Position – Plant your walnut tree in full sun or a spot that gets at least 6 to 8 hours of sunlight a day. Make sure it has plenty of space as it will grow into a huge tree and will be difficult to transplant, even 1 or 2 years later.
Size – These trees grow to a height of between 30 and 40 metres tall with a canopy spread of 18 metres.
Soil – Walnut trees require well-drained, fertile soil like sandy loam. Clay is not advisable. They require slightly acidic soil so they benefit from a bag of our blueberry mix or half a bag of acid compost. Dig a large hole by breaking up the soil and adding plenty of well-rotted organic matter. A wide hole is better than a very deep one.
Nut trees require fertile soil for good growth. So, before you plant it, add some nutrients to your soil like volcanic rock dust and good quality organic compost. Water the soil thoroughly before planting and be careful not to bend the roots.
Fertiliser – In the second year after planting your tree, add a bag of organic compost to the base of the tree in spring and this will meet the plant’s growing nitrogen demands. Too much nitrogen makes the tree more susceptible to walnut blight.
Mulch – It is important to keep the trees free from weeds. Until they are established, mulch around the tree every 3 to 4 months with well-rotted organic matter or our pine bark around the trunk. Remember not to let the mulch touch the trunk, or it could cause rot and infection.
Pests – Watch out for aphids and caterpillars. Aphids can be sprayed with dishwashing liquid solution or a natural organic pest spray for aphids as well as for caterpillars. Alternatively, just squish and kill them when you see them. There are many other pests that could attack your nut tree. So, if it is not looking healthy, check with a nursery.
Watering – Never use a sprinkler and avoid splashing water onto the leaves as this will promote the development of walnut blight. Water the tree well every second week once established, as they become stressed if over-watered.
Pruning – While the tree is dormant, cut off the dry and dead branches. If any branches are crossing, then remove one. You can also remove new shoots in the middle of the tree to ensure maximum light and air penetration.
Frost – Your walnut tree is frost-tolerant but flowers could get damaged with a late frost.
Harvesting – Walnuts fall from the tree when they are ripe. Be sure to collect them quickly to prevent them from moulding on the ground.