Gadenin日本語Get the appThe shape of the pansy year
Pansies are cool season plants, and the calendar follows from that single fact. They germinate in cool conditions, root through autumn, flower whenever the weather is mild, sit through hard cold without dying, surge again in early spring, and then collapse when summer heat arrives. Everything in the schedule is arranged either to give them enough cool weather at the start or to get the display over before the heat ends it.
That leads to two viable patterns. In mild climates, sow in late summer, plant out in early autumn, and take a display that runs from mid autumn through to late spring with a quieter spell in the coldest weeks. In climates with hard winters, sow in late winter under cover, plant out in early spring, and take a display that runs from early spring until it gets hot. The late summer sowing is by far the better value where it is possible, because it produces months of flower at a time of year when little else is doing anything.
The mistake that spoils either pattern is planting too late. A pansy needs four to six weeks of active root growth before it faces cold or heat, and one that has not had that time never performs, however carefully it is looked after afterwards.
| Stage | Timing | Main jobs |
|---|---|---|
| Sowing for autumn planting | Ten to twelve weeks before your first frost | Sow in trays in a cool shaded place at 65F (18C) |
| Germination | Ten to fourteen days after sowing | Cover the seed lightly; darkness helps; keep cool |
| Transplanting seedlings | Two to three weeks after germination | Move to plugs at the first true leaves; keep cool and bright |
| Growing on | Four to eight weeks after sowing | Half strength feed, pinch once, harden off gradually |
| Planting out | Early autumn, soil above 45F (7C) | Space six to eight inches (15 to 20 cm); water in; slug protection |
| Late autumn | Plants filling out and flowering | Deadhead twice weekly, feed every two weeks |
| Deep winter | Growth stalled by cold | Stop feeding, clear dead leaves, check for frost lift |
| Late winter | First mild spells | Resume feeding, cut back leggy plants by half |
| Spring | Peak flowering | Deadhead twice weekly, feed every two weeks, watch aphids |
| Early summer | Plants stretching, flowers shrinking | Cut back and shade, or clear and replace |
Late summer: sowing for the long autumn to spring display
Sow ten to twelve weeks before your first expected frost. That is the timing that produces a plant with a solid crown and a working root system by the time the cold arrives, and it is the whole basis of the autumn planting. Sow later and you get a small plant that spends winter surviving rather than flowering; sow much earlier and the seedlings have to be nursed through the hottest weeks of the year.
The difficulty is that you are germinating a cool season seed in the warmest part of the year. Pansy seed germinates best between 60F and 68F (15C and 20C) and germination falls away sharply above 75F (24C). Sow in trays in the coolest shaded place you have, not in the open garden. Cover the seed lightly with a shallow layer of compost, roughly an eighth of an inch (3 mm), because unlike many small seeds pansies germinate better in darkness. Keep the compost just damp and expect seedlings in ten to fourteen days.
Transplant at the first true leaves into plugs or small pots, handling the seedlings by a leaf and never by the stem. Grow them on cool and as bright as you can manage; warm and dim produces long floppy seedlings that never make a decent plant. Give a half strength liquid feed weekly from about two weeks after transplanting seedlings, and pinch the tip out once to get two shoots instead of one.
Autumn: planting out and the first flowering
Plant out in early autumn while the soil is still warm, ideally above 45F (7C), so that the plants root out over four to six weeks before the weather turns. Space them six to eight inches (15 to 20 cm) apart, set the crown level with the surface, water in once thoroughly and put slug protection in place on the same day. Pick off every open flower as you plant.
Flowering begins within two to three weeks of planting and runs through the mild part of autumn. This is when the deadheading routine has to start and has to stay consistent: twice a week, taking the whole flower stalk down to the crown, so no seed pod is ever left to form. Feed at half strength every two weeks. This autumn flush is the reward for the late summer sowing, and it is often the best display of the whole year.
As the nights get properly cold, growth slows and the flower count drops. That is expected. Clear fallen leaves off the plants, because a pansy buried under wet leaf litter through a damp winter rots in the crown, and stop feeding once growth has visibly stopped, since nutrients applied to a dormant plant simply wash away.
Note your sowing date and the date the first flower opened after planting. The gap is remarkably consistent in a given garden, and once you know it you can work backwards from when you want the autumn display and sow to hit it.
Winter and spring: holding on, then the second surge
Through the coldest weeks the plants mostly hold rather than grow. Established pansies take hard frost and come back; the leaves go limp and dark during a freeze and stand up again as it thaws, which alarms people every year and is normal. The two jobs are to keep dead material cleared out of the crowns and to check after each freeze and thaw cycle for plants that have been heaved partly out of the ground, which are pushed gently back and firmed in.
At the first sustained mild spell in late winter, resume the half strength feed every two weeks and go over the plants. Anything that has become leggy and open in the middle gets cut back by half, above leaf joints, and will be flowering again within two to three weeks. Doing this at the start of the mild weather rather than in the middle of spring is what produces a dense plant for the peak season instead of a sprawling one.
Spring is the heaviest flowering of the year and the heaviest deadheading. Twice weekly, whole stalks, no pods. Aphid numbers climb quickly through mild spring weather, so check the buds and shoot tips at the same time. Keep feeding every two weeks right through, because a plant flowering this hard in soil that has been leached by winter rain runs out of nutrients faster than it looks.
Early summer: knowing when to stop
When daytime temperatures settle above 75F (24C) the plants stretch, the flowers shrink and pale, and the display goes downhill fast. Moving containers into afternoon shade and cutting the plants back by half can extend things by a few weeks in a cool summer, and in a hot one it will not. This is the natural end of a pansy's season and not a failure of care.
Clear the plants once they are past it rather than leaving them in place. Exhausted pansies left through summer become a reservoir of leaf spot, mildew and aphids for whatever you plant next, and any that are allowed to ripen seed will scatter it. Tip out container compost rather than reusing it, and do not put pansies back into the same piece of ground next autumn if you can avoid it, because black root rot builds up in soil that grows them repeatedly.
If you want to save seed from a plant you liked, that is the one situation in which you deliberately stop deadheading. Let a few flowers on one plant set pods, wait until the pods turn upward and start to pale, and collect them before they split, which they do explosively. Accept that this plant will stop flowering as a result, and keep it separate from the ones still on display.
Record the week the plants collapsed in the heat alongside the week you planted them. Over two seasons those two dates give you the exact length of the useful display in your own garden, which is what decides whether the late summer sowing or the late winter one is worth the effort where you are.