Gadenin日本語Get the appPinch at four pairs of leaves and mean it
Left alone, a snapdragon puts up one central spike, flowers, and then thinks about side shoots. Pinch out the growing tip when the plant has four pairs of true leaves and you get something quite different: every leaf axil below the cut breaks into a shoot, and a single plant carries eight to twelve spikes instead of one. The flowers are slightly shorter and thinner, which is exactly what you want in a border, and the total flower count is several times higher.
Do it while the plant is still small, in the tray or in the first week or two after planting out. Take out the top half inch (1 cm) with finger and thumb or a clean snip, cutting just above a pair of leaves. There is no need to be precise about it, but there is a need to be early: pinching a plant that is already six inches (15 cm) tall with a spike forming just wastes the growth it has made.
The one case for not pinching is if you want long single stems for cutting. An unpinched plant gives one tall straight spike of maximum length and thickness, and growers of cut flowers deliberately leave the tip alone for that reason. For a garden display, pinch everything.
After the pinch, leave the plant alone for two or three weeks. It will look like nothing is happening while it builds side shoots, then it thickens up quickly. Do not pinch a second time. Repeated pinching delays flowering without adding much, and by then the branching pattern is already set.
- Count four pairs of true leaves The seed leaves do not count. Wait until there are four pairs above them, which is usually a plant three to four inches (8 to 10 cm) tall, in a cell or newly planted out.
- Take the tip out cleanly Pinch or snip just above the top pair of leaves, removing the growing point and the tiny leaves around it. Half an inch (1 cm) is enough; you are not cutting the plant back.
- Wait, and do not repeat Side shoots break within two weeks. Leave them all rather than thinning them, and do not pinch the side shoots in turn unless you want to push flowering back by a month.
- Support before the shoots get long A pinched tall plant carries a lot of top weight. Push in a cane or a set of twiggy sticks now, while the roots are still shallow, and let the shoots grow up through the support.
Water at the base, feed lightly
An established snapdragon copes with dry weather better than most border plants, and the way to keep it that way is to water deeply and infrequently rather than a little every day. A gallon (4 liters) over the root area twice a week in hot dry weather drives the roots down. Frequent sprinklings keep them shallow, and a shallow rooted plant wilts in the first heatwave.
Always water at the base and not over the foliage. Snapdragon leaves that stay wet overnight are the starting point for rust, which is the disease that ends most plantings, and a hose left running under the plant costs nothing extra to do properly. Morning watering is better than evening for the same reason.
Feed is a matter of restraint. Work some compost into the bed before planting and give a balanced liquid feed every three or four weeks once the plants are flowering, and that is enough. High nitrogen feeds give you a big soft leafy plant with fewer flowers, and that soft growth is precisely what aphids and rust colonise first. If the leaves are dark green and the spikes are short, you are overfeeding.
Mulch with an inch (2.5 cm) of compost or fine bark after the ground has warmed. It holds the moisture that keeps flowering going, keeps the lower leaves out of the splash zone where rust spores travel, and saves most of the weeding in a bed that is otherwise awkward to hoe.
| Task | Timing | Detail |
|---|---|---|
| Pinch the tip | At four pairs of leaves | Once only; turns one spike into eight to twelve |
| Water | Twice weekly in dry heat | Deep soak at the base, never over the leaves |
| Feed | Every 3 to 4 weeks in flower | Balanced liquid feed; avoid high nitrogen |
| Mulch | Once the soil warms | 1 inch (2.5 cm), kept clear of the stem base |
| Deadhead | As spikes fade | Cut the whole spike out, not just the top flowers |
| Cut back hard | When flowering stalls in heat | Take spikes to a third of their height; expect a second flush |
| Stake | Before shoots reach 12 inches (30 cm) | Canes or twiggy sticks; tall types only |
| Check for rust | Weekly from midsummer | Turn leaves over and look for orange pustules |
Cutting back is the whole trick with snapdragons
The single most useful habit is cutting spent spikes right back rather than picking the dead flowers off the top. Once the flowers on a spike have opened from the bottom up and the top few are going over, that spike is finished. Cut it out low, down to a third of the plant's height, where you can see small shoots waiting in the leaf axils. Those shoots become the next round of spikes.
Snip off only the brown tips and you leave the plant carrying a stem that is putting energy into seed pods. Seed pods are the off switch. A plant that is allowed to set seed slows down and then stops, and no amount of feeding restarts it, so removing whole spikes before pods swell is what keeps a planting flowering from early summer into autumn.
In midsummer heat, flowering stalls regardless. Above 85F (29C) the plant simply stops initiating new flower buds, spikes get short, and color fades. This is the moment for a hard cut back rather than a rescue attempt: shear the whole planting down by half to two thirds, water it, give a light feed, and leave it. It will sit and look untidy for two or three weeks and then, as soon as the nights cool, come back with a second flush that often beats the first.
Keep cutting spikes for the house all season. Cut in the morning, when about a third to half the flowers on a spike are open, and take the stem low. Cutting is the same operation as deadheading, done a fortnight earlier, and a plant that is cut from regularly flowers harder than one that is admired from a distance.
Support, tidying, and what to record
Tall types need support, and it has to go in early. A spike three feet (90 cm) tall with a full head of flowers catches wind and rain like a sail, and once a plant has gone over at the base it never stands properly again. Push in canes or a ring of twiggy sticks when the shoots are under a foot (30 cm) and let the growth come up through them. Dwarf and intermediate types generally hold themselves up.
Keep the base of the plant clear. Pull weeds, remove any yellowing lower leaves, and do not let a mulch pile up against the stem. Airflow at ground level is the cheapest rust prevention there is, and lower leaves lying on damp soil are where the first pustules almost always show up.
Record the date of the pinch, the date of the first open flower, and the date you cut back for the summer. Those three dates, kept across a couple of seasons, tell you exactly how many weeks your own garden takes from pinch to flower and how long the gap between flushes really is, which lets you time the cut back so the second flush lands when you want it.
Also note the position of the plants that stood up without staking and the ones that flopped. That is usually a light and wind difference rather than a plant difference, and marking it on a simple sketch of the bed saves you staking the whole planting next year when only one end of it needed it.
Cut back for the second flush before the plants look completely finished, not after. A planting sheared while the foliage is still green and healthy regrows in two to three weeks. One left until the leaves have yellowed and rust has taken hold has nothing left to regrow from, and cutting it then simply kills it.