Procedure
How to Condition Cut Flowers
Conditioning is the set of steps that happen once, in the first hour, before a bouquet sits anywhere. Done correctly, it is the difference between a rose that reaches day 7 and one that droops by day 3. Done wrong or skipped, no amount of daily care afterward fully makes up for it.
The numbers behind each step
| Step | Amount | Why |
|---|---|---|
| Recut angle | 45°, underwater | A flat cut in air seals against the vase wall within hours |
| Length lost per recut | 1–2 cm | Removes the sealed or air-dried tissue |
| Vase water volume | 1–2 L per 10 stems | Keeps cut ends submerged below the foliage line |
| First-24-hour uptake | up to 5% of bunch weight | A 500 g bunch takes roughly 25 ml per stem per day |
| Commercial flower food | 20–50 g sugar/L, pH 3.5–5.0 | Acidified water speeds uptake; sugar alone feeds bacteria |
| Home bleach substitute | 2–5 ml per 4 L (≈0.02–0.05%) | Suppresses stem bacteria for 3–5 days |
| Water change interval | every 2 days | Stops submerged leaf rot and cloudy water |
| Pre-conditioning storage | 2–4°C shop / 4–10°C home fridge | Slows respiration before the flowers are arranged |
The conditioning procedure
- Strip foliage below the waterline0–5 min Every leaf that would sit underwater comes off, not just the ones in the way. Typical failure: a few leaves left on "because they looked fine" rot within 48 hours and cloud the whole vase.
- Recut each stem underwater5–15 min A 45-degree cut, 1–2 cm up from the existing end, made while the stem tip is submerged in a bowl or under a running tap. Typical failure: cutting in air lets an air pocket form at the cut face, which blocks the stem's vessels before it ever reaches the vase.
- Measure and fill the vase water15–20 min Roughly 1–2 litres of clean water for a standard 10-stem bunch, enough to cover the cut ends below the foliage line. Typical failure: eyeballing the water level instead of measuring, leaving too little for the first 24-hour uptake spike.
- Mix the preservative20–30 min Commercial flower food at the printed dose (equivalent to roughly 20–50 g sugar per litre plus acidifier), or the home substitute of 1–2 teaspoons (2–5 ml) of 5–6% household bleach per 4 litres of water. Typical failure: adding plain sugar water without an acidifier or the bleach substitute, which feeds bacteria instead of the stem.
- Arrange and place30–45 min Set the finished arrangement in an 18–21°C room, away from direct sun, heater draughts and ripening fruit. Typical failure: placing the vase on a sunny windowsill "to show it off," which can roughly halve vase life compared to a cool room.
- Recheck water at hour 24Hour 24 Top up if the level has dropped, since uptake in the first day can reach 5% of the bunch's weight. Typical failure: assuming a full-looking vase at hour one is still full a day later.
Questions we actually get
Frequently asked
Can I use aspirin or a penny in the water instead of flower food?
Neither has the two things that matter: a measured sugar dose (20–50 g per litre) and an acidifier that gets the water to pH 3.5–5.0. If you do not have flower food, the tested substitute is 1–2 teaspoons of household bleach per 4 litres of water, which suppresses bacteria without feeding it.
How much water do I actually need for a hand-tied bouquet?
A standard 10-12 stem retail bunch needs roughly 1–2 litres. A larger 12-24 stem hand-tied bouquet needs proportionally more, scaled so the cut ends stay covered but the foliage line stays clear of the water.
Is it safe to cut stems with regular kitchen scissors?
Sharp scissors or secateurs work, as long as the blade is clean and makes a single angled cut rather than crushing the stem. A crushed stem end has the same blocking problem as a flat, air-sealed cut.