Is this plant worth saving, or should I replace it?

Gardeners keep dead plants for months. Partly it is hope, partly it is the sunk cost of what was paid for it, and partly nobody ever tells you that pulling a plant out is an allowed move. It is, and it is often the correct one — a struggling plant occupies the space, the light and the water that a healthy replacement would use, and the year spent nursing it is a year the border does not grow.

Step by step

1. Find out whether anything is alive.Scratch the bark of a stem with a thumbnail, starting near the top and working down. Green or white beneath means living tissue; brown and dry all the way down means that stem is dead. Then feel the crown at soil level — firm is good, soft or hollow is not.
2. Look at the roots.Slide a container plant out of its pot, or push a fork under a border plant and lift. Firm, pale, springy roots with white tips can rebuild a whole plant. Brown, limp roots whose outer sleeve slides off when pulled cannot, and if almost nothing firm remains the decision is made.
3. Ask whether you know the cause.A plant that failed for a reason you have identified and can remove — a pot too small, a downpipe soaking it, a position in shade it will never tolerate, a pest — has a future. A plant that failed for reasons you cannot name will very likely fail again in the same spot.
4. Ask whether you can actually remove that cause.Some causes are not removable at householder level: heavy shade from a neighbour's mature tree, a fundamentally waterlogged corner, soil that is wrong for the plant. If the answer is to change the plant rather than the place, change the plant.
5. Weigh what the plant is worth.Age, cost, rarity and sentiment all count. A mature specimen tree, an inherited plant or something hard to buy justifies a season of nursing and a professional opinion. A bedding plant, an annual or a supermarket herb does not — replacing it costs less than the compost you would use.
6. Ask whether the problem can spread.Virus, honey fungus, box blight, clubroot and soil-borne wilts all put the plants around them at risk. That converts the question from can I save it into should I keep it, and the answer is usually to remove it and not replant the same family in that spot.
7. If you are keeping it, reduce the demand on the roots.Cut the top growth back in rough proportion to the root you have lost. A damaged root system cannot support a full canopy, and every leaf it holds is water it must supply.
8. Give it one growing season and judge only by new growth.Damaged leaves never recover, so they tell you nothing. What matters is whether the next flush comes out normal, normally sized and normally coloured. If it does not, you have your answer.

Tips

• Take cuttings before you decide. If the plant is worth having and any healthy shoot remains, a few cuttings cost nothing and give you the plant back even if the original dies.
• Buy the replacement before you dig out the original if it matters to the planting. A gap is a lot easier to accept when the new plant is already on order.
• A plant that has been struggling for three years in the same position is not being unlucky. It is telling you the position is wrong.
• Photograph it with a date now. In six weeks you will genuinely not remember whether it has got worse.

Common mistakes

• Feeding a plant that is failing — Fertiliser helps a healthy plant that has run out of nutrients. On a plant with damaged roots it is an additional injury, because the salts draw water back out of the roots.
• Repotting into a much larger pot to help it — A reduced root system cannot occupy a large volume of compost, so the surplus stays wet and finishes off the roots that were left.
• Keeping a virused plant because it still flowers — It is a reservoir. Aphids and secateurs will move the virus to everything related to it in the garden.
• Cutting a damaged evergreen back immediately — The dead outer growth shelters live buds behind it, and until spring you cannot tell which shoots are alive. Wait.

Questions people ask