flush for Asian citrus psyllid

Every couple of weeks through the warm months, go over each round of new leaf growth. Adults are aphid-sized and mottled brown and feed in an unmistakable pose, head down with the tail tipped up in the air. Look for tiny yellow-orange almond-shaped eggs tucked into the folded new leaves, and nymphs trailing curly white waxy tubules. Watch the older leaves too for blotchy yellow mottling that is asymmetric across the midrib, green on one side and yellow on the other, which is huanglongbing. Control ants while you are at it, since they defend psyllids from the wasps and beetles that would otherwise eat them. The psyllid can only breed on tender new flush, so the flush is both its nursery and the window in which it picks up and injects the huanglongbing bacterium. There is no cure for huanglongbing and it kills a tree within about five years, which makes catching the insect the only real defense.

Through summer

the growing season

1 job
SprayingThrough summer

Greasy spot: oil the leaf undersides once the summer flush has expanded

Soon after the major summer flush has pushed and expanded, spray the canopy with horticultural petroleum oil, working for real coverage on the undersides of the leaves. On grapefruit, add a copper fungicide, because grapefruit is among the susceptible varieties where copper is usually required in the spray to control greasy spot rind blotch on the fruit itself. The fungus reproduces by spores on infected and decaying leaves lying on the soil surface, and rain splashes those spores up into the canopy where they germinate and penetrate the stomata on the leaf undersides. The oil works by physically blocking that penetration, so it has to be on the leaf before infection, not after. You will not see the damage for months, then the tree drops its leaves in late winter and the next crop pays for it.

Harvest time

as it ripens, and picking

1 job
HarvestingAt harvest

Taste one fruit at a time, and let the rest hang

Color is only a rough hint and can mislead you, so pick a single fruit and eat it, then wait and try another in a couple of weeks until the flavor is where you want it. Flavor is always the best indicator of ripeness. Grapefruit holds on the tree for months and gets better while it hangs, which is the whole appeal of the crop: a tree you harvest from all winter rather than all at once. Grapefruit sweetens on the tree as its acidity falls through the winter. Duncan, for example, is edible in November but sweetens and is best in February when the acidity is lower (Univ. of Arizona AZ1925). Flavor is the only honest maturity test.

Grapefruit · Calculators & field guides

A little help in the garden.

Calculators for the figures. Field guides for the hands-on work.

Grapefruit · Yearly calendar

The grapefruit year, month by month

What grapefruit asks for, month by month.

Jan

HarvestDecember to May

MonthJanFebMarAprMayJunJulAugSepOctNovDec
Bloom
Prune
Harvest

BloomMarch to May

PruneFebruary to March

HarvestDecember to May

What each band means

  • Bloom — flowers open — pollinators working, frost on blossoms is the danger.
  • Prune — shape it now — cuts heal cleanly and structure is visible.
  • Harvest — picking time — check ripeness every few days.

These are the species' typical months — expect them a few weeks earlier in warm zones and later in cold ones. Watch the plant, not just the calendar.

Grapefruit · Ecology & uses

Ecology & uses

What it does for the garden, and what it is grown for.
Botanical illustration of Grapefruit

Citrus × paradisi

Grapefruit in the garden system

  • Canopy layer tree
Attracts
Bees
Habitat
Dry/rocky
Moisture
Facultative / average
Deer
Browsed

Protect young plants

Origin
Introduced

What grapefruit is grown for

! Some parts toxic — see notesGrapefruit interacts with many medications (a real caution for the fruit itself)

Use
Breakfast
Use
Juice
Use
Segments
Edible value
4/5

Harvesting & storing grapefruit

Ripens over a LONG season — hangs on the tree from winter into spring, sweetening the whole time.

Edibility, identification, and traditional-use notes here are general reference — not medical or veterinary advice, and not a claim that any plant treats or prevents anything. Medicinal ratings record how strongly a plant features in herbal tradition, nothing more. Never eat or dose a plant you have not positively identified. More on how to use this library.

Grapefruit · Varieties & cultivars

Best grapefruit varieties & cultivars

There are far more than these — the ones below are the named varieties of grapefruit people actually plant.

Named varieties of grapefruit differ in winter-chill needs, ripening time, hardiness, and whether they set fruit on their own — pick one that fits your climate.

11 varieties

Ruby Red

Also known as Redblush, Ruby, Henninger's Ruby

Self-fertile

Ripens
Nov-May
Zones
9-11
Disease
moderate
Size
standard tree 15-20 ft; dwarf on rootstock

mild sweet-tart, pink flesh, nearly seedless — The easy, forgiving classic red grapefruit: self-fertile, reliable wherever winters stay above the low 20s F. Like all citrus it has no chill requirement.

Where to buy ‘Ruby Red’

Story Thyme Farms may earn a small commission from these links, at no cost to you — it never changes what we recommend.

EtsyBrowse growers↗

Sources & plant identity

Know what you’re growing.
See where the knowledge comes from.

Botanical illustration of Grapefruit

Grapefruit

Citrus × paradisi

The plant, at a glance.

Botanical name
Citrus × paradisi
Plant family
Rutaceae
Growth habit
Tree · Tender Perennial
Origin
Introduced
USDA plant symbol
CIPA3
Invasive risk
Low
Every garden is different.

Hardiness, size and timing vary with your cultivar, soil and climate.

Rooted in research.

University extension research, brought together with hands-on growing experience at Story Thyme Farms.

Explore Grapefruit’s sources18 reference links
for Grapefruit

Research from these sources

University of California, RiversideLSU AgCenterMississippi State UniversityTexas A&M AgriLifeUniversity of California ANRUniversity of FloridaUniversity of ArizonaUniversity of Georgia

Publisher marks identify sources, not sponsorship or endorsement.

Questions

Grapefruit questions, answered straight.

Do I need two grapefruit plants to get fruit?

No — grapefruit is self-fertile, so a single plant will set a crop. A second one usually improves yields, but it isn't required.

Is grapefruit safe for kids and pets?

With care. Grapefruit interacts with many medications (a real caution for the fruit itself) Site it accordingly if children or pets roam the garden. This is general reference, not medical or veterinary advice — call a vet or poison control if something has actually been eaten.

When do you harvest grapefruit?

Ripens over a LONG season — hangs on the tree from winter into spring, sweetening the whole time.

How do you propagate grapefruit?

Grafted, or from cuttings/layering (seed won't come true).

Elsewhere

Where grapefruit sits in the library.

Where grapefruit sits in the library

Cold-hardy citrus9Fruit trees31Self-fertile fruit trees20Fruit trees for zone 921All collections

Grows in the same world

Botanical illustration of Black CherryBlack CherryBotanical illustration of MulberryMulberryBotanical illustration of AvocadoAvocadoBotanical illustration of PersimmonPersimmon