Garden Balsam Care: Stripping Leaves to Show the Flowers, Watering and Staking

The flowers are hidden, and that is fixable

Garden balsam does not hold its flowers out on top the way bedding impatiens does. Each bloom sits in a leaf axil, tucked tight against the thick upright stem, and the leaf immediately above it arches over and covers it completely. A plant in full flower can look like a plain green column from three feet away. Walk up to it, bend down, part the foliage with your hand, and there are twenty flowers you could not see.

The fix is to strip the leaves off the flowering part of the stem. Take the leaf that shades each bloom, and generally every leaf on the lower half to two thirds of the stem, leaving the growing crown of foliage at the top intact. The plant is left looking like a small palm with a flowering trunk, which is exactly how it is grown where it is grown seriously. Nothing else in the border reads that way, and it is the reason to bother with the species at all.

This does not hurt the plant. Those lower leaves are already shaded by the canopy above them and contribute very little; the top rosette does the work. Strip them by hand, snapping downward so the leaf comes away cleanly at the stem, and do it progressively as the flowering zone moves up the stem through the season rather than all at once. Start when the first flowers open in the lowest axils and keep pace with them.

It collapses when dry, and it collapses fast

The stems are thick, translucent and almost entirely water, with no woody tissue anywhere in the plant. That makes garden balsam one of the fastest things in the garden to fold over when the soil dries, and one of the fastest to recover. A plant in a pot on a hot afternoon can go from upright to lying flat across the rim in two hours. Water it thoroughly and it stands up again by evening.

One collapse costs you nothing. Repeated collapses cost you flowers. Every time the plant wilts hard it drops the buds it was carrying in the lower axils, and those buds do not come back, so the flowering zone on the stem develops gaps that stay there all season. Aim to water before wilt rather than after it, which in practice means a good soak every second day in the ground and daily in containers through warm weather.

Water at the base rather than over the top. Wet foliage sitting overnight in a still, shaded spot is how powdery and downy mildew get started, and garden balsam is grown in exactly the damp shady conditions those diseases like. Mulch with two inches (5 cm) of compost, kept an inch clear of the soft stem, and the watering interval roughly doubles.

A plant that wilts by mid morning rather than mid afternoon is either potbound or standing in more sun than it wants. Check the drainage holes for roots before you assume it needs more water; a balsam that has filled its pot cannot be watered often enough to keep up in high summer.

Feeding, staking and keeping the stem straight

Feed lightly. A half strength balanced liquid feed every two to three weeks through the growing season is plenty. Push it with high nitrogen and you get an enormous soft leafy plant with the flowers even more deeply buried than usual, and stems so brittle they snap at a knee. If the leaves are large, dark and floppy and the flowering has thinned out, stop feeding for a month and let it firm up.

The taller forms reach two to two and a half feet (60 to 75 cm) on a single unbranched stem, and that stem is heavy with water and top heavy with foliage. Wind and heavy rain snap it clean off at the base, and there is no recovery from that: with no side shoots below the break, the plant is finished. Put a cane in behind the stem when the plant passes 18 inches (45 cm), before it needs one, and tie it loosely in two places with soft twine.

Whether to pinch is a real choice rather than a default. Leave the tip alone and you get one tall spire with a long, dense flowering column, which is the effect the species is grown for. Pinch out the tip at around six inches (15 cm) and you get three or four shorter branching stems, more flowers overall, less wind risk, and none of the palm tree look. Decide before the plant is knee high, because pinching a tall plant later just leaves a blunt stump.

1. Strip the shading leaves Work up the stem from the bottom, snapping off every leaf on the flowering section, particularly the one arching directly over each bloom. Leave the top eight to ten leaves as the working crown. Repeat every week or two as flowering moves up.
2. Cane before it leans Push a three foot (90 cm) cane in two inches (5 cm) behind the stem while the plant is still small enough that you will not spear the roots. Tie at 12 inches (30 cm) and again at 24 inches (60 cm), loose enough to slide a finger under.
3. Pick off pods as they form Fat green pods appear below the open flowers within about a fortnight of a bloom fading. Pinch them off carefully unless you want seedlings next year; a plant left to set seed slows its flowering noticeably.

What to write down

Two notes make next season easier. The first is the date you started stripping leaves and how the plant looked a fortnight later, because most people leave it far too late the first year and are surprised how much difference it makes. The second is which plants you pinched and which you left as single spires, with their final heights, so you can decide what to do with the whole batch next time rather than guessing.

Also record where each plant stood and how often it needed water there. Garden balsam is unusually sensitive to position: the plant in the damp shade of a north wall and the plant six feet away at the corner of the bed will not behave like the same species. That map of your own garden is worth more than any general watering advice.