Anne Swithinbank’s masterclass on: tree planting Established Betula utilis var. jacquemontii ‘Grayswood Ghost’ (Himalayan birch)
Take care if digging a hole in uncultivated clay soil, as this can cause problems
Q
I’m confused about tree planting. We used to fork well-rotted compost into the planting hole and infill soil with variable results, but now read this is not always a good idea and the same with providing a stake. What is right? Dan Nicklin, Portishead, Somerset
Body image: Alamy. All other photography John Swithinbank / TI Media, unless credited
A
There are few rights or wrongs in gardening but just variable methods depending on soil type, the plant in question, and common sense. Barerooted trees are lifted and sent out while dormant for planting between November and March. Potted trees can technically be planted anytime but they, too, are best set in the ground while dormant. For successful planting, soil texture needs to be right and neither saturated nor frozen. We took delivery of three 2ft (60cm) tall, previously potted grafted birch trees (Betula albosinensis ‘Chinese Garden’). Their pots had been removed
and roots balled in clay soil. Conditions were wet, so we heeled them into the kitchen garden. Digging a planting hole in otherwise uncultivated clay soil can cause problems. The hole acts like a bucket, filling with water, and added organic matter holds it like a sponge to drown roots. For small trees like ours, I slit open the ground using a spade and excavate behind slightly, checking the quality of drainage. Roots were slipped in, and good soil from the kitchen garden added to create a slight mound, keeping the graft at soil level. On lighter soils with good drainage or larger areas of well-cultivated and settled soil, adding organic matter will help hold moisture and nutrients. Beware of hard ‘pans’ or solid layers just under the topsoil. Sprinkling roots with a product containing mycorrhizal fungi will help young trees form beneficial partnerships with them and settle faster.
Anne’s picks
Main right image and inset: Alamy
Firmly planted from a large pot, this multi-stemmed Betula utilis var. jacquemontii is unlikely to need staking but will be protected from deer
Planting tricks for tree success
1
Heel bare-rooted plants into the ground when soil conditions are not right for planting. Dig a trench, lay the roots in and cover with soil to prevent freezing and drying.
2
A young bare-rooted birch has been set in an enlarged slit made in the ground. This helps prevent soil sinkage.
3
In rural gardens where rabbits and deer are a problem, use rabbit guards and for roe deer, a chicken wire fence 5ft (1½m) high.
Best way to stake trees ‘LESS is more’ is the golden rule here, but the trees should not rock in the wind. Knock a short stake in at a 45º angle to secure the trunk low down. Tall, leggy specimens might need supporting along the length of their trunks. Use proper tree ties to hold without rubbing and check regularly. Set stakes on the windward side of the tree, so the trunk is blown away rather than towards the stake.
4
Set stakes on the windward side of the tree
Tease roots out gently but thoroughly when potgrown. Here the white stems are protected by folded polythene and the roots over a wheelbarrow using a hand fork. 8 FEBRUARY 2020 AMATEUR GARDENING
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