Planting a Buddha's Hand Tree: Pot Size, Mix and a Position With Room for the Fingers

What you are actually planting

Buddha's hand is a fingered form of the citron. The fruit splits into separate lobes as it develops, so instead of a single ball you get a hand of five to twenty finger-like segments, each one a tube of rind wrapped around white pith. There is no juice sac worth the name inside, usually no seeds, and no flesh to speak of. The whole fruit is peel, and the peel is what you are farming.

That changes every planting decision. A lemon can knock about in the wind and still give you juice. A Buddha's hand cannot: a finger that rubs against a stake, a wall or a neighboring branch scars, and the scar is on the crop itself. So you are not simply finding a sunny spot. You are finding a spot where a fruit ten inches (25 cm) across can hang for four to six months without ever touching anything solid.

The second constraint is cold. This is one of the most cold-tender citrus grown. Growth stops below about 55F (13C), leaf edges burn in the high 30s F (3-4C), and a night at 28F (-2C) kills wood outright. Unless your winter minimum genuinely stays above 40F (4C), plant it in a container that comes under cover every winter rather than in open ground.

Do not plant it against a warm wall in the hope of extra heat unless the branch tips will still hang two feet (60 cm) clear of the brickwork. Radiated warmth is worth less than clearance around the fruit.

Choosing the pot: size it for moving, not for growing

You will move this pot twice a year for as long as the tree lives, so the limiting factor is what you can lift or wheel through a doorway, not what the roots would enjoy. A tree that carries a dozen fruit is happy in a container far smaller than most people assume, provided you feed it. Step up one size at a time and stop at the size you can still handle.

Buy the pot with a dolly or castors underneath from the start. A wheeled base costs little and turns the autumn move from a two-person job into a one-person job, which matters because the awkward part of carrying this tree is not the weight but keeping the fruit from swinging into the door frame.

A mix that drains in seconds

Citron roots rot faster than almost any other citrus in a wet pot, and a root problem shows up in the fruit as fingers that shrivel at the tip before they color. Mix roughly half bark-based potting mix, a quarter coarse perlite or pumice, and a quarter coarse grit. Poured water should drain through and out of the base within about ten seconds. If it puddles on the surface for half a minute, add more grit before you plant, not afterwards.

Skip water-retaining gels and skip peat-heavy all-purpose potting mix. Both hold water in the lower third of the pot exactly where the roots are least able to cope with it. Target a slightly acid mix, around pH 6.0 to 6.5, which is where citrus takes up iron properly; alkaline tap water will drift it upward over a couple of seasons, so plan to refresh the top few inches each spring.

Getting it into the pot

Plant high. The single most common way people kill a container citron is by burying the graft union, which invites collar rot and lets the rootstock throw suckers below the soil where you never see them. Do this on a mild day when the tree is in active growth, never during a cold spell.

1. Check the roots before anything else Slide the tree out of its nursery pot and look at the outside of the rootball. Cream-colored firm roots are healthy. Brown, soft or sour-smelling roots mean the plant has already been overwatered; tease those away and cut back to firm tissue before potting.
2. Set the graft union two inches clear Part-fill the pot, sit the rootball on the fill, and adjust until the graft union sits about two inches (5 cm) above the finished soil line. Backfill around the sides only. Never let compost drift up over the union later when you top-dress.
3. Firm with water, not with your hands Pressing the mix down compacts the grit you just added. Instead, backfill loosely and water heavily until it runs from the base, then top up any hollows that appear. Repeat once more the same day.
4. Strip every flower and fruitlet for the first season A young tree that sets fruit before it has filled the pot will carry two fruit and put on no wood. Pinch off flowers as they appear for the whole of the first year. You are buying a bigger crop in year three.
5. Shade it for ten days Stand the newly potted tree in bright shade out of direct midday sun for about ten days while the disturbed roots recover, then move it into full sun over the following week rather than all at once.

Where to stand it, and what to write down

Full sun, at least six hours, with shelter from wind on the side the prevailing weather comes from. Wind is the specific enemy here: it does not just dry the tree, it swings developing fingers against the branch behind them and leaves rub marks that stay on the fruit until you pick it. A corner formed by a fence and a wall, or the lee side of a hedge, is better than an open terrace with more light.

Leave a clear circle around the pot at least as wide as the canopy so you can walk right round without brushing the tree. You will want that access for tying branches up later in the season, and every accidental knock in passing costs you rind quality.

Start a record on the day you plant. Note the pot size and date, the compost mix you used, the graft union height, and where in the garden the tree stands. Next spring, when you are deciding whether to step the pot up and where to put it, those four facts tell you more than any amount of memory. Add the date the tree first flowers in its new pot, because that becomes your reference point for everything that follows.