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Citrus x paradisi
Growing calendar
Typical timing for central Japan (Kanto region). Shift it for your own climate, and record your actual dates.
Guides
- Planting a Grapefruit Tree: Heat, Space and the Pot Question
- Pruning a Grapefruit Tree: Building a Frame Strong Enough to Hold the Crop
- Grapefruit Tree Care: Watering, Feeding and Keeping Sugar Coming
- Grapefruit Year-Round Care Schedule: What to Do in Each Season
- Grapefruit Pests and Problems: What Goes Wrong and What to Do
- When Is a Grapefruit Ripe? Testing, Picking and Leaving It Hanging
Common problems
Start from what you can see on the plant.
Pests and diseases (113)
Problems recorded for this plant, most serious first.
Powdery Mildew
Disease
White patches appear scattered on the upper leaf surface at first, then the whole leaf is coated in a white powder. Leaves later yellow, brown and die back, and reduced photosynthesis cuts growth and yield.
Late Blight
Disease
Dark green water-soaked lesions appear on the leaves and expand quickly into brown dead tissue. White mold forms on the underside and at the lesion edge, and dark brown lesions spread to stems and fruit.
Bacterial Canker
Disease
Leaf margins scorch and die back, and splitting the stem reveals browned vascular tissue. Scabby, bird's-eye lesions form on fruit and shoots.
Sclerotinia Rot
Disease
The crown, stem or head rots in a water-soaked way and is covered in white cottony mycelium. Black sclerotia later form inside and on the surface, and the plant wilts and dies.
Black Rot
Disease
V-shaped yellowing spreads inward from the leaf margins and the veins darken into a black network. As it advances the whole plant wilts and dies.
Black Spot
Disease
On roses, dark brown lesions with radiating edges form on the leaves, which yellow around them and drop. On pear, sooty black lesions appear on leaves, fruit and the calyx of young fruit, deforming the fruit.
Citrus Melanose
Disease
Tiny dark brown specks are scattered over fruit and leaves, sometimes clustering into tear-streaks or a sandpaper texture. Heavy infection makes the rind rough and badly cuts appearance value.
Crown Gall
Disease
Irregular galls form at the crown and on the roots, gradually enlarging and turning woody. They block the flow of water and nutrients, so the plant loses vigor and may die.
Southern Blight
Disease
The stem rots at soil level and white silky mycelium spreads over the crown and the surrounding soil surface. Brown sclerotia the size of rapeseed then form and the plant wilts and dies rapidly.
Sooty Mold
Disease
A thin black sooty mold spreads over the upper leaf surface, shoots and fruit. It does not invade the tissue itself, but it blocks photosynthesis and badly spoils appearance.
Anthracnose
Disease
Light brown to dark brown round lesions with sharp margins form on leaves and fruit, slightly sunken in the center. In wet weather salmon-pink slimy spore masses ooze out on the lesions.
Damping-off
Disease
The stem pinches in at soil level, turning water-soaked to brown and thin, and the seedling topples over. Infection before emergence makes the stand uneven with missing plants.
Root-lesion Nematode
Pest
Elongated blackish brown necrotic lesions form on the root surface and fine roots rot away. Above ground the stand is uneven and plants stay small with pale foliage.
Gray Mold
Disease
Water-soaked brown lesions form on flowers, fruit and leaves, densely covered by a fuzzy gray mold. Fruit rots and drops, and decay continues in storage after harvest.
Bacterial Spot
Disease
Small water-soaked spots appear on the leaves, later turning brown with yellowing around them. Fruit develops water-soaked or scabby spots from which rot spreads.
