Gadenin日本語Get the appPinch out the first bud and gain the whole season
Left alone, a zinnia runs a single stem up and puts one flower on the top of it. That flower is usually the biggest the plant will ever make, and it sits on a short thick stem with the leaves crowded underneath. Take that first bud out and the plant redirects into the side shoots at the leaf joints below, and within a month you have eight to twelve stems where there was one.
The gain is not just in count. Side stems are longer, more slender and better spaced for cutting, and because the plant now branches from low down it is shorter and far less likely to blow over. For anyone growing zinnias to pick, this is the difference between a handful of thick stumpy flowers and an armful of usable stems.
Pinching costs you about ten days on the first flower and buys you roughly triple the flowers over the season. There is no version of that trade worth refusing unless you specifically want one enormous show bloom.
- Wait for three or four sets of true leaves The plant should be 8 to 12 in (20 to 30 cm) tall with a visible central bud or growing tip. Pinching before it has leaf joints to break from just checks growth.
- Count down three or four leaf pairs Find the top of the plant, then move down past three or four pairs of leaves. That is where you cut, not immediately under the bud.
- Cut cleanly just above a leaf pair Use snips or your fingernails and take the whole top off a quarter inch (6 mm) above the leaf joint. You are removing more of the plant than feels comfortable, and that is correct.
- Leave it alone for two weeks Side shoots break from every remaining leaf joint within 7 to 14 days in warm weather. Do not pinch a second time. Zinnias only need one.
Do not pinch a plant that already has an open flower or a bud showing color. At that point cut the flower with a long stem instead, which achieves the same branching and gives you something to put in a vase.
Cut and come again is literal, not a slogan
Every time you take a stem off a zinnia, two shoots break from the leaf joint below the cut. Cut those two and you get four. This is why a bed of zinnias that is picked hard every few days ends the season with more flowers on it than one that is left to look pretty, and it is the single reason zinnias are the standard beginner cut flower.
The corollary is that a plant nobody picks slows down. Once a flower is left to fade and set seed, the plant reads that as its job being done and pushes fewer new buds. A zinnia bed goes noticeably flat within three weeks of being neglected and does not fully recover.
Get into a rhythm of going down the row every three or four days with snips and a bucket. Take anything open, take anything faded, and take them on long stems rather than snapping the heads off. Even if you have nowhere to put the flowers, cutting is doing the plant good.
| Action | What the plant does | Effect on the season |
|---|---|---|
| First bud pinched at 8 to 12 in (20 to 30 cm) | Breaks 8 to 12 side stems from lower joints | Roughly triples total stem count |
| Flowers cut on long stems every 3 to 4 days | Two new shoots per cut, repeatedly | Keeps production climbing into late summer |
| Faded flowers left on the plant | Sets seed and slows bud production | Flowering tails off within 2 to 3 weeks |
| Whole plant cut back by a third when tired | Flushes new growth from the base | Buys 4 to 6 more weeks if frost is still distant |
Cut deep and use the wiggle test
Do not snip a flower off just below its head. Follow the stem down to the next set of leaves or to a junction with a strong side shoot and cut there, which usually means taking twelve to eighteen inches (30 to 45 cm) at a time. Cutting deep is what forces long stems on the regrowth. Short cutting trains the plant to produce short stems.
Zinnias do not continue opening after cutting, so timing matters. Hold the stem six inches (15 cm) below the flower and shake it gently. A stem that is ready stays stiff and the flower barely moves. One that is not ready flops and wobbles like a bell on a spring, and that flower will collapse in the vase within a day. This is the most reliable ripeness test in cut flower growing and it takes a second.
Cut in the cool of early morning, strip the leaves that would sit below the waterline, and get the stems into water straight away. Cut at the right stage a zinnia lasts seven to ten days in a vase, which is far longer than most people expect.
Zinnias are dirty in the vase. The stripped leaves and the hollow stem foul the water fast, so change it every two days and the flowers last twice as long.
When it stops flowering, look at these four things
A zinnia that has stopped producing almost always has one of a short list of causes, and none of them is mysterious. Work through them in order rather than reaching for a feed, because feeding is the wrong answer to three of the four.
Too much shade is the commonest. Zinnias want at least six hours of direct sun and preferably eight. In less than that they grow tall and thin, flower sparsely and mildew badly. Nothing you do to the soil compensates for a shaded site.
Next, seed set. Check for old flowers left on the plant with dry brown centers. Strip every one and the plant will usually come back within two weeks. Then nitrogen: a dark leafy plant with no buds has been fed too richly, so stop feeding entirely. Finally, exhaustion late in the season, where a plant that has been cropping for ten weeks simply needs cutting back by a third to flush again.
| Symptom | Cause | Fix |
|---|---|---|
| Tall thin plant, few flowers, pale leaves | Less than six hours of direct sun | Move it or accept it. Sow the next batch in full sun |
| Plenty of foliage, dark green, almost no buds | Too much nitrogen | Stop feeding. Switch to a high potassium liquid feed at half strength |
| Flowering slowed after a good start | Old flowers left to set seed | Strip every faded head, cut hard, resume in 2 weeks |
| Small flowers on short stems after 10 weeks | Plant is exhausted | Cut the whole plant back by a third and water it in |
| Buds forming but drying up before opening | Drought stress or thrips in the bud | Soak the ground deeply. Open a dried bud to check for thrips |