Walnut tree: care, calendar, diseases
Everything to care for a home walnut tree: when to prune, graft, spot diseases, and ensure pollination.
walnut tree care calendar
| Period | Task |
|---|---|
| June | Check the leaves, trunk and young walnuts |
| September | Keep the ground clean while the walnuts are falling |
walnut tree pollination
The walnut tree is generally self-fertile: a single tree is enough to bear fruit, though it yields more with a second tree. Learn more about pollination.
Pruning and grafting the walnut tree
Prune
- Prune as little as possible, and only in late summer (Aug-Sep): in winter or spring the walnut bleeds sap heavily.
- Limit yourself to dead, diseased or poorly placed wood; avoid large wounds.
- Shape the tree while young, then let it grow naturally.
Graft
- Walnut can be grafted (onto common or hybrid walnut), but take is tricky.
- Graft in the warmth, in spring, with healthy well-kept scions.
- Keep the graft union warm and humid to help it knit.
Leaves and husks contain juglone, which hinders other plants; the husk stains lastingly. Harvest when the husk splits.
walnut tree diseases and pests
Aphids likelySmall insects, curled leaves and sticky honeydew point to an aphid attack.…Codling moth (apple, pear or walnut fruit worm)A caterpillar tunnels to the fruit's core: a small entry hole plugged with frass, fruits r…Chlorosis (deficiency, often iron)Leaves yellow between veins that stay green, mainly on young shoots: not a contagious dise…Scale insectsSmall fixed bumps on the bark or stems, sticky honeydew and a black deposit (sooty mould):…Collar rot (Phytophthora)A dark ooze at the base of the trunk and general decline: a soil fungus attacks the collar…Water stress (lack of water)Dry leaf edges, soft foliage in the heat and early leaf drop: the tree is short of water, …Walnut blightBlack greasy spots on leaves and young walnuts, which may drop: a bacterium favoured by a …
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