9 Step Plum Tree Festooning Routine with Victoria on St Julien A Rootstock

St Julien A is a semi-vigorous rootstock, and a Victoria plum on it will settle at about 3 to 4 metres if it is left unpruned. At that height, festooning is still practical and worth doing. Much taller growth puts the work on a ladder, while a smaller rootstock such as Pixy leaves a tree where little bending may be needed. Victoria is partially self-fertile and crops heavily, and when its shoots are pulled toward the horizontal they tend to form more flower buds than shoots left growing straight upward.

These steps assume a two or three year old feathered maiden that has already been planted, staked, and grown through its first full season.

Steps 1 and 2: check the tree, then choose the season

Festooning depends on a simple response in the shoot. Wood held close to horizontal slows its leafy extension and puts more energy into fruit bud formation. A very vigorous rootstock can push back hard against that training, while a strongly dwarfing rootstock usually needs only light shaping. St Julien A sits between those extremes, which is why UK fruit nurseries, including Blackmoor and Keepers, commonly list Victoria on it as a default garden combination.

Find the graft union before you touch a lateral. On a containerised St Julien A tree, it is usually a swollen kink near the base, around 15 to 25 cm above soil level. Growth from below that point belongs to the rootstock, not Victoria. If such a shoot is tied down, it is being encouraged into a sucker that may keep returning for years, so rub it off cleanly at its point of origin.

Next, identify the central leader and the four to six strongest laterals coming from it. Those side shoots are the candidates for bending. Leave anything thinner than a pencil for another season, because it will not hold a useful arch.

Do the main work in late summer. Plums and other Prunus are pruned and shaped from late spring to late summer, never during dormancy, because winter wounds invite silver leaf, the Chondrostereum purpureum fungus that the Royal Horticultural Society identifies as the main reason stone fruit work is kept to warm months.

Festooning mostly uses ties, although an occasional shoot may need removing, and sap-filled wood bends more cleanly. July or August is the useful window, once the current season’s growth has reached 40 cm or more and before it has fully lignified. A lateral that would take a smooth curve in mid-August may crack at the base if the same bend is delayed until October.

If a whole lateral has to come out with Felco secateurs, remove it during this same warm-season window so the wound can seal before autumn damp arrives.

Steps 3 to 5: make the arch without damaging the framework

Take one strong upright lateral and pull it down slowly. Watch the base of the shoot, since that is where a split begins, and let the tip matter less than the point where the wood leaves the leader. The bend should become a continuous curve. If steady resistance changes into a sudden give, stop at once, because the fibres are starting to part. A partial split heals badly on Victoria and gives silver leaf an entry point.

The finished arch should leave the shoot tip pointing roughly at the ground, lower than the place where the shoot grew from the leader. The high point of the curve is where the response matters most. Buds along the upper side of that arch are the ones encouraged into flower clusters the following spring.

Tie with soft jute twine or a strip of old cloth. Wire and nylon line cut into bark as the shoot thickens, so keep them off the tree. Loop the tie around the shoot tip and anchor it to a lower branch, the stake, or a peg pushed into the soil. The loop should hold the arch firmly without biting into the bark. A thumb should still slide under it.

Move around the tree and space the arches evenly. Do not let one cross over another, because crossing shoots rub in wind and make bark wounds. On a three year old Victoria, six to eight festooned laterals is a sensible upper limit. More than that lets the centre shade itself.

Leave the central leader upright. It carries the framework and helps keep the tree in the 3 to 4 metre height band that St Julien A supports. If the leader is pulled over, the tiered structure collapses and the tree loses much of the shape that makes it productive and pickable.

Step 6: feed the fruiting wood

A heavily cropping, festooned plum draws hard on nitrogen and potassium. Plums are not acid-loving plants and want a near-neutral soil, around pH 6.5 to 7, so an ericaceous compost or ericaceous feeding routine is misplaced here. Acidifying the root zone can lock up the calcium that stone fruit needs for the stone itself, which leaves that type of feed for blueberries and rhododendrons.

Apply a balanced fruit feed such as sulphate of potash in late winter, using the rate on the pack. Add garden compost or well-rotted manure as a 5 cm mulch across the root area, keeping it clear of the trunk. Potash supports flower bud quality on the trained arches, while high-nitrogen feeds should stop once the arches are set because nitrogen drives the upright leafy growth that the bending was meant to reduce.

Steps 7 to 9: keep uprights down, remove ties, thin hard

A bent shoot often reacts by throwing vertical water shoots from the top of the arch, sometimes within the same season. If they are left, they restore the upward vigour that the arch was meant to slow.

Work through the tree again in the late-summer window. Pinch those vertical shoots back to four or five leaves, or remove the strongest one outright with Felco secateurs if the arch already has enough wood. Once the initial bend has been made, the annual job is checking the top of each arch and shortening vigorous vertical growth.

Each July, walk the tree and shorten every strong upright that has appeared along an arch. The arches themselves need no further tying once the wood has lignified into shape after the second season.

Leave the twine in place through one full winter and the following spring. By the second late summer, the bend should be set into the lignified wood. Cut the ties off then, and check every loop for constriction before removing it.

Any tie that has started to cut into bark has made a groove, and that groove is both a weak point and a disease entry. Inspect each anchor before cutting it free. If a shoot springs upright as soon as the twine comes off, it was released too soon and needs tying for another season.

Thin the crop after the natural June drop. Festooning can work almost too well on Victoria, which already over-sets and is prone to biennial bearing, with a heavy crop followed by a sparse one. The arches concentrate flower buds, and a wet August can leave them carrying more fruit than the branch can support. Thin young fruitlets in June to roughly one plum every 5 to 8 cm along each arch. Removing healthy fruit feels severe, yet the remaining plums size up properly and the tree is more likely to crop again the following year instead of resting.

The unresolved tension is built into the trained branch itself: the better the arch flowers, the harder the crop has to be reduced.